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Lupine publishers|Exploring Connections in Agroecosystems

Exploring Connections in Agroecosystems

Abstract

A challenge of the Anthropocene is to advance human development without undermining critical natural processes. At the heart of this challenge is a better understanding of the interactions and feedbacks between nature, ecosystem services, and human wellbeing, in dynamic and complex social-ecological systems. These interrelationships have been the focus of much work in the past decades, however, more remains to be done to identify and quantify them, at different scales.

Keywords: Agroecosystems; Ecosystem Service; Resilience; Soil Functions; Research Frameworks

Introduction

Agroecosystems as described by Gliessman [2] is a framework with which to analyze food production systems as wholes including their complex sets of inputs and outputs and the interconnections of their components parts. Agroecosystems are ecological systems transformed and simplified for the purpose of producing food, fiber, or other agricultural products Falco, et al. [1] They are very productive suppliers of biomass-related provisioning ecosystem services, e.g. food, timber, and energy. At the same time, they are connected and highly dependent with natural ecosystems, particularly with soils’, and their ecological principles and conditions, such as soil fertility, water supply or soil erosion regulation. Human transformation and alteration of ecosystems, for the purpose of converting natural landscapes for establishing agricultural production, makes agroecosystems very different from natural ecosystems. However, some of the characteristics, structure and processes of natural ecosystems are still fundamental in agroecosystem’s function. Assessments of this interplay of ecosystem conditions and services are very important to understand the relationships in highly managed systems. (Figure 1) illustrates the dynamic processes occurring within an agroecosystem. Solid lines represent the flows of energy, whereas dashed lines show movements of nutrient. It is crucial to understand these processes because the function of the agroecosystem will determine the difference between the success and failure of management practices Gliessman, et al. [2].

Figure 1: Functional components of an agroecosystem (Source: adapted by Gliessman, et al. [2])

Soil ecosystem services (ES), which are of particular importance for agroecosystems, are the maintenance of the genetic diversity, the nutrient cycles, the biological control of pests and diseases, erosion control and sediment retention, and water regulation Swift, et al. [3]. Soil ES have been the subject of multiple scientific researchers over the years. Ecologists and biologists are studying the supporting services and ecosystem processes of soil, i.e., soil formation, soil binding by vegetation. Benefits for human beneficiaries more often are translated into economic values studied by social scientists, i.e., avoided erosion and sedimentation, water for agriculture. Agroecosystems depend on ES to function and be productive. Sustain ES ensures the resilience of agroecosystems as pointed to meet the stress of global challenges. Soil is a vital pore for life, representing an economic asset, particularly for agriculture, which is one of the main activities of the use of soil resources. Global changes increasingly influence soils, their biodiversity, and the ecosystem services that they provide. Since the agricultural sector constitutes a significant part of the economy of several countries, this indicates the need for sustainable soil and land management practices. Different land-use planning, mechanisms, and policies could mitigate some effects of agricultural expansion by identifying where soil natural capital is limiting and how it can be improved. The unique role of soils in influencing the management and use of other resources such as water, land, nutrients, and biodiversity validates the efforts of the scientific community towards integrated resource management. Agriculture, and consequently, soils are at the heart of the Sustainable Development Goals (SDGs) and fundamental to achieving them. The SDGs lay the groundwork in the quest to achieve a healthy and sustainable future for our planet. The unique position of soils as a link between the use and management of other natural resources makes it useful in the overall assessment of ecosystems allowing relevant actors and stakeholders, e.g., scientists, economists, policymakers, to connect different SDGs and actions towards a common goal Keesstra, et al. [4]. For instance, SDGs 2, 3, 6, 13, 14, and 15 have targets that explicitly bind them with soil functions and ecosystem services. The success of the SDGs rests, to a large extent, on effective accounting, monitoring, review, and follow-up processes.

Proposed framework for agroecosystems

This section aim is to explore the links between anthropogenic activities and the ecosystems, focusing on the intersection of agroecosystems, soil natural capital and human well-being. Critical physical and social components of human well-being are dependent on well-functioning ecosystems, e.g.., quality and quantity of nutritious food, clean water, stable income, integrated communities, preservation of ecology. The objective is to provide a broader conceptual framework that consistently accounts for the above relationships, also exploring the feedback effects. ES are defined as the beneficial flows (amount per unit time) of services-depend on natural capital stocks (total amount)-from ecosystems to societal groups and fulfill human needs. For instance, soil structure can supply nutrients. The provision of the ecosystem service ‘support plant growth’ depends on the amount of soil organic carbon in the soil (stock) and the timing of the availability of the storage volume regarding a land use change. Furthermore, the value of these services depends on the beneficiary’s usage. The important first step is to frame and understand the interacting ecological and societal processes in interest. A Driver-Pressure- State-Impact-Response approach is a framework that captures the cause-effect relationships of a system and assisting in many steps of the decision process Lewison, et al. [5]. This framework could be used for structuring problems and facilitating empirical research for agroecosystems planning. The DPSIR framework starts by identifying the various driving forces, e.g., political, economic, ecological, demographic, and social, that cause direct pressure on the state of SESs and impact their ability to deliver a range of ESs. Eventually, changes in SESs lead to societal responses to mitigate pressures Rounsevell, et al. [6]; Gupta, et al. [7]. The framework in (Figure 2) assumes cause–effect relationships between interacting components of social, economic, and environmental systems, which are described below and exemplified through the issue of land use and soil natural capital and ES provision:

a) Driving forces of natural and anthropogenic change (e.g., increasing atmospheric greenhouse emissions and land use change) b) Pressures on the SES (e.g., soil degradation and livestock emissions) c) State of the environment (e.g., lowered crop production) d) Impacts on population, economy, ecosystems (e.g., food insecurity) e) Response of society (e.g., policy response, such as the Kyoto protocol for reducing greenhouse gas emissions and car or the EU Common Agricultural Policy).

Pressures refer to the state of the natural capital stocks and processes, which in turn affect the input flows in the agroecosystem. Ecosystem services flow from natural capital stocks and processes and create benefits and value for the societies. This interpretation of state deviates from suggestions within the scientific community Sch¨oßer, et al. [8]; Helming, et al. [9] who have continued to consider ES changes as parts of the state, and have evaluated impacts only in terms of changes in human well-being. I argue, however, that social aspects of agroecosystems are defined as contributions to human well-being, and changes of these can therefore be best assessed as parts of the state component. In this framework, I use an example of an agricultural area as a demonstration. The value of agricultural land is based on three factors, productive capacity, location, and beneficiaries. The service is the part of an ecosystem function, which is the supply that intersects with human locations and activities. So, it is important to define a context to delineate the area over which this service operates and where the demand for the service is. The area should be selected in terms of potential service improvement by paying attention to the relationships and trade-offs between soil ES and land assets and people’s access to these values. Finally, to better understand how each of the system’s dimensions varies and interacts requires adequate monitoring and assessment of all its components and the subsequent dissemination of data and products. Based on available data for the research area, a causal analysis can be performed to explore the relationship between different drivers and identify those that significantly influence ES and human well-being. The description of all the causal chains of the framework will allow selecting the indicators that significantly impact the DPSIR sectors. Despite existing investigations, less work has been done on demonstrating the mutual

Discussion

Apart from describing the relationships in figure 2 conceptually, it remains to quantify and address them physically in terms of spatial boundaries, relations and synergies with the surrounding social and natural world and distinguish the different sources of inputs to an ecosystem Bagstad, et al. [11]. A critical point that remains a challenge within the conceptual frameworks is to differentiate between ecosystems functions and processes, their services to human well-being and the generating benefits to avoid the double counting but also to use the correspondent indicators for their evaluation Silvia Silvestri [12]. (Table 1) presents an example of an initial set of indicators that could serve as a basis for the development of the described framework (Figure 2). Furthermore, to analyze potential future consequences of alternative land uses for both soil conservation and economic objectives, scenario analysis can be used identify determining factors.

Figure 2: Conceptual DPSIR framework for human-agricultural systems interaction cycle. The framework applies to the agricultural territory. The arrows represent the interplay of structure and processes. The structural part of the state components ‘Social system’ refers to human inputs such as sociotechnical networks, collectives, planning, or agroecosystem management. The ‘Monitoring and assessment involves the outline of a set of recommendations for indicators, monitoring procedures and the evaluation of the DPSIR steps. The text in the boxes is illustrative, not exhaustive. (DPSIR framework originally developed by the European Agency for Environment).

Table 1: Initial elements for building up the framework for valuing and quantifying ES in an agroecosystem.

Different scenarios can identify mixed strategies that could be used to compare with the baseline scenario, which does not account for any policy and further intervention for the role of soil ES in production decisions. In the DPSIR framework baseline scenario represents the increased pressures while the alternative scenarios are capturing response measures. The scenario approach will also allow assessing how choices in public policy can influence change by building different strategies considering various policy options. For example, as part of the global warming mitigation strategies, to estimate the reduction in CO2 emission caused by the sequestration of soil organic carbon (SOC), because of alternative farm practices that increased SOC storage. The most important for a practical analysis is to develop scenarios appropriate for the context and have the potential to yield information that advances decision making McKenzie, et al. [13]

Conclusion

This qualitative study demonstrates the potential of the DPSIR framework for analyzing and structuring leading cause and effects problems of agroecosystems. Thus, it is an aid to sustainable governance through developing strategies and targeted policies towards systems thinking approach. This framework identifies that, apart from the critical ecological aspects, social aspects of agroecosystems are defined as contributions to human well-being, and changes of these can therefore be best assessed as parts of the agroecosystem’s state. The discussed framework must be applied empirically to accurately monitor and quantify the multiple elements of the system status.

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lupine-publishers-oajess · 6 years ago

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The Elemental Composition of Soils of Saline Agrolandscapes and Sanitary-Hygienic Conditions of the Southern Part of the Prichanovskaya Depression

Lupine Publishers- Environmental and Soil Science Journal

Annotation

Studying the macro- and microelement composition of the soils of the saline agrolandscape of the southern part of the Prichanovskaya depression, it was established that meadow-chernozem poorly saline sandy soil was formed in the eluvial position, and low-saline solonchikovy clayey soil in the bottom. Of macronutrients in them is dominated by silicon. Calcium is more than magnesium, especially in the soil horizons of the lower position. The content of trace elements in the soil of the lower position is 2-3 times higher than at the top due to their movement with surface and groundwater. The content of arsenic, barium, boron and strontium is several times higher than the MPC, which creates a difficult situation in the area, which must be considered in the production of agricultural products.

Keywords: Saline agrolandscape; Catena; Macro and microelements; Sanitary and hygienic conditions

Introduction

Currently, agricultural production is undergoing great changes. The main direction of use becomes its greening on a landscape basis. The founder of this direction is BB Polynov [1]. The landscape is a large and complex dynamic system of the earth’s surface, within which interaction and interpenetration of the elements of litho, hydro, and atmosphere occur [2]. In connection with the agricultural use of the territory, a variety of landscape began to stand out-an agroland landscape, which takes into account all its peculiarities of development and existence-climatic, biological, lithological, soil, etc. Such major scientists - soil scientists as VA Kovda [3], Kiryushin VI [4], who were forced to look at this problem differently than in the previous research period. Earlier, in the development of zonal farming systems for the rational use of soil cover, zonal features of the territory were mainly taken into account. It turned out that with soils and living organisms in it and on it, scientific substantiation, accuracy and thoroughness of agrotechnical and ameliorative treatment is necessary. Underreporting and lack of knowledge of natural conditions, especially of the soil cover, is one of the reasons for low yields. With the scientifically based and effective management of soil fertility, two difficult tasks are solved: obtaining high and stable yields and increasing soil fertility. At the same time, it is important to know the chemical composition of soils belonging to a particular landscape and the direction of geochemical processes within it. The purpose of these studies is to study the chemical elemental composition of the soil and the sanitary and hygienic situation in the saline agrolandscape of the southern part of the Prichanovskaya depression, which is part of the Barabinskaya plain.

Research Tasks

a) To study the macronutrient composition of catena soils: meadow-chernozem ordinary low-power low-rich sandy loam-eluvial (high) part of the agrolandscape and meadow-marsh saline heavy clay-accumulative (low).

b) To determine the microelement composition of these soils and to identify the sanitary and hygienic environment of the studied saline agrolandscape. In fulfilling their goals and objectives, they used modern approaches to study selected agrolandscapes [4-6]. In 1990, an agromeliorative grouping of sone-almonds and recommended measures for their improvement were developed for sodic and saline soils in 1990 [7]. Currently, this group is outdated. It does not match the approaches to the development of adaptive-landscape farming systems. Therefore, an agroecological typology of lands of the Barabinskaya lowland was proposed, which underlies the present work [6].

Objects and Methods of Research

The studies were conducted in the southern part of the Prichanovskaya depression of the Barabinskaya lowland, which covers 65.5% of the territory of the Novosibirsk region or 11.7 million hectares. Here, in the immediate vicinity of Lake Chany, we laid two soil cuts in a saline agrolandscape in the form of catena. The incision (P40)-on the elevated mesorelief (eluvial position) and the incision (P21)-in the lower part (accumulative position).

The Location of the P40 Soil Section is as Follows

Chistyozerny region of the Novosibirsk region, dry meadow, eastern apical part of the margin of the mane (76° 45ʹ 09.08ʺ N). Height above sea level-120 m. The soil is a meadow-chernozem ordinary medium-power poorly mature sandy sand, and the P21 cut (54° 46ʹ 52.1ʺ.N., 76° 50ʹ 22.3ʺ E), height above sea level-103 m; grass-wormwood meadow, boils from HCL from the surface. Groundwater-from 60cm. Soil: meadow-marsh saline, heavy clay (Table 1) (Figure 1).

Figure 1: The location of the cuts on the saline agrolandscape (satellite image).

Table 1: Physico-chemical properties of catena soils in the saline natural landscape of the southern part of the Prichanovskaya depression.

Discussion of the Results

The gross content of 7 macroelements-Si, Fe, Al, Ca, Mg, Na, P (Table 2) was determined. From the data of (Table 2) it can be seen that the macro element Si dominates in the soils. On the eluvial position, its catena is twice as large as in the accumulative position, which is associated with weak leaching and movement of silicon by surface flows. Somewhat different There were results on the content of Ca and Mg. In both soils, the Ca content prevailed over the Mg content. With depth along the profile, the amount of calcium increased dramatically, especially in meadow-marsh saline soil, since the latter is located in a modern lakeside belt, where conditions are created for its enrichment in a biogenic way (during spill, die-off mollusks, etc.) and due to soluble salts. The magnesium content in both soils is distributed more or less evenly. With depth, its amount gradually increases, and in the accumulative zone it is almost 3 times more than in the eluvial one. The sodium content in the upper horizons of the meadow-chernozem soil (eluvial positions) exceeds the contents of Ca and Mg and is slightly less than in the hell and Al horizons of the marsh, which indicates a periodic enhanced leaching of these horizons during floods. Phosphorus is slightly more contained in the salt marsh in the accumulation zone, where natural conditions are created for its accumulation in anaerobic conditions.

Table 2: The profile distribution of the gross content of macroelements in the saline natural landscape of the southern part of the Prichanovskaya depression.

Summarizing the content of macronutrients in catena soils, it can be noted that the eluvial positions in the natural saline landscape in the hemihydromorphic soil profile contain less macronutrients than the soil profile in the accumulative positions by about 2-3 times. The issue of distribution of trace elements in the soil scientists pay great attention. In particular, a number of monographs on the Novosibirsk region and the city of Novosibirsk were published [8-10], where the authors highlight the problem of the great importance of trace elements in the life of plants, animals and humans. A brief description of the biological role of individual chemical elements, even those whose significance for living organisms is not enough or little is known [8]. The authors of this monograph conducted biogeochemical zoning of the territory of the Novosibirsk region. Thus, within the region, two biogeochemical provinces have been identified, which include 8 biogeochemical regions (BR). They are significantly different in environmental stress.

Object of Study

According to this regionalization, is located in the Barabinskaya Plain in the extensive biogeochemical province 1 (BGHP-1). It is characterized by a wide distribution of saline rocks and soils, mineralized groundwater, groundwater and surface water, a lack of Co and Cu, an unfavorable ratio in Ca: Mg plants. Here the most complicated biogeochemical situation has developed. This report provides an analysis of 14 microelements and examined their content depending on the position of the sections along the catenaupper (eluvial) and lower (accumulative) positions.

Pb is lead. In medicine and in biology, interest in this element is associated exclusively with its toxicity for all living things. However, it has now been established that lead in small amounts (for plants from 2 to 6mg/kg of dry matter and animals from 0.05 to 0.5mg/kg) is necessary for their normal life activity [11,12]. Plant resistance to excess lead is different-legumes are more resistant, and less so are grains. Signs of toxicity to an excess of lead in plants for this reason can occur when its total content in the soil varies from 100 to 500mg/kg [13,14]. The data we obtained (Table 3) indicate that for catena in eluvial and accumulative positions, the total lead content ranges from 10.5 to 26.0mg/kg of soil. This amount is significantly less than the MPC-100mg/kg [15]. In the upper humus horizons its content is found more, and in the lower-somewhat less. In the eluvial zone in the profile of the meadow-chernozem soil slightly less than the accumulative. Our data indicate that there is no significant change in the Pb content in the profile of both soils. Only in the hell horizon of the meadow-marsh saline soil, the amount of Pb increases to 26mg / kg of soil, which indicates its transformation from the upper eluvial positions to the lower accumulative ones.

Table 3: The profile distribution of the gross content of trace elements in the soils of the saline agrolandscape of the southern part of the Prichanovskaya depression.

As is arsenic. Arsenic has long been used both as a deadly poison and as a medicine, since it has healing and tonic properties. He, like other trace elements, in small quantities is necessary for living organisms and extremely dangerous in high concentrations. The biological role of arsenic is related to the fact that it is chemically close to phosphorus and can replace it in separate biochemical reactions. The phytotoxic threshold of arsenic in soils depends on the particle size distribution and properties-on light, low-humus soils with low absorptive capacity, it is 10-20mg/kg, and on heavy, high-humus with high absorptivity, it can exceed 100mg/kg [12]. MPC of arsenic in sandy and sandy sour soils does not exceed 2; in loamy and clay neutrals-10mg/kg. The arsenic data obtained by us (Table 3) indicates that in the top positions in the meadowchernozem soil along the profile it is distributed more or less evenly and ranges within 18mg/kg in the B2 carbonate horizon and slightly higher 21.6, which exceeds the MPC. More than 34.5mg/kg is found in the accumulative zone in the horizon of arsenic hell. In the lower horizons it is significantly less-13.0–15.5mg/kg. This is due to the heavier particle size distribution of the soil and the alkaline reaction of the environment. According to Russian regulations, these soils have a high arsenic content.

Cd is cadmium. Cadmium is known as a toxic chemical element, but recently it has been established that it stimulates the growth of animals and humans in small quantities. The need for cadmium for plants has not yet been established. Cadmium easily enters the plants through the root system, and from the atmosphere into the leaves. The main cause of cadmium toxicity for plants is that it disrupts the activity of enzymes, inhibits photosynthesis and makes it difficult for plants to enter a number of nutrients. MAC of cadmium in soil in different countries ranges from 2 to 5mg/kg, in water (mg/l) 0.05; in feed-1mg/kg of dry matter. According to Il’ina VB and Syso AI [8] in the Novosibirsk Region there is no dangerous entry of cadmium into plants from the soil, which is also confirmed by our data (Table 3). The number of Cd in the soil profile of the studied landscape is small. In the upper soil horizons of the eluvial positions, its content is 0.8, and in the lower horizons it is 0.9 mg/ kg, then some decrease occurs. In soil-forming rocks, the amount of cadmium increases in comparison with the middle horizons. There is an increase in cadmium in accumulative positions.

Ba is barium. Despite the presence of barium in many plants and animals, its physiological significance has not been established. Due to chemical similarity and antagonism with calcium and strontium, barium is able to displace them from plants. Plants easily absorb Ba, especially from acidic soils, and are able to tolerate its high concentrations. The MPC of barium in soils, food and feed has not been developed, and in drinking water it is 0.1mg/l [16]. As Ilyin VI and Syso AI noted [8] in the Novosibirsk region there may be an excess amount of barium in plants and in living organisms due to its high content in soils and waters. The data we obtained (Table 3) suggests that the Ba content in eluvial positions is high and varies along the profile of the meadow-chernozem soil from 543 in the parent rock to 676mg/kg in the humus horizon A. Significantly higher is its quantity respectively 1040 and 829mg/ kg, which indicates leaching and movement of Ba down the catena and accumulation in vegetation and living organisms.

B-bor. The biological functions of boron in plants are associated with the metabolism of carbohydrates, the transfer of sugars through membranes, the synthesis of nucleic acids and phytohormones. However, the mechanism of its action is not fully understood. In the south of Western Siberia there is practically no shortage of plant boron. Soils are rich in this trace element, and an excess of boron is a frequent occurrence here, especially in saline soils [17]. MPC boron in drinking water-0.5mg/l. An excess of boron in the soils of the Barabinskaya Plain is a serious environmental problem, both for plants and for animals and humans. A high concentration of boron in saline soils not only reduces the yield, but also causes boric enteritis, an endemic disease of the gastrointestinal tract in animals and humans. In the studied agrolandscape (Table 3), the boron content in the eluvial position is 38–57.8mg/kg of soil, and in the accumulative position, it is 2 times higher in the profile of the meadow-marsh saline soil, which creates serious sanitary and epidemic problems for this area of residence [18].

Mn is manganese. Manganese provides redox processes in plants, since it is able to change valence easily and reversibly transfer from Mn2+ to Mn7+. With a shortage or an excess of Mn, these functions are violated [12,19,20]. In plants, manganese is involved in the respiratory process, nitrogen metabolism, promotes the formation of chlorophyll and the synthesis of nucleic acids. In living organisms, manganese performs the same functions as in plants, but at the same time new, specific ones appear. It is needed for the body to produce insulin, the formation of the skeleton, the work of the central nervous system. According to Ilyin VB and Syso AI [8], in the Novosibirsk Region there are areas with both low manganese content and high, and anthropogenic impact on agricultural landscapes can increase both the deficit and excess of this element. Our studies have shown that in the eluvial positions of saline agrolandscape in the profile of meadow-chernozem soils, the gross Mn content does not exceed 855mg/kg, which is lower than the regulated sanitary and hygienic standards adopted in the soils of Russia (1500-3000mg/kg). In accumulative positions in the profile of meadow-marsh saline soil, the manganese content is somewhat higher-up to 1090 mg/kg in horizon A1. However, the ratio Fe/Mn is high and significantly exceeds the standard (1.5-2). This gives reason to consider this area unfavorable for the cultivation of cultivated plants (Table 4), because manganese deficiency is added to other adverse conditions.

Table 4: Fe/Mn ratio in the studied soils.

Cu-copper. Copper is involved in many physiological processes occurring in living organisms. In plants, these include photosynthesis, hemoglobin synthesis, respiration, redistribution of carbohydrates, etc. Such wide participation of copper in plant life is associated with its ability, as well as Fe, Mn, Co and Mo to change valence. Copper, like zinc, is responsible for reproductive functions. Its lack leads to a decrease in grain and its quality.

In Russia, MPC of copper for soils is set depending on its particle size distribution and pH value. In sandy and sandy soils, the MPC of gross copper content is 33; in loamy and clay sour-66; loamy and clay neutral and alkaline-132mg/kg. As can be seen from (Table 3), the gross copper content in the eluvial position in the profile of meadow-chernozem solodized soil ranges from 18.5 in horizon AB to 28.5mg/kg in horizon A. and more times more, which indicates the spatial movement of this element from the top to the bottom where it accumulates. Copper content below MPC is typical for all horizons of the studied soils.

Cr-chrome. Chromium, as a chemical element, is vital for living organisms, since in the processes of carbohydrate metabolism, it interacts with insulin, participates in the structure and function of nucleic acids and, possibly, the thyroid gland. The chromium content in plants ranges from 0.02-1.0mg/kg of dry matter. As a rule, plants under normal conditions do not lack it. MPC for chromium in Russia has not yet been developed. According to Kloke A [15], the MPC in animal feed should not exceed 20mg/kg. In drinking water in Russia, the MPC is 0.05mg/l. Researches by Ilyin VB and Syso AI found that no high and dangerous concentrations of chromium were found for the health of animals and humans in the soils of the Novosibirsk Region [8]. Our studies have shown that in eluvial positions, the gross chromium content in the meadow-chernozem soil is below the MPC. According to the profile, its quantity changes insignificantly and only in the horizon of AV it decreases sharply, which, apparently, is connected with the processes of podzolization and lassival. In accumulative positions in the profile of a meadowswamp soil, the chromium content increases and is on the verge of the MPC or slightly above it, especially in the A1 horizon-121mg/ kg, which may be due, on the one hand, to the movement of this chemical element with surface and underground waters, and on the other-with its accumulation due to the periodic flood of Lake Chany during the flood season.

Mo-molybdenum. As an element with variable valence, molybdenum in living organisms performs the function of electron carrier. In plants, molybdenum takes part in nitrogen exchange. It is a catalyst in the conversion of nitrites to nitrates, ensures the fixation of atmospheric nitrogen by nodule bacteria of legumes. The optimal ratio of Cu/Mo=4: 1. With a higher ratio, grazing diarrhea syndrome appears in cattle. As evidenced by the results of the research of Il’in VB and Syso AI, in the soils and plants of the Novosibirsk Region both a deficiency and an excess of molybdenum are possible. Its content in feed and plants below 0.2-2.5mg/kg of dry matter is considered critical, and non-dangerous-10mg/ kg. The MPC in soils is 5mg / kg [15]. Our research suggests that the molybdenum content in both the top and bottom positions is low and well below the MPC-from 3.6 to 2.05mg/kg (Table 3). It is about the same and its accumulation in the accumulative positions does not occur. However, there is a high ratio between Cu/Mo-up to 20 (Table 5). Consequently, in this natural landscape, the balance between copper and molybdenum is disturbed, which can cause diseases in animals and people.

Table 5: Cu/Mo ratio in catena soils of the saline natural landscape.

(Table 5) Cu/Mo ratio in catena soils of saline natural-Vvanadium. Vanadium is a necessary chemical element for living organisms, and for plants its significance remains unexplained. In plants, vanadium contains a little-up to 2mg/kg of dry matter, whereas in soils it is quite a lot. Vanadium was found to be involved in plant photosynthesis. With its lack of plants, the amount of chlorophyll is reduced. Like molybdenum, vanadium is a catalyst in the processes of nitrogen fixation from the air by nodule bacteria of legumes of the plant landscape In the Novosibirsk region in the diets of animals neither vanadium deficiency nor phytotoxicity is observed. According to Kloke A [15], the MPC of vanadium in soils is 100mg/kg; in Russia-150mg/kg, for food-5mg/kg and for drinking water-0.1mg/l. Our data indicate that the content of vanadium in the upper positions of catena in the profile of meadow-black earth soils varies from 55.0 to 70.1mg/kg. The profile distribution of vanadium is more or less evenly, except for the horizon AB, where a decrease in its content is observed. In accumulative positions there is its accumulation, but in quantities much smaller MAC. The maximum content of vanadium falls on the A1 horizon of the meadow-marsh saline soil and is 130mg/kg (Table 3).

Zn is zinc. Zinc is involved in many functions of living organisms. It is part of various enzymes involved in the metabolism of carbohydrates, proteins and phosphates and in the reproduction process. In higher plants, Zn, as a rule, accumulates in the seeds, where it is concentrated in the germ. The MPC of zinc in soils according to Kloke A [15] is 300mg/kg. In Russia, depending on the granulometric composition of the APC (gross) zinc in sandy and sandy soils-65; in loamy and clay (acidic)-110; in loamy and clay (neutral)-220mg/kg. In the studied agrolandscape, the total zinc content in eluvial positions ranges from 30 to 50mg/kg, which is significantly lower than the MPC. In the upper horizons it contains up to 50mg/kg (Table 3). In the horizon AB its quantity decreases and in the parent rock it increases again to 42mg/kg. In accumulative positions, the zinc content increases almost 2 times. Its maximum amount is typical for the upper horizon A. The bottom of the Ziz content is Zn, but the decline is weak.

Co-cobalt. It is established that cobalt has a positive effect on the growth and development of plants and ensures the ability of leguminous crops to capture molecular nitrogen from atmospheric air. In addition, cobalt is part of provitamin B12, which is formed in plants and is necessary for animals and humans. It is established that if the cobalt concentration is reduced to 0.1mg/kg of dry matter and lower, the use of cobalt fertilizers gives a positive result. Co deficiency in soils can cause carbonate, alkalinity, including podzolization and solubility, as well as a high content of humus, iron oxides and manganese. MPC of this element in soils-50mg/ kg, in drinking water-0.1mg/l, in feed-10mg kg of dry matter. In the studied saline agrolandscape (Table 3), no excess of cobalt was found in the soils. In the eluvial positions in the profile of the meadow-chernozem soil, its maximum amount falls on the upper humus horizons A1 and A1-8.5-7.8mg/kg, in the horizon ABdecreases to 5.8, and then its content again slightly increases. On alluvial positions in the profile of meadow-marsh saline soil, the amount of gross Co is almost 2mg/kg falls on the upper horizon of Hell, which can be explained by the movement of Co from upper positions to lower ones with surface and subsurface waters. The cobalt content in the studied soils is significantly lower than the MPC.

Sr-Strontium. Gross strontium is a toxic chemical element for plants and animals. In addition, it can cause a negative effect. For example, iodine in the presence of strontium becomes inaccessible to living organisms in which iodine deficiency begins to develop, with all the negative consequences that follow [21]. Currently, MPCs for strontium have been developed for drinking water up to 2mg/l [16]. For soils, MPCs of strontium have not been established, but according to the studies of Kovalsky VV [21], 600mg/kg should be considered a critical level of strontium content in the soil. The strontium - calcium balance expressed by the Ca/Sr ratio in the most prosperous areas, for example, in the Kursk Region is 200, and in the endemic areas of the Amur Region it decreases to 3.5. According to the data of researchers [8,22,23], the saline soils of the Barabinskaya plain contain high amounts of Sr, which is an antagonist of Ca. The results of our early studies convincingly indicate that the distribution of the total strontium content is characterized by its accumulation in accumulative positions and a decrease in eluvial concentrations [24]. Our data are consistent with the results of previous researchers. From (Table 3) it can be seen that on the eluvial position, the content of strontium in the upper horizon is 233mg/kg. In the AB horizon, it decreases to 131, and in the parent rock again increases to 328 mg/kg. In the accumulative position, its amount increases many times. Maximum-4640mg/kg-accounted for the parent rock. Such amount of Sr indicates its high content in the territory of the saline natural landscape. It was established that the average Ca/Sr ratio in the soils of the Barabinskaya Plain is 26-52. In the area under study, it also fluctuates within the same limits (Table 6). This ratio between Ca/Sr indicates a significant imbalance of their content in the soil and in plants. An increase in strontium concentration in soils is one of the main factors increasing them in plants and then in animals and humans. The optimal balanced ratio of Ca/Sr in feed and food is considered to be 80 [24].

Table 6: Ca/Sr ratio in soils of a saline agrolandscape of the southern part of the Prichanovskaya depression.

Ni-Nickel. The need for this chemical element for the life of living organisms has been recently established [8]. It is indispensable in the composition of urease and is consumed by bacteria of legumes, stimulates the processes of nitrification and mineralization of nitrogen compounds, positively affects the activity of nitrate reductase, which contributes to the recovery of nitrates and nitrogen fixation. In living organisms, nickel is involved in the structural organization of DNA, RNA and proteins [25-26]. In the Novosibirsk region, there is no natural shortage or excess of this chemical element for plants and animals.

The Regulated Nickel Content in the Soils of Russia is as Follows

APC in sandy and sandy soils-20; in loamy and clayey (sour-40); in loamy and clay (neutral)-80mg/kg. MPC for plant products in feed grain-1, in coarse and succulent feeds-3 mg/kg of dry matter. MAC in drinking water in many countries of the world is 0.1mg/l. In the studied saline natural landscape, the nickel content in the soils of the catena under consideration is significantly lower than the established JDC. At the eluvial position in the meadow-chernozem soil, the nickel content is more or less evenly distributed over the genetic horizons, while at the accumulative position its content increases almost twice, especially in the upper horizon of the hell meadow-marsh saline soil up to 70mg/kg, gradually decreasing with depth, reaching 49mg/kg in the C horizon. The obtained data convincingly indicate that nickel is easily washed away by surface waters from the soil profile of the upper landscape positions to the lower ones and accumulates in the upper soil horizons.

Conclusion

a) A profile study of the macro-and microelement chemical composition of soils was carried out in one of the EPA of a saline agrolandscape in the southern part of the Prichanovskaya depression by catena, in which eluvial (upper) and accumulative (lower) positions were distinguished. At the top position, the soil is represented by a meadow - chernozem plain poorly malignant, and at the bottom - by a meadow – marsh salt marsh.

b) The study of the content of Si, Fe, Al, Ca, Mg, Na, and P macronutrients showed that silicon prevails in both eluvial and accumulative positions, but its eluvial positions are 2 times higher than in accumulative ones. In both soils, the Ca content predominates over the Mg content, especially in the carbonate horizons of the lower position, where conditions are created for its accumulation in a biogenic way. The Na content in the upper horizons of the meadow-chernozem soil exceeds the Ca content.

c) Mg and slightly less than in the hell and A horizons of the meadow-marsh soil due to the periodic flushing of these horizons.

d) In the lower positions of the salted agrolandscape, more microelements accumulate (2-3 times or more) than in the upper positions due to their movement with surface and groundwater. Basically, their content is below the established MPC, which indicates the absence of natural pollution by them. The exceptions are trace elements-arsenic, barium, bromine, and strontium, whose content is several times higher than the MPC. Especially dangerous for animals and humans is the low Ca/Sr ratio in the soils of this region, both in eluvial (23-103) and accumulative (21-39) positions at a rate of 200. Therefore, it is necessary to take measures to increase the Ca content or decrease Sr in soils.

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annieboltonworld · 5 years ago

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Juniper Publishers- Open Access Journal of Environmental Sciences & Natural Resources

Influence of Different Land Use Types and Soil Depths on Selected Soil Properties Related to Soil Fertility in Warandhab Area, Horo Guduru Wallaga Zone, Oromiya, Ethiopia

Authored by Tarekegn Fite

Abstract

Background: Inappropriate land use system in Ethiopia, leads to extensive deforestation which exacerbates soil erosion and other soil degradation.

Methods and Materials: The study was conducted at Warandhab area, Jimma Rare District, Wallaga Zone, Oromiya Region, with the objective to identify the influence of different land use types and soil depths on selected soil physical and chemical properties related to soil fertility.

Results: Soil physical properties, pH, SOM, total nitrogen, available P, exchangeable Mg, K, Na, CEC and micronutrients observed were significantly affected (P ≤0.05) by land use. All land use types were clayey but clay loam for forest land. The highest and lowest mean BD was obtained in subsurface of cultivated and surface layer of grazing land respectively. The highest soil water content at FC and AWHC and lowest was recorded in subsurface and surface of forest and cultivated land, respectively. The highest pH = 6.47 and lowest pH = 5.29, were obtained in subsurface of grass land and surface layers of cultivated land, respectively. The range of pH in surface and subsurface layers of all and use types were strongly acidic to slightly acidic. The higher (16.00, 20.04, 89.03, 2.49, 3.39) mg/kg available P, Fe, Mn, Zn, Cu, respectively and CEC (32.80 cmol(+)/kg) were recorded in surface layer of cultivated land than in subsurface. Values of exchangeable bases (Na, K, Ca and Mg) were lower on surface of cultivated land than subsurface of forest land, respectively.

Conclusion: The inappropriate land use management led to disturbance of soil nutrient status, indicating that the soil condition in the cultivated land is getting below the condition of soils under forest and grazing lands. Therefore, reducing intensity of cultivation, adopting integrated soil fertility management and application of organic fertilizers could maintain the existing soil condition and replenish degraded soil properties.

Keywords : Land use types; Soil depths; Soil fertility; Soil productivity; Soil physical properties; Soil chemical properties; Micronutrients; Soil Organic Matters; Grass land; Cultivated land

Abbreviations: SOM: Soil Organic Matter; GPS: Global Positioning System; GIS: Geographical Information System

Introduction

With the rapid growth of African population, soil fertility is a major concern of the world, including Ethiopia which is the second populous African country. High quality soils not only produce better food and fiber, but also help to establish natural ecosystems and enhance air and water quality [1]. Soil fertility changes and the nutrient balances are taken as key indicators of soil quality [2]. It is well known that in traditional farming systems, farmers use bush fallow, plant residues, household refuse, animal manures and other organic nutrient sources to maintain soil fertility and soil organic matter. Soil fertility varies spatially from field to larger region scale, and is influenced by both land use and soil management practices [3]. Revealing spatial variability of soil fertility and its influencing factors are important to improve sustainable land use strategies [4]. It is reported that differences in fertilization, cropping system and farming practices were the main factors influencing soil fertility quality at field scale [5].

The physical conditions and variations in altitude have resulted in a great diversity of climate, soil and vegetation Asrat [6] which constitutes the high mountains, deep gorges, flat- topped plateaus, and rolling plains of Ethiopian topographical feature. Due to such typical feature and cultivation pattern such as on steep and fragile soils with inadequate investments in soil conservation, erratic and erosive rainfall patterns, declining use of fallowing, limited recycling of dung and crop residues to the soil, limited application of external sources of plant nutrients, deforestation and overgrazing Belay [7] and Hurni [8] were the main causes of land degradation in Ethiopia. Inappropriate use of land, mainly characterized by extensive deforestation and conversion into agricultural land, is the most widespread change in land use in Ethiopia [9,10]. All these contribute to the change in chemistry, biology and hydraulics of the soil.

Smith et at. [11] reported that deforestation and cultivation of the same land as the main cause of changes in soil pH and acidifications. Although soil organic matter (SOM) are crucial in regulating the supply of plant nutrients, water flow and determines the physical properties of the soil Cotrufo et al. [12], its altered by soil managements and types, land uses systems and types and the climate [13-15]. As reported by Genxu et al. [16] the availability and distributions of P in soil profile is determined by the different land use types, management practices such as level of SOM, biomass production in the soil, vegetation cover and nutrient cycling in the ecosystems. In another study, in the sub-humid highlands of South-western Ethiopia, shift of land use changes from natural forest to cultivation led to depletion of P [9]. Because of the study area are facing agricultural challenges such as shortage of land for crop cultivation and livestock grazing, decline of soil fertility and rainfall variability resulting in low yield production, determining the soil property is crucial for further soil management and improvement. Therefore, this study was initiated with the objective to investigate the influence of different land use types and soil depths on selected soil physical, chemical properties and organic matter in Warandhab areas of Jimma Rare District.

Materials and Methods

Description of the Study Area

The study was conducted at Warandhab area in Jimma Rare District, Horo Guduru Wallaga Zone, Oromiya Regional State. It is about 255 km away from the capital, Addis Ababa, and located in the mid-west of Ethiopia and 10 km away from the district town, Wayu, to the west. Geographically, it is located between 9o 13' 26” to 9o 15' 58” north latitude, and 37o 15' 14” to 37o 16' 02” east longitude with an elevation ranging 2224-2243 metres above sea level (Figure 1). It covers an area of about 800 hectares and shares commonly with Dile Kolba Peasant Association to the west, Biqiltu Babala and GudataDobi PA in the east, Bada Warqe PA in the south and swamp/marsh area in the north. Jimma Rare District shares boundaries in the west with Jimma Ganati and BakoTibe Districts, in the north with Guduru District, in the south and east with Caliya District. This district possesses a total area of 340.78 km2 (Figure 1).

Climate

The average weather data recorded at the weather station located at Wayu town near the study area from the year 20042010 indicates that the study area has a uni-modal rainfall pattern with mean annual rainfall of 1530.9 mm. The rainy season covers the period from mid-April to October and the maximum rain is received in the months of June, July and August (Figure 2). The annual mean minimum and maximum and the annual average air temperature for the year 2010 are 11.5, 23.8, and 17.625 0C, respectively (Figure 2).

Site Selection, Soil Sampling and Preparation

Planning, surveying and appropriate sampling are important considerations when attempting to measure changes in surface soil chemical and physical properties to accommodate spatial variation. Primarily, a general visual field survey of the area was carried out to have a general view of the variations in the study area. Representative soil sampling site were then selected based on vegetation cover and cultivation history. Following this, three representative land uses (cultivated, forest and grass lands) were selected and Global Positioning System (GPS) and clinometers were used to identify the geographical locations and slopes of the sampling sites, respectively. Using Geographical Information System (GIS) and geographical coordinates for each sampling site, the sampling site was sketched. Composite soil samples were collected from the depths of 0-20 and 2040 cm. Each composite soil samples was made from 5-10 subsamples collected from within the respective area delineated as a replication of such land use. Dead plants, furrow, old manures, wet spots, areas near trees and compost pits were excluded during collection of samples. This was minimizing differences, which may arise because of the dilution of SOM due to mixing through cultivation and other factors.

The soil samples collected from representative land uses with its replications were then air-dried, mixed well and passed through a 2 mm sieve for the analysis of selected soil physical and chemical properties. Separate soil core samples from the 0-20 and 20-40 cm depths were taken with a sharp-edged steel cylinder forced manually into the soil for bulk density determination. To make one composite soil sample the subsamples were mixed well and about 1 kg of the mixed subsamples was properly labeled. Finally eighteen total composite soil samples were prepared and packed in a plastic bowl, and transported to Soil Testing Centre for further analysis.

Analysis of Soil Properties

Soil texture was determined by the Bouyoucos hydrometer method after destroying organic matter and dispersing the soil by using sodium hexametaphosphate as described by [17]. Bulk density was determined from undisturbed soil samples by the core method after drying a defined volume of soil in an oven at 105 °C to constant weight [18]. It was calculated as the ratio of mass of oven dried soil to the volume of the sampling core. The soil water content at PWP and FC was determined after soils were subjected to required pressures (15 and 1/3 bars, respectively) by the pressure plate apparatus. Soil pH (H2O) and pH (KCl) were measured by using a pH meter in a 1:2.5 soil: water and soil: KCl ratios, respectively [19]. Soil organic carbon was estimated by the Walkley-Black wet oxidation method and converted to organic matter by multiplying the percent organic carbon content by a factor of 1.724, assuming that organic matter is composed of 58% carbon [20].

Total nitrogen was determined by the micro-Kjeldahl digestion, distillation and titration method Sahlemedhin and Taye [21] and available P was determined using the standard Olsen extraction method [22]. Total exchangeable bases were determined after leaching the soils with ammonium acetate [23]. Amounts of Ca2+ and Mg2+ in the leachate were analyzed by atomic absorption spectrophotometer and K+ and Na+ were analyzed by flame photometer. Cation exchange capacity was determined at soil pH level of 7 after displacement by using 1N ammonium acetate method in which it was estimated titrimeterically by distillation of ammonium that was displaced by sodium [24]. Percent base saturation was calculated by dividing the sum of the base forming cations (Ca, Mg, Na, and K) by the CEC of the soil and multiplying by 100. Total exchangeable acidity was determined by saturating the soil samples with potassium chloride solution and titrated with sodium hydroxide as described by [25]. Extractable micronutrients (Fe, Cu, Zn, and Mn) were extracted by diethylene triamine penta acetic acid (DTPA) as described in [21]. Finally, the amounts of all these micronutrients were measured by atomic absorption spectrophotometer at their respective wave lengths.

Statistical Analysis

The general linear model (GLM) ANOVA procedure of statistical analysis system SAS [26] was used for performing the significance of differences in soli parameters. A post hoc separation of means was done by least significant difference (LSD) test after main effects was found significant at P ≤0.05. The analysis was performing for each land use types (cultivated, grass and forest lands) in six combined treatments.

Results and Discussion

Soil Physical Properties

Soil texture

The sand and clay fractions were significantly (P ≤ 0.01) affected by the interaction of land use and soil depth. Similarly, the silt fraction was significantly (P≤ 0.01) affected by land use and soil depth (Table 1). Considering the interaction effects of land use and soil depth, the highest (51%) sand and (31%) silt contents were recorded at the surface layer of forest land than cultivated land. In contrast, the highest (58%) clay content was recorded at the subsurface layer of the cultivated land, whereas the lowest (18.00) clay content was observed in the surface layer of the forest land (Table 1). The current result is in agreement with the findings of Shiferaw [27] who reported an increase in clay content with depth under cultivated lands due to long period of cultivation.

In a similar way Boke [28]; Alemayehu and Sheleme [29] reported that high sand content in grass land soils in Southern Ethiopia. Buol [30] also observed that the accumulation of clay in the subsurface horizon could also be contributed by the in situ synthesis of secondary clays or the residual concentration of clays from the selective dissolution of more soluble minerals of coarser grain size in the B horizon. Agoume and Birang [31] similarly found that land-use systems and soil depths significantly affected the sand, the clay and the silt fractions of the soils size distributions in Cameroon and even by land use alone Jaiyeoba, VoundiN, kana and Tonye [32-36] reported that continuous cropping and intensive land use affected the particle size distribution and that these changes related to cultivation time, but the current finding is in contradict to the result reported by Shepherd et al. [35] who found that land use systems were no effect on soil particles. Sand and silt content decrease while clay content increases across depth from surface to subsurface soils. The increase in clay contents with depth under all land use types may be due to translocation of clay from surface to subsurface layers, which ultimately increase the proportion of sand and silt contents in the surface soil layers.

Soil water characteristics

Water retention at both FC and PWP was significantly affected by main effects (P ≤0.01) and their interaction (Table 1). Moreover, AWHC was significantly (P ≤ 0.01) affected by land use and soil depth but not significantly (P > 0.05) affected by their interactions (Table 1). Significant difference in FC and PWP due to the interaction of land use and soil depth as observed in the study area was high at subsurface layers of the forest and cultivated lands and low at the surface layers of the cultivated and grass lands, respectively (Table 2). On the other hand, the highest (17.98%) and the lowest (9.67%) AWHC among the land use types was obtained in the forest and cultivated lands, respectively. The soil water content at FC, PWP and AWHC increased with soil depth (Table 2). The result of this study is in agreement with Wakene [37] and Ahmed [38] who reported that soil water content at FC, PWP and AWHC were found to increase with depth for soils under different management practice. As per AWHC rating developed by Beernaert [39], the AWHC of the surface soils of the study area was in the range of low in cultivated land to medium in forest land (Table 2). Moreover, various studies also examined the effects of land use and land cover change on soil physico-chemical properties [31, 32,39-41]. *Main effect means within a column followed by the same letter are not significantly different from each other at p ≤ 0.05 LSD = least significant difference; SEM = standard error of the mean; BD = bulk density; FC = field capacity; PWP = permanent wilting point; AWHC = available water holding capacity.

Bulk density value was significantly (P ≤ 0.05) affected by land use types (Table 2). The highest (1.41 g/cm3) mean value of bulk density was recorded on the cultivated land and the lowest (1.11 g/cm3) mean value under the grass land (Table 2).

Compaction resulting from intensive cultivation might have caused the relatively higher bulk density values in the surface soil layers of the cultivated land than that of the respective soil depths in the grass land. Liu [5] and Celik, [36] reported that land use and soil management practices influence the soil nutrients and related soil processes, such as erosion, oxidation, mineralization and leaching etc. Moreover, in non-cultivated land, the type of vegetative cover is a factor influencing the soil organic carbon content as reported by Liu et al. [5]. Land use change also produces considerable alterations Fu et al. [42] and usually soil quality diminishes after the cultivation of previously untilled soils [38]. The reason for the relatively low soil bulk density on the grass and forest lands as well as surface soil layer could be due to the highest SOM content and low clay content, respectively. Similarly, Gol [43] also investigated the effects of land use change on soil properties and organic carbon at Dagdami river catchment in Turkey and bulk density as affected by land use in Ethiopia [40]. *Main effect means within a column followed by the same letter are not significantly different from each other at p ≤ 0.05; NS = not significant; STC = soil texture class; c = Clay; cl = Clay loam; BD = Bulk density; FC = Field capacity; PWP = Permanent wilting point; AWHC = Available water holding capacity; LSD = least significant difference; SEM = Standard error of the mean; CV = Coefficient of variation.

Soil Chemical Properties

Soil pH values measured in a suspension of soil to water ratio are greater than that of in soil to KCl solution ratio. The pH (H2O) value of the soils content was significantly (P ≤ 0.01) affected by all land use types and their interaction effects (Table 3). The highest (6.47) and the lowest (5.29) soil pH-H2O values were recorded under the grass and the cultivated lands at 2040cm and 0-20cm soil depths, respectively (Table 3). Continuous cultivation practices, excessive precipitation, and application of inorganic fertilizers could be some of the factors which are responsible for the variation in pH in the soil profiles [42-45]. In line with the findings of this study, soil pH increased with depth of soil profile and relatively high pH was observed at subsoil horizons in Alfisols of Bako area Wakene [37] and in Vertisols of the central highlands of Ethiopia [46]. Agoume and Birang [31] also reported that pH of the soil as affected by land use system of an Oxisol in the Humid Forest zone of the Southern Cameroon. In other study conducted by Nega and Heluf [47] they found that pH the soil was affected by the interactions of land use changes and the soil depths in Western Ethiopia. Alemayehu and Sheleme [29] also found an increment of soil pH at two depths (0-15 and 15-30cm) under enset cultivations and. Generally, the pH (H2O) values observed in the study area were within the ranges of moderately acidic to slightly acidic (5.50-6.23) and pH (KCl) values ranged from very strongly acidic to strongly acidic (4.305.21) soil reactions as classifications indicated by Brady and Weil [48].

Soil organic matter/SOM content was significantly (P ≤ 0.01) affected by the interaction of land use type with soil depth (Table 3). The interaction effect of land use by soil depth, on the variability of SOM was significantly higher (8.37%) at surface layer of the forest land and lower (1.83%) at subsurface layer of cultivated land (Table 3). The reason may be due to intensive cultivation of the land and the total removal of crop residues for animal feed and source of energy. Based on the distribution of SOM ranges suggested by Berhanu [49], the soils of the study area were ranged from medium in cultivated land to very high in forest land. Urioste et al. [50] suggests thatroots of the grass and fungial hyphae are probably responsible for the high amount of total organic matter in grassland. This result is in agreement with Eylachew [51,52] and who reported that SOM content under grazing and cultivated soils were lower than those under natural vegetation's/forest. Malo et al. [53]; Nega and Heluf [47] also reported less organic carbon in the cultivated soils than grassed soils and high in the surface soils of forest land while least were from subsurface layers of the cultivated soils, respectively.

Total nitrogen content of soils was significantly (P ≤ 0.01) affected the interaction of land use by soil depth (Table 3). On the other hand, carbon to nitrogen (C/N) ratio of the soils at the study area was significantly affected by the interaction of land use with soil depth (P ≤ 0.01). On the other hand, it was not significantly (P > 0.05) affected by soil depth (Table 3). The effect of land use by soil depth on total N was significantly higher (0.42%) at the surface layer of the forest land than (0.09%) in the subsurface layer of the cultivated land (Table 3). The mean total N content of the surface soils of the study area was within the range of low in soils of cultivated land to very high in soils of forest land as per total N rating suggested by Berhanu [49,47]. The very high total N content in soils of the forest land could be associated with the high available P and CEC contents of these soils. In their study,Alemayehu and Sheleme [29] also found higher total nitrogen in grassland fields followed by that of enset at 0-15 and 15-30cm soil depths. Moreover, this study was in agreement with Ukaegbu and Akamigbo [54]; Agoume and Birang [31] and Iwara et al. [55] they found that total nitrogen as affected by land use systems.

Carbon to nitrogen ratio of the subsurface layer of the cultivated land was significantly higher (11.65) than those under forest and grazing lands at 20-40cm soil depths (Table 3). The C/N ratios were numerically high in the subsurface than surface soil layers. Our current result contradicts the finding of Nega and Heluf [47] who found that land uses did not variant in C/N ratio but these ratios varied across soil depth. Yihenew [56] indicated that the optimum range of the C/N ratio is about 10:1 to 12:1 that provides nitrogen in excess of microbial needs. Accordingly, the C/N ratio of the soil across the study area may be considered to be within the optimum range in all land use types and soil depth. *Main effect means within a column followed by the same letter are not significantly different from each other at p < 0.05 LSD = least significant difference; SEM = standard error of the mean; SOM = soil organic matter; total N = total nitrogen; C/N = carbon to nitrogen ratio; AvP = available phosphorus; EA = exchangeable acidity.

Available Phosphorus

The available phosphorus (P) was significantly (P ≤ 0.01) affected by the interaction of the two factors (Table 3 and Appendix I). The content of available P in the cultivated land appeared to be significantly higher than the other two land use types. The higher in available P contents in soils of cultivated land were due to continuous application of mineral P fertilizer for few years as indicated by different farmers in the area. Van der Eijk et al. [57] have also reported that the high content of P under maize farms than of grass land soils could be due to the continuous application of phosphorus fertilizer applications. Similarly, Boke [28] also found that high availability of P under enset farms which is due to rapid mineralization and additions of manure and crop residue. Accordingly, by considering the interaction effect of land use with soil depth, the highest (16.00 mg kg-1) and the lowest (1.67 mg kg-1) available P contents were recorded at the surface soil layer of the cultivated and subsurface soil layer of the grass lands, respectively (Table 3). This result is in agreement with the findings reported by Nega and Heluf [47]; Ekukinam [58]; Alemayehu and Sheleme [29] that soil available P was significantly affected by land use types. The mean available P content of the soils of the study area was within the range of low in soils of grass land to high in soils of cultivated land as per available P rating suggested by [22].

Exchangeable Acidity and Basicity

The exchangeable acidity was not significantly (P >0.05) affected by land use and soil depth interaction (Table 3). Considering the absolute figures, relatively higher EA was recorded in soils of the cultivated land as compared to the other land use types (Table 3). These results show that intensive cultivation and application of inorganic fertilizers leads to the higher exchangeable acidity content under the crop field than the other land uses.

The content of exchangeable calcium (Ca) was not significantly (P > 0.05) affected by the interaction of land use with soil depth (Table 4). Based on the data obtained in the study area, relatively higher exchangeable Ca was recorded in subsurface soil layer of the forest land as compared to the other land use types and their depths (Table 4). According to the rating set by Landon [59], the Ca contents of soils in the study area ranged from high in surface cultivated land to very high in subsurface forest land (Table 4). The present study was in contradicted with Agoume and Birang [31]; Iwaraet al. [55]; Gebeyaw [32] who reported exchangeable calcium (Ca) was significantly affected by land use systems. However, Alemayehu and Sheleme [29] found higher Ca exchangeable under enset field at 0-15cm soil depths.

Exchangeable K content was significantly (P ≤ 0.01) affected by the interaction of land use and soil depth (Table 4). Considering the interaction effects of land use by soil depth, the highest (2.15 cmol(+)/kg) and the lowest (0.77 cmol(+)/ kg) exchangeable K contents were recorded at the subsurface layers of the forest land and the surface layers of the cultivated land, respectively (Table 4). The low exchangeable K contents observed under cultivated land could probably due to continuous cultivations and inorganic farming practices in the study area which is supported by previous findings that indicate intensity of weathering, cultivation and use of acid forming inorganic fertilizers affect the distribution of K in the soil system and enhance its depletion [53].

The concentration of exchangeable potassium (K) followed trend of being enset field > grass land >maize farms for the three land uses and depths (0-15 and 15-30cm) and highest cation exchange capacity (CEC) under grassland [29].With the exceptions of the surface layers of the forest land and the subsurface layer of the grass lands, the mean exchangeable K contents of the remaining treatment combinations were significantly different (P≤ 0.05) from each other due to the interaction effects. The rate of mean exchangeable K values observed in this study ranged from high in cultivated land to very high in forest land Wang et, al. [60,61] (Table 4). Urioste et al. [50] reported that, the addition of organic matter increases the amount of exchangeable cations bases and the low cations bases in cultivated fields are due to the intensive cultivations and continues use of inorganic fertilizers which enhances the loss of base cations through erosion, crop harvest and leaching [62].

The content of exchangeable Na was significantly (P ≤0.01) affected by the interaction of land use by soil depth (Table 4). The effects of land use by soil depth on exchangeable Na was significantly high (0.25 cmol(+)/kg) under subsoil layer of the forest land and low (0.13 cmol(+)/kg) under surface soil layer of the cultivated land (Table 4). According to the rating set by Landon [59], the Na contents of soils in the study area is low. Alemayehu and Sheleme [29] reported higher exchangeable Na exists in the 15-30cm depth in grassland soils under enset field.The increase in basic cations concentration as well as percent base saturation with depth may suggest the existence of downward movement of these constituents exchangeable Ca, Mg, Na and K within the profile. Generally, the lower available exchangeable Na cation under cultivated land is an indicative for the depletion of the surface soils of the study area. Moreover, Negassa [62] reported that intensive cultivation and continuous use of inorganic fertilizers in the cultivated fields that will enhance loss of base cations through leaching, erosion and crop harvest.

Cation Exchange Capacity

The CEC values of the soils in the study area were significantly (P ≤ 0.01) affected by the interaction of land use with soil depth (Table 4). Significant difference in CEC contents due to the interaction of land use and soil depth was observed in the study area as highest (39.00 cmol+/kg) in surface soil layer of the grass land and lowest (23.87 cmol+/kg) in subsurface soil layer of the cultivated land. CEC values decreased from the surface to the subsurface layer under different land use types (Table 4). Based on CEC ratings developed by Landon [59], the CEC content of soils of the study area was rated as high in their CEC. It was generally low in the cultivated land than in the other land use types (Table 4). As indicated by Mesfin [63]; Negassa [62]; Boke [28] the depletion of exchangeable bases as the result of intensive cultivation and application of acid forming inorganic fertilizers which reduced the CEC under the cultivated land. Reid and Dirou [64] reported that oils with large amounts of clay or OM have higher exchange capacities than sandy soils, which are usually low in organic matter. Alemayehu and Sheleme [29]; Wasihun et al. [40] also reported high cation exchange capacity (CEC) values under grassland and grazing land compared to cultivated land respectively.

Exchangeable magnesium (Mg) was significantly (P ≤ 0.01) affected by land use, but not significantly (P > 0.05) affected by soil depth and the interaction of land use with soil depth. The mean values of exchangeable magnesium (Mg) was higher (8.51 cmol(+)/kg) under the forest land and lower (3.62 cmol+/kg) under the cultivated land. As per exchangeable Mg rating set by Landon [59], the Mg contents of soils in the study area was in the range of high in cultivated land to very high in forest land (Table 5). The result of study was in agreement with those reported by Wakene [41], who reported that inorganic fertilizer application is the root cause of soil acidity. In addition, Wang et, al. [60]; Iwara et al. [55] also indicated that climate and geological history are the main important factors affecting soil properties.

Extractable micronutrients (Fe, Mn, Zn and Cu)

The contents of extractable micronutrients (Zn, Mn and Cu) were significantly (P ≤ 0.01) affected by the interaction of land use by soil depth (Table 6), while Fe was significantly (P ≤ 0.01) affected by land use and soil depth, but not significantly (P > 0.05) affected by the interaction of land use with soil depth (Table 7). As to the ratings of Sims and Johnson the critical level of soil available (DTPA extractable) Fe, Cu, and Mn are 2.5-4.5, 0.1-2.5 and 1-50 mg/kg, respectively. Therefore, the soil contents of extractable micronutrients in all land use types with depth were above the critical levels indicating that there is no deficiency of these micronutrients in the study area (Table 6). According to the report of Alemayehu and Sheleme [29]; Wasihun et al. [40] in that micronutrient status was significantly influenced by different land use systems and soil depth. Accordingly, the contents of all these micronutrients were higher at the surface (0-20 cm) layer than in the subsoil layer of all land use types (Tables 6 & 7). This is due to the lower contents of exchangeable bases in the surface layer which is decreased as the result of leaching. In study conducted by Wasihun et al. [40] at Itang-Kir Area of Gambella Region, Ethiopia, higher extractable micronutrient cations (Fe, Mn, Zn and Cu) were available in grazing land use compared to cultivated land. Laiho et al. [65] also studied the variability in extractable micronutrient (Fe, Mn and Zn) within floristically defined peat land sites. Considering the main effects of land use, the highest contents of Fe (19.74mg/kg), Mn (84.04 mg/kg), Zn (1.87 mg/kg), and Cu (3.03 mg/kg) were recorded under the cultivated land, while the lowest Fe (15.53mg/kg), Mn (47.55 mg/kg), Zn (1.38 mg/kg), and Cu (1.51 mg/kg) were observed under the grass land (Table 7). *Main effect means within a column followed by the same letter are not significantly different from each other at p ≤ 0.05 LSD = least significant difference; SEM = standard error of the mean; CV = coefficient of variation.

Conclusion

The result of this finding suggests that the textural class of cultivated and grass land were clayey, whereas it was clay loam for forest land. The mean bulk density value of cultivated land was significantly greater than the value in the forest and grass land. Soil water content were highly significantly affected by land use and soil depth whereas the mean exchangeable Mg and K content of the soil were highly significantly affected by land use but not by soil depth. On the other hand, Ca was not affected by both land use and soil depth. The mean value of exchangeable Na, K, Ca and Mg were relatively lower in the surface and higher in the subsurface soil layers of cultivated and forest lands, respectively. The value of exchangeable bases relatively increases with soil depth. The mean CEC content of the soil were highly significantly affected by both land use and soil depth. However, it was greater in the surface grass land and lower in subsurface cultivated land. The values of available Fe, Zn and Cu observed were highly significantly affected by land use and soil depth while the mean value of available Mn was highly significantly affected by land use but not with soil depth.

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literaturepublishersjournal · 2 years ago

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Toxicity Case Reports Journal

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juniperpublishers-agriculture · 6 years ago

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Environmental Ethics: The Virtuous Way | Juniper Publishers

Environmental ethics, among other things, is concerned with our attitude toward nature. By nature here I don’t mean anything other than the waters, the trees, non-human animals-the environment. It is, moreover, concerned about what Rosalind Hurst house call “the belief that a fairly radical change in the way we engage with nature is imperative.” In what follows, I want to propose a virtue-oriented approach to environmental. My aim is to begin a discussion about the potential advantages of adopting a virtue-based approach to our outlook toward the environment.

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irispublishersagriculture · 4 years ago

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Iris Publishers - World Journal of Agriculture and Soil Science (WJASS)

Determinants of Savings Capacity among Agribusiness Entrepreneurs in Yobe State, Nigeria

Authored by Okpachu SA

Traditionally, agriculture is seen as a low-tech industry with limited dynamics dominated by numerous small family firms which are mostly focused on doing things better rather than doing new things. Over the last decade, this situation has changed dramatically due to economic liberalization, a reduced protection of agricultural markets, and a fast changing, more critical, society. Agricultural companies increasingly have to adapt to the vagaries of the market, changing consumer habits, enhanced environmental regulations, new requirements for product quality, chain management, food safety, sustainability, and so on. These changes have cleared the way for new entrants, innovation, and portfolio entrepreneurship. It is recognized by all and sundry that farmers increasingly require entrepreneurship, besides sound management and craftsmanship, to be sustainable in the future [1].

Over the past 30 years, there has been a major shift in agricultural markets and the international trade of agricultural products. The world is moving from local and national markets towards a global system of trading, which means that neighboring farmers working on small plots of land may be competing with large industrial farmers from another country in a single marketplace. In developing countries, there is increasing pressure on farmers to commercialize their operations. This change is driven by the following factors:

• Declining land size, which means that farmers need more intensive production systems to support their family needs;

• Urbanization and rapid population growth and

• General modernization, which means that farming families need to generate larger incomes to support their family needs and expectations in terms of medical support, education, transport, communication and to cover the rising costs of their cultural traditions.

In order to meet the drive for greater commercialization, extensionists need to develop new skills to support the agripreneur needs of farmers and other actors in the value chain. For the farmer, this includes working with individual farmers to develop farm plans, as well as working with various levels of farmer organizations— from groups to cooperatives—in areas of market analysis, financing, sales and building business opportunities for farming clientele.

Entrepreneurship, value chains and market linkages are terms that are being used more and more when talking about agriculture and farming. Many small-scale farmers and extension organizations understand that there is little future for farmers unless they become more entrepreneurial in the way they run their farms. They must increasingly produce for markets and for profits. A farmer-entrepreneur is someone who produces for the market. A farmer-entrepreneur is a determined and creative leader, always looking for opportunities to improve and expand his agribusiness. A farmer-entrepreneur likes to take calculated risks and assumes responsibility for both profits and losses. A farmer-entrepreneur is passionate about growing his business and is constantly looking for new opportunities. Farmer-entrepreneurs are also innovators, who always look for better and more efficient and profitable ways to do things. Being innovative is an important quality for a farmer-entrepreneur, especially when the business faces strong competition or operates in a rapidly changing environment.

In most recent times, the emphasis on agri-food chain coordination, value creation and the institutional setting under which chains operate, have significantly increased the importance of the agribusiness sector. However, the scenario appears different in Nigeria due to neglect and perceived under development of the agribusiness sector, which has retarded poverty alleviation in the country.

Capital accumulation and savings are regarded as the engine of growth in any country. Unfortunately, the relative poverty of the rural agribusiness entrepreneurs in Nigeria hampers savings and investment potentials and this together with the poor attention from the government have continued to perpetuate low growth and productivity in the food and agricultural sector of the country.

Sustainable growth in any sector of an economy is a function of capital accumulation and increased savings. Unfortunately, the relative poverty of the rural agribusiness entrepreneurs in Nigeria hampers savings and investment potentials which retard growth and productivity in the food and agricultural sector of the economy. Leads to Savings to a large extent determine the growth rate of the productive capacity and output. It is the views of Egwu & Nwibo [2], that the lack of access to productive resources and low returns to agricultural production as well as the bureaucracy involved in opening bank account are some of the limitations to the saving capacity of agribusiness entrepreneurs. In a bid to save, some of these entrepreneurs prefer to loan out their cash after sales to reap interest, invest in livestock, store their produce after harvest when prices are low and sell during lean period when prices will rise.

Having recognized the importance of savings in the growth and development of an economy, it becomes imperative to look at the determinants of savings capacity of agribusiness entrepreneurs in the country in an effort to develop the food and agricultural sector. The understanding of these determinants will spur innovative decisions from stakeholders in the country responsible for agribusiness development to come up with strategies that will improve the sector’s performance.

The main objective of this study was to examine the determinants of savings capacity among agribusiness entrepreneurs in Benue State. The specific objectives were to describe the types of savings prevalent among agribusiness entrepreneurs; and to identify and analyze the determinants of savings decision among agribusiness entrepreneurs.

Theoretical Framework

The theoretical framework for this study is the collective Entrepreneurship Theory. Collective Entrepreneurship has emerged as a new concept in the literatures of economics, management and entrepreneurship [3]. It emerged as a strategy to accrue economic benefits and improved market access [4]. Steward [5] was the first person to put forward the concept of collective entrepreneurship based on the result of his ethnographic research on high-performing work team. While Stewart [5] is recognized for coining the concept of collective entrepreneurship he didn’t relate the concept to the field of agriculture. Pal [6] were the first to relate collective entrepreneurship to agriculture, focusing on agricultural cooperatives. They defined collective entrepreneurship as a form of rent-seeking behavior exhibited by formal groups of individual agricultural producers that combine the institutional frameworks of investor-driven shareholder firms and patron-driven forms of collective action. Further, Pal [6] point out that for any form of a collective organization to achieve the highest performance, members’ decisions about their own on-farm activities and investments should be aligned with the cooperative. They posited that this is the risk associated with collective entrepreneurship that producers should be willing to take.

Farmer organizations or farmer groups to which collective entrepreneurship applies are common in Africa. By 2005, farmer organizations in Africa had grown to 70 (FANRPAN, 2005). The growth of farmer organizations in Africa emanated from proactive response to be successful in pursuit of significant growth in a rapidly changing economic, social and political environment [7]. Farmer organizations help solve farmers’ collective action problems, that is, how to procure inputs most efficiently and market their outputs on more favorable terms than they could achieve by themselves [7]. Collective action has the potential to organize smallholder farmers in developing countries in the wake of agricultural market liberalization (Mukindia, 2014).

Although collective entrepreneurship is considered as an appropriate tool for linking smallholder farmers to markets and upgrading their socio-economic status, there are potential problems which can undermine its effectiveness. These include low institutional capacity, inadequate qualified personnel, low entrepreneurship skills, lack of financial resources, lack of market information, lack of communication and participation among members, patronizing the business activity of the groups, control and support, mismanagement, financial scandals and poor governance [8]. Collective entrepreneurship can play an important role for rural development. However, farmer organizations or farmer groups are not always successful, and there is a need to better understand under what conditions of collective entrepreneurship is useful and viable. It is important to study the group entrepreneurial behavior that enable farmers to address market challenges.

Methodology

Study area

The study was conducted in Yobe State is located in the North-Eastern part of Nigeria between latitude 12 °00′N 11 °30′, Longitude12 °N 11.5 °E. Potiskum Local Government Yobe State was created out of the old Borno State in 1991 and has seventeen local government areas. The study covered Potiskum Local Government Area, where Agribusiness entrepreneurs abound in the state such as suppliers of farm equipment, agro-chemicals etc. Also, agribusiness entrepreneurs who are engaged in arable crop production like Maize abound as well as those involved in Maize marketers, Sorghum, etc.

Sampling technique and data collection

The data for the study was collected from the respondents using a structured questionnaire from 200 agribusiness entrepreneurs who are involve in the production and marketing of Maize and Sorghum. The respondents were selected using multistage sampling techniques to capture their determinants of savings

Data analysis

The data collected for the study were analyzed using descriptive statistics such as frequency distribution, percentages to describe the types of savings prevalent among respondents. Following Okeke and Mbanasor [9]. Logit model was used to realize the determinants of savings decision among respondents.

Results and Discussions

Types of savings prevalent among respondents

The distributions of agribusiness entrepreneurs according to their most preferred institutions to save with are presented in Table 1. Analysis of Table 1 shows that majority (53%) of agribusiness entrepreneurs regarded Asusu as their most preferred institution to save their money. The policy of asusu is based on the monthly collection of fixed amounts of money from member contributors and loaning out the money to members on low interest rate (mostly 5%) and higher interest rate to non-members (mostly 10%). At the end of the financial year, both the accrued interest paid, and the principal contributions will be shared among members. Agribusiness entrepreneurs prefer saving with asusu as there are no conventional banks within their locality, provides them with benefits such as loans, meat at the end of the year etc., provides them the opportunity to know one another, perception of asusu as a way of life, their low literacy level, their lack of trust for the bank system, and the ease of operation associated with asusu. This finding was in consonance with Nwibo and Mbam [10], Babani [11] that farmers make use of informal financial sectors to mobilize savings and develop their rural communities because it gives them access to loans that they cannot get from formal financial institutions due to lack of collateral.

Furthermore, Table 1 shows that 40% of agribusiness entrepreneurs saw conventional banks as their second most preferred saving institution The preference of agribusiness entrepreneurs to save in conventional banks can be attributed to the safety and ease of accessibility of their money, and easy transaction between them and their customers which they attach to saving with such banks. This finding is corroborated by Haruna [12] who in a study on the determinants of saving and investment in deprived district capitals in Ghana, reported that people prefer saving in banks to “isusu” groups due to high security, trust and proximity.

The result from Table 1 shows that the least preferred institution by the respondents (64%) to save their money was Microfinance banks. The poor rating of microfinance bank as an institution to save with by agribusiness entrepreneurs can be attributed to the unavailability of such microfinance banks within the locality of these entrepreneurs as well as the popularity of Asusu and commercial banks. This finding is corroborated by Sukhdeve [5] who in a study on informal savings of the poor: prospects for financial inclusion, reported that majority of households park their saving in banks while the remaining save their money in informal ways which offer easy access and convenience.

The Nagelkerke R square value of 0.603 indicates that exist a strong relationship of 60.3% between the predictors and the predictions. The analysis also revealed that none of the independent variables had a standard error (S.E) greater than 2.0 thus confirming the absence of numerical problem such as multicollinearity among the independent variables

The prediction success overall was 83.1% Thus, the independent variables could be characterized as useful predictors distinguishing survey respondents who have deliberately saved part of their earnings from survey respondents who have not deliberately saved part of their earnings.

The relationship between gender and likelihood of savings was Positive and statistically significant at 5%. The positive sign of the coefficient is in consonance with the a priori expectation, implying that if an agribusiness entrepreneur is a male, he is 2.580 times more likely to save part of his earnings [13]. Male agribusiness entrepreneurs often engaged themselves in other income generating activities which increases their income and thus their savings when compare to the female agribusiness entrepreneurs who devote much of their earnings on their families, clothes, and jewelries. This finding agrees with Ayenew [14] who indicated that female heads spends their money on the purchase of jewelry, clothes, and crockery etc which reduces their income and subsequently their savings. However, this finding is at variance with Shitu [15] who revealed that rural women save more than their male counterpart.

The coefficient of household size was significant at 5% and negatively related to savings decision. The negative sign of the coefficient correlates with the a priori expectation, implying that as the household size of agribusiness entrepreneurs increases, they are 0.667 times less likely to save part of their earnings. Large household size implies high dependency ratio and increase in nonfarm business expenses such as hospital bills, children’s school fees, social events or household consumables which translates to low savings among agribusiness entrepreneurs. This finding is affirmed by Ike and Umuedafe [16] who posited that large family size is among the major causes of fewer savings.

The result also revealed a positive savings-income relationship, which was statistically significant at 10%. This implies that as income increases, there is greater probability of saving. This finding is supported by Konig, Silva and Mhlanga [17] who posited that the higher the income, the more revenue the farmer generates from his produce and hence, the more he is encouraged to save part of his earning.

The coefficient of membership of cooperative society was significant at 5% and positively related to savings decision. The positive sign agrees with the a priori expectation, implying that agribusiness entrepreneurs who are members of cooperative society are more likely to save part of their earnings. Cooperatives offer its members the opportunity to increase their monthly income which translates to more savings through the social networking platform it provides to its members.

The coefficient of risk of capital loss was significant at 1% and positively related to savings decision. The positive sign of the coefficient is in consonance with the a priori expectation, implying that the perceived risk of capital loss among agribusiness entrepreneurs will make them more likely to save part of their earnings. Agribusiness entrepreneurs will likely embark upon precautionary savings to provide an emergency cushion in case of a sudden loss of income or an unexpected spike in expenditure. Khan and Hye [3] in a study on the financial sector reforms and household savings in Pakistan corroborated this finding by reporting that greater uncertainty increases savings as risk aversion consumers set aside resources as a precaution against possible adverse changes in income.

The coefficient of working experience was found to be significant at 5% in influencing savings in the study area. This implies that the more experienced a respondent has in agribusiness activity, the higher the likelihood of savings. This is expected because the more experience a respondent has, the better her skills which will earn her more. This could also mean that knowledge gained over time from working experience could make the agribusiness entrepreneur more efficient and therefore more remunerated, that is, it is expected that the agribusiness entrepreneur will accumulate physical assets with long working experience and also save more. This finding agrees with Nwibo & Mbam [10] who in a study on the determinants of savings and investment capacities of farming households in Udi Local Government Area of Enugu State, posited that farmers with long experience in farming tend to have wider experience and are more inclined to saving and investment in agricultural activities whose rate of returns are higher [18].

Conclusion and Recommendations

The result from the study shows that majority of the respondents prefer Asusu as their mode of saving. Also, evidence from the study indicates that the socio-economic characteristics of the agribusiness entrepreneurs significantly influence the probability that they will save.

Based on the findings of the study, the following recommendations were made:

• Policies geared towards improving the savings of agribusiness entrepreneurs should inculcate their socioeconomic characteristics in its formulation to ensure better result.

• With the preference for Asusu, Formal financial institutions should develop a synergy to partner with Asusu in order to mobilize savings among agribusiness entrepreneurs in study area.

• There should be an aggressive campaign geared towards promoting the benefits of savings as well as the dangers of not saving should be encouraged especially in the areas of these entrepreneurs

To read more about this article: https://irispublishers.com/wjass/fulltext/determinants-of-savings-capacity-among-agribusiness-entrepreneurs-in-yobe-state-nigeria.ID.000570.php

Indexing List of Iris Publishers: https://medium.com/@irispublishers/what-is-the-indexing-list-of-iris-publishers-4ace353e4eee

Iris publishers google scholar citations: https://scholar.google.co.in/scholar?hl=en&as_sdt=0%2C5&q=irispublishers&btnG=

#Agriculture and Soil Science #Inter National Agriculture Science #Animal Sciences #Food science #Dairy

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anniekoh · 5 years ago

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I just learned that UCL Press books are all open-access?! These two recent books look great. I’m including a snippet of a book review below as I’ve been thinking about book reviews of late (having written two this year).

Mapping Society: The Spatial Dimensions of Social Cartography Laura Vaughan (2018)

From a rare map of yellow fever in eighteenth-century New York, to Charles Booth’s famous maps of poverty in nineteenth-century London, an Italian racial zoning map of early twentieth-century Asmara, to a map of wealth disparities in the banlieues of twenty-first-century Paris, Mapping Society traces the evolution of social cartography over the past two centuries. In this richly illustrated book, Laura Vaughan examines maps of ethnic or religious difference, poverty, and health inequalities, demonstrating how they not only serve as historical records of social enquiry, but also constitute inscriptions of social patterns that have been etched deeply on the surface of cities.

The book covers themes such as the use of visual rhetoric to change public opinion, the evolution of sociology as an academic practice, changing attitudes to physical disorder, and the complexity of segregation as an urban phenomenon. While the focus is on historical maps, the narrative carries the discussion of the spatial dimensions of social cartography forward to the present day, showing how disciplines such as public health, crime science, and urban planning, chart spatial data in their current practice. Containing examples of space syntax analysis alongside full colour maps and photographs, this volume will appeal to all those interested in the long-term forces that shape how people live in cities.

Sustainable Food Systems: The Role of the City Robert Biel (2016)

Faced with a global threat to food security, it is perfectly possible that society will respond, not by a dystopian disintegration, but rather by reasserting co-operative traditions. This book, by a leading expert in urban agriculture, offers a genuine solution to today’s global food crisis. By contributing more to feeding themselves, cities can allow breathing space for the rural sector to convert to more organic sustainable approaches. Biel’s approach connects with current debates about agroecology and food sovereignty, asks key questions, and proposes lines of future research. He suggests that today’s food insecurity – manifested in a regime of wildly fluctuating prices – reflects not just temporary stresses in the existing mode of production, but more profoundly the troubled process of generating a new one. He argues that the solution cannot be implemented at a merely technical or political level: the force of change can only be driven by the kind of social movements which are now daring to challenge the existing unsustainable order.

Review by Rebecca Whittle for the Journal of Political Ecology (v.24)

In the introduction, Biel emphasises that "I approach this topic as a food-growing practitioner and allotment holder: the allotment movement and its working-class traditions of self-organisation continue to inspire me." (p.1). A few paragraphs later, he also signals his intention to engage constructively with the FAO's new focus on 'sustainable intensification' "rather than merely critiquing its 'discourse'."

Both these comments struck a chord with me. Like Biel, I am a social scientist teaching and researching in an interdisciplinary research environment where I want to have a 'constructive engagement' with the plant and soil scientists surrounding me. Like Biel, I am also a practitioner: I have an allotment and help to run a community garden...

And, like Biel, I have frequently wondered why many of the supposed 'alternative' and low-impact forms of growing currently being promoted for environmental reasons – with permaculture and the organics movement being two prime examples – have so little to say about the radical social and political change that is required if we are ever to achieve anything remotely resembling a sustainable food system.

The book's key aim is to bring the more environmentalist/ecological arguments supporting permaculture and other 'alternative'/low impact cultivation systems closer to the social science, Marxist arguments more familiar to political ecologists.

Biel also reminds us of what he describes as the 'paradox of 'innovation' which we see under contemporary agrarian capitalism, i.e., the ways in which many of the apparent 'novelties' being proposed as solutions to these problems (GMOs, biotech innovations and more sophisticated agrochemical formulations to name just a few) actually just result in a deepening of the farming system's dependency on capitalism, alienating us further from nature and exacerbating the social inequalities that result.

...

Here, too, Biel has an important contribution to make. Reminding us that it isn't sufficient to think about agroecology solely as a new mode of production, he explains that:

“…a knowledge-intensive, low-work system implies empowerment, a redistribution of power away from corporate intellectual property, and liberation from the dominance of global value chains. If these conditions are absent, the switch to small farms, which should in principle be progressive, could actually be just another form of exploitation.” (p.86)

And again on p. 112: “…it is vital to establish a line of demarcation from co-optive strategies of neo-liberalism. Where the latter embraces themes of 'community', resilience, etc. in order to drag them away from radical class politics, we should assert that it is actually only through radical forces that we can arrive at a future where society and nature work on common principles.”

#to read #cartography #urban studies #urban agriculture #food studies

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biogenericpublishers · 4 years ago

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A Case-Study of the Physico-Chemical Parameters of the Public Water Supply in the University of Port Harcourt by Johnson Ajinwo OR in Open Access Journal of Biogeneric Science and Research

Abstract

Water –borne diseases is on the rise currently in the third world countries as a result of lack of routine water analysis checks to ensure that the desired quality of drinking water is upheld. In the light of the above, this research aimed at determining the physico-chemical properties and mineral content of seventeen water samples from the students’ residential areas and environs of the Main Campus of the University of Port Harcourt, Choba, Rivers State, Nigeria was carried out. The results showed that most of the physico-chemical quality indices of the water samples were within acceptable limits, except the nitrate levels of samples 13 and 14. The pH of all the samples were found to be acidic, with sample 12 having the lowest pH of 4.44. The hardness levels of the samples were determined to be very soft affirming the relationship between acidic pH and soft water. This increase in the corrosivity and plumbosolvency of the samples may result in long-term risk of metal poisoning from plumbing materials. However, the metal analysis showed only slight sodium and calcium contamination which may pose no health risk.

Introduction

About 829,000 people die annually from diarrhoea caused by poor sanitation, hand hygiene and drinking contaminated water. A number of diseases which include cholera, dysentery, diarrhoea, polio, typhoid and hepatitis A are transmitted through contaminated water and poor hygiene. Deaths from contaminated water are preventable and efforts aimed at tackling this ugly menace be put in place. The 2010 UN General Assembly emphasised that access to water and sanitation are basic human rights requirements. But water which is the number one liquid for life has come under intense pressure, owing to climate change, population explosion, urbanization and scarcity of water in many places. According to WHO, about 50% of the world’s population would be living in water-stressed areas in 2025 [1].

Water quality can be compromised by the presence of unwanted chemicals, micro-organisms and even radiological hazards. The problem of provision of good quality water for human consumption in Nigeria has been a major challenge that has received little or no attention. The National Agency for Food and Drug Administration and Control, (NAFDAC) is the body charged with the responsibility of ensuring the provision of good quality drinking water through the registration and quality assurance of commercially available drinking water [2]. However, majority of the Nigerian populace, in particular students shun commercially available water possibly due to the cost implication and still resort to water sources that lack quality assurance.

The vital role water plays include its ability to dissolve a wide range of substances, and has gained the status of being tagged the ‘universal solvent’. In the human body, two-thirds of the body is made up of water; which is the basic component of cells, tissues and the circulatory system. Due to the solvation character of water, cells are able to access nutrients in the body to produce energy, undergo metabolism and excrete waste in the body. Similarly, for drugs taken to elicit their desired activities, the drug substances must first be dissolved, prior to absorption into systemic circulation. It is well-known that acute dehydration may lead to death, which underscores the role of water as a life-sustaining fluid of great value and importance.

The University of Port Harcourt is sited in Choba community, Obio/Akpor Local Government Area of Rivers state, Nigeria. The state is one of the South-south states that constitute the oil-rich Niger-Delta Area, which has been the subject of oil exploration for more than 50 years. During this time, there have been oil spillages in the environment resulting in air, soil and water pollutions. This is evidenced in the recent United Nations Environment Programme (UNEP) report on the effects of oil spillages in Ogoniland in Rivers state. In this report water samples were obtained from boreholes drilled specifically for the research. The findings from the research revealed high levels of hydrocarbon, some organic and inorganic substances, some of which were carcinogenic [3]. The results further showed that in many locations, petroleum hydrocarbons had migrated to the groundwater. Furthermore, the host community of the University has also played host to an American oil exploration company for over two decades. To this end, it is expected that both soil and water in and around the community will be contaminated, especially with hydrocarbons and heavy metals.

This research aims to determine the physico-chemical parameters and the mineral content of the water sourced from deep water table within the students’ residential area and environs of the main campus of the University of Port Harcourt and to ascertain if the contamination is within safe limits. The standards by which this research would judge water quality is that prescribed by the World Health Organization (WHO), the United States Environmental Protection Agency (EPA) and the Nigerian Industrial Standard developed by the Standards Organization of Nigeria (SON).

Materials and Methods

1.1. Materials

1.1.1. Water Samples

Drinking water samples were collected from students’ residential areas and environs at the University of Port Harcourt Main Campus (Unipark, Abuja); the samples were collected from seventeen locations, which were described in (Table 1). The samples were collected using 2 L glass bottles fitted with an inner cork and an outer screw cap. The bottles were initially washed with detergent, rinsed thoroughly with tap water and then rinsed with distilled water. Prior to sample collection, the bottle was rinsed three times with the sample to be collected before collection. The samples were stored at room temperature. All titrations carried out in the physico-chemical analysis were done in triplicate for each sample and the average titre calculated.

1.2. Methods

1.2.1. pH Determination

Apparatus: pH Meter.

The pH meter was calibrated with standardized solutions of pH 4.0 and 9.1 respectively. The pH was read after inserting the electrode of the pH meter into the sample and allowing the reading to stabilize.

1.2.2. Total Alkalinity

1.2.3. Apparatus/Reagents: Burette, pipette, conical flasks, 0.001105 M HC1, phenolphthalein indicator, and methyl orange indicator.25 ml of the sample was pipetted into a conical flask and 2 drops of phenolphthalein indicator was added. There was no colour change (indicating the absence of carbonate and hydroxyl alkalinity). 2 drops of methyl orange indicator was added to the sample and titrated with the acid to a yellow endpoint.

1.2.4. Calculation:

Total Alkalinity (mg CaCO_3/L) =(M x V x 50000)/V_ (sample ) Bicarbonate Alkalinity (mg CaCO_3/L)=(M x V x 30500)/V_(sample )

Where M= molarity of HCI, V= titre value, and Vsample= Volume of Sample

1.2.5. Dissolved Co2 Content

Apparatus/Reagents: Burette, pipette, conical flasks, 0.01 M NaOH, phenolphthalein indicator.

25 ml of the sample was pipetted into a conical flask and 2 drops of phenolphthalein indicator was added. Titration was done against the base. Endpoint was determined by colour change from colourless to pink.

Calculation

Dissoved CO_2 (mg/L)=(V x N x E x 1000)/V_(sample )

Where V=titre value , N=normality of the base (0.0128), E=equivalent

Weight of co2(22),Vsample=Volume of Sample

1.2.6. Chloride Determination (Precipitation Titration)

Principle:

The principle behind this titration is the precipitation of C1 as AgCl by AgNO3 before AgCrO4 (red) is formed at the endpoint

Apparatus/Reagents: Burette, pipette, conical flasks, 0.014N AgNO3 and K2CrO4 indicator

25 ml of sample was pipetted into a conical flask, 2 drops of the indicator was added and this was titrated against AgNO3 solution until there was a colour change form yellow to brick red.

Calculation:

Chloride (mg/L) =(V x N x E x 1000)/V_(sample )

Where V= titre value, N= normality of AgNO3 (0.014), E= equivalent

Weight of chloride ion (35.5),Vsample=Volume of sample used

1.2.7. Silica Determination (Molybdosilicate Method)

Principle

The Molybdosilicate Method is based on the principle that at a pH of about 1.2, ammonium molybdate ((NH4)6M07024.4H20) reacts with any silica and phosphate present in a sample to form hetero-polyacids. Oxalic acid is then added no neutralize any molybdophosphoric acid present. This reaction produces a yellow colour whose intensity is proportional to the silica that reacted with the molybdate. Standard colour solutions of silica are also prepared and the colour intensity can be visually compared or its absorbance can be measured.

Apparatus: Conical flasks, beakers, pipettes, ammonium molybdate reagent: (NH4)6MO7O24.4H2O), 1:1 HCI, oxalic acid (H2C204.2H20)

Ammonium molybdate: prepared by dissolving 10g of (NH4)6M07024.4H20) in distilled water.

Oxalic acid: prepared by dissolving 7.5 g of H2C204.2H20 in 100 ml of distilled water.

Potassium Chromate (K2CrO4) Solution: prepared by dissolving 315 mg of K2CrO4 in distilled water and made up to 500 ml.

Borax Solution: prepared by dissolving 2.5 g of borate decahydrate Na2B407.10H20 in distilled water and made up to 250 ml.

The standard colour solution of concentrations 0.00 — 1.00 (mg Si/L) was prepared by mixing volumes of distilled water, potassium chromate and borax in the proportion given in (Table 2).

The absorbance of the standard was measured using a UV spectrophotometer at 390 nm. 50 ml of sample was pipetted into a beaker and 2 ml of ammonium molybdate and 1 ml of 1:1 HC1 were added to the beaker. The resulting solution was thoroughly mixed and allowed to stand for 7 minutes. 2 ml of oxalic acid was then added and after 2 minutes, the absorbance of the solution was measured at 390 nm.

Calculation:

The silica content of each sample was determined by means of simple proportion, using the formula:

(Absorbance of standard)/(concentration of silica in standard )=(Absorbance of sample)/(concentration of silica in sample )

1.2.8. Total Hardness Determination (Edta Titrimetric Method)

Principle

Ethylene Diaminetetraacetic Acid, (EDTA) and its sodium salt forms chelated soluble complex when added to a solution of certain metal cations. The addition of a small amount of a dye such as Eriochrome Black T to an aqueous solution containing calcium and magnesium ions at pH of about 10, results in a wine red coloured solution. If EDTA is added as a titrant, any magnesium or calcium will be complexed and the solution will turn from wine red to blue.

Apparatus/Reagents: Burette, pipette, conical flasks, 0.01 M EDTA, Ammonia buffer, Eriochrome Black T indicator. 50 ml of sample was pipetted into the conical flask and 5 drops of indicator was added. 20 ml of Ammonia buffer was added and the resulting mixture was titrated with 0.01 M EDTA solution. The endpoint was determined by a colour change from wine red to blue.

Calculation

Total Hardness (mgCaCO_3/L)=(V x M x E x 2.5 x 1000)/V_sample

Where V=titre value,M=concentration of EDTA,2.5= (molecular mass of Ca〖CO〗_3)/(atomic mass of Ca^(2+) )

E=equivalent weight of Ca^(2+) (40),and V_ sample=Volume of sample

1.2.9. Sulphate Determination (Turbidimetric Method)

Principle:

Sulphate ion is precipitated in a hydrochloric acid medium with barium chloride (BaCI2) to form barium sulphate (BaSO4) crystals of uniform size. The absorbance of the BaSO4 suspension is measured using a UV spectrophotometer and the sulphate ion concentration is determined from the calibration curved developed

Apparatus: UV spectrophotometer, conical flasks, pipettes, beakers, spatula, sulphate conditioning reagent, sulphate stock solution.

Preparation Of Conditioning Reagent: the conditioning reagent was prepared by mixing 45 g of NaCI, 18 ml of conc. HCI, 60 ml of 20 % isopropyl alcohol, 30 ml of glycerol and 180 ml of distilled water in a beaker and stirred thoroughly with a glass rod until the solution was clear. Preparation of Sulphate Stock Solution: this was prepared by dissolving 147.9 mg of anhydrous sodium sulphate (Na2SO4) in 1000 ml of distilled water. Preparation of Sulphate Standard Solution: 0.1, 0.2, 0.3, 0.4 and 0.5 ml respectively of the stock solution was pipetted into five 100 ml volumetric flasks and made up to the 100 ml mark with distilled water to produce 1, 2, 3, 4 and 5 ppm of the sulphate stock solution. These were then transferred into appropriately labelled stopper reagent bottles.

Formation Of Baso4 Turbidity: 5 ml of the conditioning reagent was added to the each of the 100 ml standard solution as well as to 100 ml of each sample. This was stirred for one minute. During stirring, a spatula full of BaCl2 crystals was added. The absorbance or each standard as well as each sample was measured using the UV spectrophotometer at 420 nm. The agitated samples were allowed to stand the in UV spectrophotometer for 4 minutes before recording the reading.

Calculation

The absorbance of the five standard solutions were plotted against their concentrations to obtain a calibration curve. The equation of the resulting curve (Equation 1) was used to calculate the sulphate ion content for each sample.

y = 0.0054x + 0 ----------(equation 1)

(R2 = 0.971)

Where y = sulphate ion content (mg/L), 0.0054 = slope, 0 = intercept, R2 = extent of linearity

1.2.10. Nitrate Determination (Brucine Colorimetric Method)

Apparatus/Reagents: UV Spectrophotometer, volumetric flasks, pipettes, beakers, brucine sulphanilic acid (brucine), conc. H2S04, 30 % NaC1, conc. HNO3, stock nitrate solution.

Preparation of Nitric Acid Stock Solution: 8.5 ml of conc. HNO3 was dissolved in distilled water and diluted to 500 ml in a 1000 ml measuring cylinder.

Preparation of Nitrate Standard Solution: 0.1, 0.2, 0.3, 0.4 and 0.5 ml respectively of the stock solution was pipetted into five 100 ml measuring cylinders and made up to the 100 ml mark with distilled water to produce 1, 2, 3, 4 and 5 ppm of the nitrate stock solution. These were then transferred into appropriately labelled conical flasks.

5 ml of the 1 ppm standard solution was pipetted into a volumetric flask. I ml of 30 % NaCI and 10 ml of conc. H2S04 was added gently to the 1 ppm solution, followed by the addition of 0.1 g of brucine. Upon mixing, a deep red colour which turned yellow was produced. The absorbance of the resulting solution was measured using a UV spectrophotometer at 410 nm. The above procedure was repeated using 5 ml each of the remaining as well as for each sample.

Calculation:

The absorbance of each of five standard solutions was plotted against their concentration to obtain a calibration curve. The equation of the resulting curve (Equation 2) was used to calculate the content for each sample.

y = 0.0038x + 0 ----------------- (Equation 2)

(R2=0.9747)

Where y = nitrate content (mg/L), 0.0038 = slope, 0 = intercept, R2 = extent of linearity

1.2.11. Determination of Calcium, Iron, Zinc, Lead,Chromium, Cadmium And Sodium Content by Atomic Adsorption Spectroscopy

The levels of the above mentioned heavy metals and non-heavy metals were determined using the atomic adsorption spectrometer of the following model: Bulk Scientific 205 AAA Model 210 VGP (with air-acetylene flame on absorbance mode and with injection volume of 7 ml/min). Calcium was determined at a wavelength of 423 nm, sodium at 589 nm, iron at 248, zinc at 214 nm, chromium 357nm, cadmium at 228 nm and lead at 283 nm.

Standard metal solutions for each metal were prepared and calibration curves for each metal were obtained from a linear plot of the absorbance of the standard against their concentrations in mg/L. This was used to determine the concentration of each metal in each sample by extrapolation from the calibration curves. The instrument was first calibrated to zero by aspirating a blank solution in the nebulizer. The samples were then aspirated in the nebulizer at 7 ml/min and the absorbance of each sample recorded.

Where M= molarity of HCI, V= titre value, and Vsample= Volume of Sample

1.2.5. Dissolved Co2 Content

Apparatus/Reagents: Burette, pipette, conical flasks, 0.01 M NaOH, phenolphthalein indicator.

Calculation

Where V=titre value , N=normality of the base (0.0128), E=equivalent

Weight of co2(22),Vsample=Volume of Sample

1.2.6. Chloride Determination (Precipitation Titration)

Principle:

The principle behind this titration is the precipitation of C1 as AgCl by AgNO3 before AgCrO4 (red) is formed at the endpoint

Apparatus/Reagents: Burette, pipette, conical flasks, 0.014N AgNO3 and K2CrO4 indicator

25 ml of sample was pipetted into a conical flask, 2 drops of the indicator was added and this was titrated against AgNO3 solution until there was a colour change form yellow to brick red.

Calculation:

Where V= titre value, N= normality of AgNO3 (0.014), E= equivalent

Weight of chloride ion (35.5),Vsample=Volume of sample used

1.2.7. Silica Determination (Molybdosilicate Method)

Principle

Apparatus: Conical flasks, beakers, pipettes, ammonium molybdate reagent: (NH4)6MO7O24.4H2O), 1:1 HCI, oxalic acid (H2C204.2H20)

Ammonium molybdate: prepared by dissolving 10g of (NH4)6M07024.4H20) in distilled water.

Oxalic acid: prepared by dissolving 7.5 g of H2C204.2H20 in 100 ml of distilled water.

Potassium Chromate (K2CrO4) Solution: prepared by dissolving 315 mg of K2CrO4 in distilled water and made up to 500 ml.

Borax Solution: prepared by dissolving 2.5 g of borate decahydrate Na2B407.10H20 in distilled water and made up to 250 ml.

The standard colour solution of concentrations 0.00 — 1.00 (mg Si/L) was prepared by mixing volumes of distilled water, potassium chromate and borax in the proportion given in (Table 2).

1.2.8. Total Hardness Determination (Edta Titrimetric Method)

Principle

1.2.9. Sulphate Determination (Turbidimetric Method)

Principle:

Apparatus: UV spectrophotometer, conical flasks, pipettes, beakers, spatula, sulphate conditioning reagent, sulphate stock solution.

Calculation

y = 0.0054x + 0 ----------(equation 1)

(R2 = 0.971)

Where y = sulphate ion content (mg/L), 0.0054 = slope, 0 = intercept, R2 = extent of linearity

1.2.10. Nitrate Determination (Brucine Colorimetric Method)

Apparatus/Reagents: UV Spectrophotometer, volumetric flasks, pipettes, beakers, brucine sulphanilic acid (brucine), conc. H2S04, 30 % NaC1, conc. HNO3, stock nitrate solution.

Preparation of Nitric Acid Stock Solution: 8.5 ml of conc. HNO3 was dissolved in distilled water and diluted to 500 ml in a 1000 ml measuring cylinder.

Calculation:

y = 0.0038x + 0 ----------------- (Equation 2)

(R2=0.9747)

Where y = nitrate content (mg/L), 0.0038 = slope, 0 = intercept, R2 = extent of linearity

1.2.11. Determination of Calcium, Iron, Zinc, Lead,Chromium, Cadmium And Sodium Content by Atomic Adsorption Spectroscopy

Results and Discussions

The results of the Physico-chemical characteristics of the sampled water sources are presented in (Table 3) below. From the results, the samples can be classified as generally soft. The highest hardness value from the result was 14.67 ± 0.00. According to the Twort Hardness classification, this falls in the soft water category [4]. This is directly related to the calcium levels of the samples. Calcium accounts for about two-thirds of water hardness. The recommended upper limit of calcium in drinking water is 50 mg/L. The calcium values were all less than 6.0 mg/L and this reflected in the low hardness values obtained.

The pH values of all samples were not within the acceptable limit of pH for safe drinking-water. The pH values of all the samples were generally acidic with a range of 4.44 to 6.06. Samples 3, 4, 5, 7, 8, 10, 12 and 17 all had values below 5.0, with sample 12 having the lowest value of 4.44. The acidic nature of most samples can be attributed to the low hardness (soft water) of the samples. Soft water is known to be acidic and this increases the ‘plumbosolvency’ of such water.

Dissolved CO2 is one of the components of carbonate equilibrium in water. The highest value of CO2 was 12.02 ± 1.50 mg/L. Dissolved CO2 is significant in that high values of it (usually above 10 mg/L for surface waters) indicates a significant biological oxidation of the organic matter in water. Dissolved CO2 also has a direct relationship with pH and alkalinity. From the results, the dissolved CO2 level is low for all samples, indicating little biological oxidation of organic matter. At pH values between 4.6 and 8.3, bicarbonate alkalinity is in equilibrium with dissolved CO2. The generally low values of dissolved CO2 corresponds therefore to the generally low (bicarbonate) alkalinity.

Chloride in water does not have a negative health impact. Its impact is aesthetic in nature, with high concentrations exceeding 250 mg/L producing a salty taste (when the associated cation is sodium). The chloride levels of all samples were quite low, the highest value being 66.28 ± 1.33 mg/L.

The silica and sulphate concentrations were very low. The limits are 1-30 mg/L and 250 mg/L, respectively [5]. The silica content was almost insignificant (all less than 0.1 mg/L). The sulphate content was also very low; the highest being 2.96 mg/L for sample 14, and in some cases not determinable (samples. 11 and 15). Nitrate is naturally present in soil, water and food due to the nitrogen cycle. The activities of man also add to increase the nitrate levels in the environment. To this end, WHO and NIS set a limit of 50 mg/L, while EPA stipulates a stricter standard of not more than 10 mg/L (nitrate as nitrogen). The range of nitrate concentration for the samples was 11.32 — 58.68 mg/L by WHO and NIS [6].

Standard samples 13 and 14 have excess of nitrate (58.68 and 52.11 mg/L respectively). The nitrate concentration of sample 12 is just at the threshold (50 mg/L). Nitrate levels can become dangerously increased with the increased use of nitrogen based fertilizers and manure, coupled with the fact that nitrate is extremely soluble. The environment around the boreholes are such that support thriving of bacteria which play a significant role in the nitrogen cycle. Nitrogen easily leaches into groundwater from runoff [7]. Since the sample area is inhabited by mainly adults, the most lethal health effect of nitrate poisoning is not expected to be seen (infants are much more sensitive than adults to methaemoglobinaemia caused by nitrate, and essentially most deaths due to nitrate poisoning have been in infants). However, long term exposure to nitrates can, apart from causing methaemoglobinaemia and anaemia, cause diuresis, starchy deposits and haemorrhaging of the spleen. Nitrites in the stomach can react with food proteins to form nitrosoamines; these compounds can also be produced when meat containing nitrites or nitrates is cooked, particularly using high heat. While these compounds are carcinogenic in test animals, evidence is inconclusive regarding their potential to cause cancer (such as stomach cancer) in humans. The Levels of some selected heavy and non-heavy metals in the water samples were determined and the results shown in (Table 4).

The AAS determination of heavy and non-heavy metals showed that the samples were free from these metals except for sodium and calcium. The range of values for sodium was 0.40 — 16.30 mg/L, well below the guideline value set at 50 mg/L for sodium [8]. Sample 17 was the only sample with a trace of zinc (0.13 mg/L) and this was well below the limit of 3 mg/L set by NIS [9] and 5 mg/L set by EPA [10] The increased corrosivity of these samples therefore has an increased associated risk of dissolving metals and non metals including lead, iron, zinc, nickel, brass, copper and cement/concrete [8]. If the water distribution system was laid with pipes containing any of these metals, then the risk of increased levels of these, especially lead would be high. However, this seems not to be the case because the lead levels obtained from AAS analysis of all the samples were all either zero or very low.

Conclusion And Recommendation

The physico-chemical analyses performed on the samples, demonstrated that the physico-chemical quality of the water samples were mostly within the specified limits as stated by WHO and EPA. The health implications of the physico-chemical quality were considered to be of importance on the longterm basis, since these contaminants at the levels at which they occurred in the water samples can accumulate over time. The pH of the samples was found to be acidic. It can be concluded that the same acidic aquifer serves the entire sample area. The pH of water must be controlled through increasing alkalinity and calcium levels since acidic water tends to be corrosive and can dissolve metal fittings and cement into water, leading to contamination. Also, the nature of construction materials that have been used and that will be used in the future should be reviewed to ensure that it can withstand the acidity of the water. It was not in the scope of this research to determine the size of the underground water aquifer, but it is recommended therefore that the size of the underground aquifer be determined in other to ascertain the extent to which the recommendations for remediation proposed herein would be implemented. The nitrate levels of 2 samples were also found to exceed the acceptable limit (50 mg/L as nitrate ion), while one sample had 50 mg/L as its value. It is recommended that biological denitrification for surface water and ion exchange for ground water is employed in order to reduce the nitrate levels.

Conflict of Interest

The authors have no conflict of interest to declare.

More information regarding this Article visit: OAJBGSR

https://biogenericpublishers.com/pdf/JBGSR.MS.ID.00151.pdf

https://biogenericpublishers.com/jbgsr.ms.id.00151.text/ For more open access journals click on https://biogenericpublishers.com/

#ACase-Study Physico-ChemicalParameters #Johnson Ajinwo OR #OAJBGSR #JBGSR #Public Water Supply

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sciencespies · 5 years ago

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Here's Why This Smithsonian Scientist Studies Ancient Pathogens

https://sciencespies.com/nature/heres-why-this-smithsonian-scientist-studies-ancient-pathogens/

Here's Why This Smithsonian Scientist Studies Ancient Pathogens

Smithsonian Voices National Museum of Natural History

Get to Know the Scientist Studying Ancient Pathogens at the Smithsonian

April 14th, 2020, 6:00AM / BY

Margaret Osborne

Sabrina Sholts is the curator of biological anthropology at the Smithsonian’s National Museum of Natural History. (Paul Fetters, Smithsonian)

Meet a SI-entist: The Smithsonian is so much more than its world-renowned exhibits and artifacts. It is a hub of scientific exploration for hundreds of researchers from around the world. Once a month, we’ll introduce you to a Smithsonian Institution scientist (or SI-entist) and the fascinating work they do behind the scenes at the National Museum of Natural History.

When Dr. Sabrina Sholts curated the exhibition “Outbreak: Epidemics in a Connected World” in 2018,” she never imagined that two years later, the museum would close because of a coronavirus pandemic.

As a biological anthropologist focused on health, diseases are part of Sholts’ specialty. Sholts studies how human, animal and environmental health are connected, lately focusing on our microbiome—the communities of microorganisms that thrive on and inside our bodies – along with the pathogens that can cause illness.

Sholts tells us more about her work at the National Museum of Natural History and the “Outbreak” exhibition and gives advice to the next generation of scientists in the following interview.

Can you describe what you do as curator of biological anthropology at the museum?

I study the biological aspects of humanity – the biological molecules, structures, and interactions that are involved in being human. I’m particularly interested in health. It’s fascinating how we can understand disease as an expression of how we interact with our environment — the environment being pretty much everything that’s not our bodies. So from metals in our water, soil and food to microbes that are not only part of us and good for us, but also those that can be harmful.

My research can be a bit diverse, but for me, it’s easy to see the themes — I’m looking at connections between human, animal and environmental health to understand how human impact on ecosystems can affect us.

What are you working on right now?

I’ve got a great group of students in my lab right now, Rita Austin, Andrea Eller, Audrey Lin and Anna Ragni – as well as wonderful colleagues across the museum. We’re doing a few different things.

One large project that’s been going on for several years is looking at indicators of health and disease in our primate collections from different human-modified environments. Andrea conceived the project, and we’re looking at how we might relate some of those conditions to changes in the microbiome.

I’m also working with Audrey and fellow curator Logan Kistler on ancient pathogen research using the museum’s vertebrate zoology collections. We’re interested in the evolutionary history of some human viruses that originate in wildlife, like the one that caused the 1918 influenza pandemic.

Some of my work is what we call bioarcheology. It’s the study of human remains in archeological contexts. I was recently in Amman with my colleagues Wael Abu Azizeh and Rémy Crassard, where I was looking at an ancient skeleton that they excavated as part of their ongoing expedition in southern Jordan. Bones and teeth can provide more information about the diet, health, and movement of people in the past.

Sholts works on an archaeological skeleton in Jordan. (Rémy Crassard)

How has your research changed since the COVID-19 pandemic?

We can’t go into the museum, we can’t access specimens, we can’t use our labs and we can’t go into the field. We can’t do a lot of the things we’ve come to rely on for the research that we’ve been trained to do.

But already you see people adapting, brainstorming and really trying to work around these challenges in new ways. So we’re having these virtual conversations, and thinking about how we can continue with our research in creative ways. Because of the COVID-19 pandemic, I’m forming new, virtual collaborations – not just for doing science but also in communicating its role in all of this.

What excites you about working at the Smithsonian?

I’ve got the perfect combination of doing really exciting research, and also being able to see and experience how it can be shared. I didn’t imagine when I got the job that I would become so passionate about outreach and connecting to the public through our programs and our exhibits — we can impact people in so many ways.

Do you have a favorite item in the collection or one that sticks out to you at the moment?

That’s a really hard thing to ask a curator. We spend so much time researching collection items and writing papers based on our findings. Some scientists compare publishing a paper to giving birth. You can get very attached to every single one of these publications and whatever they’re about.

So we’ve just “birthed” another one. It’s about the cranium of a chimpanzee, which we came across in our survey of the primate collections. It’s notable because there are tooth marks on it that suggest that it was chewed on by a somewhat large mammalian carnivore, maybe a leopard. Along the way, we gave it a cute name — we call it “Chimp Chomp.” The paper, literally called “A Chomped Chimp,” just came out. I have to say, seeing all the lovely photos, right now, that’s probably my favorite.

What are you most proud of accomplishing so far in your career?

I’m very proud of what we’ve done with the “Outbreak” exhibit. Particularly because of its “One Health” message and huge network of supporters and partners that we convened. The exhibit shows people how and why new diseases emerge and spread, and how experts work together across disciplines and countries to lower pandemic risks.

A pandemic is certainly not something that we knew would happen during the exhibit’s run. You hope an exhibit like that won’t become so relevant as it has with the COVID-19 outbreak. But I’m grateful that it’s prepared me to help the public understand what’s going on right now and communicate the science of it.

Sholts works with her team to develop content for the “Outbreak” exhibition. (Sally Love, Smithsonian)

What advice would you give to your younger self or to the next generation of biological anthropologists?

Appreciate the value of having someone to guide you and mentor you — someone who really cares about you. Understand its significance and carry that relationship throughout your career, if you can.

And be open-minded. Don’t be afraid to work at the intersections of where disciplines and fields traditionally divide us. Have conversations that may put you at a disadvantage in terms of what you know, or what’s familiar, but from which you can learn a lot and hear different perspectives. Embrace a broad skill set and a really diverse community of peers and partners.

Why is having a diverse community of peers important?

We need different ideas. We need to see things from every possible angle to get the most out of anything we study, learn and understand. I think that if you only interact with and listen to people who are like you, you limit the kinds of conversations you have. You’re going to miss some other valuable ways of looking at things.

Sholts looks at data from a CT scan with colleagues at the National Museum of Natural History. (Smithsonian)

Have you had any mentors or role models that helped get you where you are today? Is that something that you think about now that you’re at the top of your field?

I’ve had a number of really significant mentors and guides on this journey, going all the way back to even before high school. I credit them all.

When I was a student, I was operating with so much support. I had the independence to pursue something that I was interested in. That’s something I try to do with my students: give them the freedom, flexibility and encouragement to really pursue their interests as they grow.

I take very seriously the privilege to be able to support such amazing young scientists and to facilitate the incredible work that they’re doing and that we can do together.

Related stories: ‘One Health’ Could Prevent the Next Coronavirus Outbreak Meet the Smithsonian’s Newest Chief Scientist New Smithsonian Exhibit Spotlights ‘One Health’ to Reduce Pandemic Risks

Margaret Osborne is an intern in the Smithsonian National Museum of Natural History’s Office of Communications and Public Affairs. Her journalism has appeared in the Sag Harbor Express and aired on WSHU public radio. Margaret is an undergraduate at Stony Brook University, where she majors in journalism and German language and literature and minors in environmental studies. She’s spending her last semester in Washington, D.C. and will graduate in May.