Animals and soil sustainability

Domestic livestock animals and soils must be considered together as part of an agroecosystem which includes plants. Soil sustainability may be simply defined as the maintenance of soil productivity for future generations. There are both positive and negative aspects concerning the role of animals in soil sustainability. In a positive sense, agroecosystems which include ruminant animals often also include hay forage-or pasture-based crops in the humid regions. Such crops stabilize the soil by decreasing erosion, improving soil structure and usually require fewer chemical inputs. Monogastric animal culture is based on an agroecosystem consisting of mainly grain crops. These crops can result in the soil being exposed to water and wind erosion although soil conservation practices that significantly reduce soil losses may be followed. The management of animal manures is not always compatible with soil conservation practices. Careful management of the nutrients in manure is absolutely necessary to avoid nitrate contamination of ground water or phosphorus loading of streams and lakes. In a negative sense, increases in animal livestock populations in association with human population growth are promoting desertification in the arid and semi-arid regions of the world. The key component for a fully compatible and acceptable association between domestic animals and soil productivity is proper management. Careful management of the components of an animal-based agroecosystem is required if soil productivity and environmental quality are to be maintained. Although we have much to learn, technologies are available to move a considerable way towards this ideal state.     

Hazard and Effects of Pollution by Lead on Vegetable Crops

Lead (Pb) contamination of the environment is an important human health problem. Children are vulnerable to Pb toxicity; it causes damage to the central nervous system and, in some extreme cases, can cause death. Lead is widespread, especially in the urban environment, and is present in the atmosphere, soil, water and food. Pb tends to accumulate in surface soil because of its low solubility, mobility, and relative freedom from microbial degradation of this element in the soil. Lead is present in soil as a result to weathering and other pedogenic processes acting on the soil parent material; or from pollution arising caused by the anthropogenic activities; such as mining, smelting and waste disposal; or through the adoption of the unsafe and unethical agricultural practices such as using of sewage sludge, and waste water in production of vegetable crops or cultivation of vegetables near highways and industry regions. Lead concentrations are generally higher in the leafy vegetables than the other vegetables. Factors affecting lead uptake included its concentration in the soil, soil pH, soil type, organic matter content, plant species, and unsafe agriculture practices. Generally, as Pb concentration increased; dry matter yields of roots, stems and leaves as well as total yield decreased. The mechanism of growth inhibition by lead involve: a decrease in number of dividing cells, a reduction on chlorophyll synthesis, induced water stress to plants, and decreased NO ₃ ^- uptake, reduced nitrate and nitrite reductase activity, a direct effect of lead on protein synthesis, a decrease on the uptake and concentration of nutrients in plants. The strategies to minimize Pb hazard can be represented in: (a) Phytoremediation, through natural plants are able to bio-accumulate Pb in their above–ground parts, which are then harvested for removal such as, using Indian Mustard (Brassica juncea), Ragweed (Ambrosia artemisiifolia), Hemp Dogbane (Apocynum cannabium), or Poplar trees, which sequester lead in its biomass. (b) Good and ethical agricultural practices such as cultivation of vegetables crops as far from busy streets or highways and industry regions as well as nonuse of sewage sludge and waste water in cultivated soils. (c) Increasing the absorptive capacity of the soil by adding organic matter and humic acid. (d) Growing vegetable crops and cultivars with a low potential to accumulate lead, especially in soils exposed to atmospheric pollution. (e) Washing of leafy vegetables by water containing 1 % vinegar or peeling roots, tubers, and some fruits of vegetables before consumption may be an important factor in reducing the lead concentration.     

Soil organic carbon sequestration in cotton production systems of the southeastern United States: a review

Past agricultural management practices have contributed to the loss of soil organic carbon (SOC) and emission of greenhouse gases (e.g., carbon dioxide and nitrous oxide). Fortunately, however, conservation-oriented agricultural management systems can be, and have been, developed to sequester SOC, improve soil quality, and increase crop productivity. Our objectives were to (i) review literature related to SOC sequestration in cotton (Gossypium hirsutum L.) production systems, (ii) recommend best management practices to sequester SOC, and (iii) outline the current political scenario and future probabilities for cotton producers to benefit from SOC sequestration. From a review of 20 studies in the region, SOC increased with no tillage compared with conventional tillage by 0.48 +/- 0.56 Mg C ha(-1) yr(-1) (H(0): no change, p < 0.001). More diverse rotations of cotton with high-residue-producing crops such as corn (Zea mays L.) and small grains would sequester greater quantities of SOC than continuous cotton. No-tillage cropping with a cover crop sequestered 0.67 +/- 0.63 Mg C ha(-1) yr(-1), while that of no-tillage cropping without a cover crop sequestered 0.34 +/- 47 Mg C ha(-1) yr(-1) (mean comparison, p = 0.04). Current government incentive programs recommend agricultural practices that would contribute to SOC sequestration. Participation in the Conservation Security Program could lead to government payments of up to Dollars 20 ha(-1). Current open-market trading of C credits would appear to yield less than Dollars 3 ha(-1), although prices would greatly increase should a government policy to limit greenhouse gas emissions be mandated.     

云南大理洱海流域农业面源污染防治和生态补偿实践

洱海是大理人民赖以生存和发展的＂母亲湖＂,保护洱海是全州实现可持续发展的前提和基础,保护洱海就是保护大理发展的根基。＂治湖先治污,治污先治源＂。近年来大理州委、州政府及流域各级农业部门高度重视洱海农业面源污染防治及生态补偿工作,总结、提炼了一些成功的生态补偿经验和做法,特别是在种养结构调整、测土配方施肥、畜禽粪便资源化利用、农产品质量安全、稻田养殖生态鱼等方面实施了大量的以项目形式的生态补偿实践,同时在生态补偿的理论、政策、措施,补偿对象、补偿方式、补偿资金等方面作了初步探索,取得了明显成效,洱海流域农业面源污染控制初步实现了＂控源、减排、循环、利用＂的目标。本文通过总结大理州近年来以项目形式实施的农业生态补偿机制体制的经验,旨在为保护高原湖泊实施农业生态补偿提供科技支撑。     

Effect of agricultural extension on cotton farmer's efficiency in arid and semi-arid areas of Burkina Faso

This study shows that farmers in arid and semi-arid land can improve their efficiency if they have access to agricultural extension services. An exhaustive survey was used to obtain data from 423 cotton producers in the arid zones and 144 of wetlands in Burkina Faso. The method of the directional distance function modeling a multi-output technology was used. The results show that cotton farmers in the arid zones are not technically more inefficient than those in wetlands. On average, arid zone producers have a technical inefficiency of 0.056 while that of wetland producers is around 0.052. The agricultural extension, defined as receiving visits and advice from technical agents, is important for producers because it helps farmers choose soil and water conservation techniques and fertilizers adapted to the Agro-climatic conditions of their respective zones. Agriculture extension also helps farmers of the arid zones to reduce their technical inefficiency by advising them to cultivate small agricultural plots. On average, in these zones, the size of an agricultural plot is around 1.03 ha compared to those of wetlands which is about 1.6 ha.     

Application of Sample Selection Model in Estimating Response Functions for Nitrate Percolation

The Seymour aquifer region of Texas has been identified as containing elevated levels of nitrate in ground water. Various state and federal agencies are currently studying policy options for the region by gathering more site-specific information. However, because of lack of sufficient information, cause and effect relationships between water quality and agricultural practices have not been well established for the region. Some recently available biophysical simulation models have impressive capabilities in generating large amounts of data on environmental pollution resulting from agricultural production practices. In this study, the data generated by a biophysical simulation model were used to estimate the nitrate percolation response functions for the Seymour aquifer region. Interestingly, nitrate percolation values obtained from simulation models often comprise acensoredsample because the non-zero percolation values are only observed under certain climatic events and input levels. It has been shown in the econometric literature that the use of Ordinary Least Squares (OLS) on censored sample data produces biased and inconsistent parameter estimates. Thus, a sample selection model was used in this study to estimate the response functions for nitrate percolation. The study provides some insight into the relationship between nitrate percolation and agricultural production practices. In particular, the study demonstrates the potential of selected design standards in minimizing agricultural nonpoint-source (NPS) pollution for the study area.     

秋作的资源利用及效益分析

本文针对四川攀西地区冬干春旱的气候特点,分析了9种晚秋作物的产量、经济效益、生长发育动态及资源利用状况。结果表明,在8月底播种或移栽条件下,秋大麦、秋洋芋、秋豌豆、秋荞麦及秋菜的产量或效益较高。不同秋作可供不同地点或不同种植制度下选择。文章还对主要秋作的关键栽培技术进行了讨论。     

Local Perception of Environmental Change in a Semi-Arid Area of Northeast Brazil: A New Approach for the Use of Participatory Methods at the Level of Family Units

The diversity of plant resources in the Brazilian semi-arid region is being compromised by practices related to agriculture, pastures, and forest harvesting, especially in areas containing Caatinga vegetation (xeric shrublands and thorn forests). The impact of these practices constitutes a series of complex factors involving local issues, creating a need for further scientific studies on the social-environmental dynamics of natural resource use. Through participatory methods, the present study analyzed people’s representations about local environmental change processes in the Brazilian semi-arid region, taking into consideration local production systems, natural resources, and their importance. Environmental historical graphs were developed with nine local families to analyze landscape changes with regard to cultivated areas and pastures, and their relationship with the availability of native vegetation. Punctuation exercises were performed to observe the importance of each unit that supplied native and cultivated resources. The availability of native resources in the environment is subject to stability, as observed by a majority of the local families. The role of the production units (crops and pastures) was emphasized by most families in the study, especially because of the need for products for subsistence needs and income generation. The current decline of such practices is a consequence of an exodus of field workers and also relates to the conservation of native species that otherwise would have been deforested in favor of agricultural practices.     

Socio-economic Comparison Between Traditional and Improved Cultivation Methods in Agroforestry Systems, East Usambara Mountains, Tanzania

The East Usambara Mountains, recognized as one of the 25 most important biodiversity hot spots in the world, have a high degree of species diversity and endemism that is threatened by increasing human pressure on resources. Traditional slash and burn cultivation in the area is no longer sustainable. However, it is possible to maintain land productivity, decrease land degradation, and improve rural people’s livelihood by ameliorating cultivation methods. Improved agroforestry seems to be a very convincing and suitable method for buffer zones of conservation areas. Farmers could receive a reasonable net income from their farm with little investment in terms of time, capital, and labor. By increasing the diversity and production of already existing cultivations, the pressure on natural forests can be diminished. The present study shows a significant gap between traditional cultivation methods and improved agroforestry systems in socio-economic terms. Improved agroforestry systems provide approximately double income per capita in comparison to traditional methods. More intensified cash crop cultivation in the highlands of the East Usambara also results in double income compared to that in the lowlands. However, people are sensitive to risks of changing farming practices. Encouraging farmers to apply better land management and practice sustainable cultivation of cash crops in combination with multipurpose trees would be relevant in improving their economic situation in the relatively short term. The markets of most cash crops are already available. Improved agroforestry methods could ameliorate the living conditions of the local population and protect the natural reserves from human disturbance.     

PREDICTIVE ASSESSMENT OF SEVERITY OF AGRICULTURAL DROUGHTS BASED ON AGRO-CLIMATIC FACTORS1

ABSTRACT: Past historical evidence indicates that droughts have had great impacts on human life. Drought (or scarcity of water) is assessed based on two key factors, namely, the estimated water demand, and the expected water supply. The formulation of these key factors for a region largely depends on the agro-climatic and economic conditions. Consideration of one such key factor is the relationship between the crop yield and water deficit in the assessment and prediction of agricultural droughts. The varying nature of this relationship from crop to crop adds to the complexity of agricultural drought analysis. To overcome this difficulty in analyzing agricultural droughts of a region, it is adequate to consider and place emphasis on a single crop (i.e., an index crop) grown homogeneously over the major area of the region. From one year to another year, the pattern of water requirement during the growing season of an index crop is rather stationary, and the water supply in arid and semi-arid area is mainly from seasonal random precipitation. In a region, grain yield of the index crop and, in turn, assessment of the severity of drought can reasonably be predicted as a function of the time of crop sowing and the distribution of rainfall, provided that temporal and spatial effects of other contributing factors (crop variety, soil fertility status, crop disease, pest control, cultivation practices etc.) on grain yield are considered to be uniformly distributed (i.e., stable). A predictive method of assessing agricultural droughts in an arid area of western India is presented. The major crop (Pearl Millet) of this region is grown from. July through September. The formulation of the proposed predictive method inherently implies that the grain yield of the main crop is a reliable indicator of agricultural drought. In the development of this predictive relationship (i.e., a regression type model) a number of potential yet simple variables affecting the grain yield in the region were investigated. The soil moisture index, although generally considered significant compared to the simple variables, has been found to account for insignificant variation in the grain yield. Results of our investigations suggest that it would be advisable to exclude the soil moisture index variable from the model. The proposed regression model can be used in the prediction of grain yield of the main crop several months ahead of crop harvesting operations and, in turn, the assessment of agricultural drought severity as mild, moderate, or severe. Such an assessment is expected to be helpful to planners for arranging appropriate measures to effectively combat agricultural drought situations.     

Investments in agricultural water management for poverty reduction in Africa: Case studies of Limpopo,Nile, and Volta river basins

Much of Sub‐Saharan Africa is burdened with water scarcity and poverty. Continentally, less than four percent of Africa's renewable water resources are withdrawn for agriculture and other uses. Investments in agricultural water management can contribute in several ways to achieving the Millennium Development Goals of eradicating extreme poverty and hunger and ensuring environmental sustainability. Increased yield and cropping area and shifts to higher valued crops could help boost the income of rural households, generate more employment, and lower consumer food prices. These investments can also stabilize output, income and employment, and have favourable impacts on education, nutrition and health, and social equity. Investments in agricultural water management can cut poverty by uplifting the entitlements and transforming the opportunity structure for the poor. The overall role of investments in agricultural water management in eradicating hunger and poverty is analyzed. This paper contributes to the present debate and efforts to identify strategies and interventions that can effectively contribute to poverty reduction in Africa. It provides an overview of population growth, malnutrition, income distribution and poverty for countries in three case study river basins — Limpopo, Nile, and Volta. With discussions on the contribution of agriculture to national income and employment generation, the paper explores the linkages among water resources investments, agricultural growth, employment, and poverty alleviation. It examines the potential for expansion in irrigation for vertical and horizontal growth in agricultural productivity, via gains in yield and cropping area to boost the agricultural output. Factors constraining such potential, in terms of scarcity and degradation of land and water resources, and poor governance and weak institutions, are also outlined. The paper argues that increased investments in land and water resources and related rural infrastructure are a key pathway to enhance agricultural productivity and to catalyze agricultural and economic growth for effective poverty alleviation.     

Harvesting of rainwater and brooklets water to increase mountain agricultural productivity: A case study from a dry valley of southwestern China

In semi-arid valleys of southwestern China, seasonal shortage of water is the major contributing factor to low and unstable crop yield. Harvesting of both rainwater and brooklets water in the semi-arid valleys of Ningnan county of Sichuan Province has brought about considerable economic and environmental change. Brooklet water is collected throughout the year but mainly during the rainy season in a series of ponds while rainwater is harvested in underground tanks constructed on road side or land boundaries with only a small opening above ground to save limited cropland. Increased water availability has promoted cultivation of sugarcane, tobacco, and mulberry, and increased per unit area yield of food crops. Sericulture, sugarcane and tobacco have become three important sources of farmers' income. The water harvesting has contributed considerably to increased rural income, poverty reduction, reduced soil erosion and improvement in overall environment. Government has played a key role in planning and implementation of water harvesting programmes. Financial support of government and clear ownership of water harvesting facilities are critical for the success of the programme. Application of similar water harvesting techniques in other areas with similar biophysical conditions would contribute to enhancing the rural economy and alleviating poverty.     

Soil, water and nutrient conservation in mountain farming systems: case-study from the Sikkim Himalaya

The Khanikhola watershed in Sikkim is agrarian with about 50% area under rain-fed agriculture representing the conditions of the middle mountains all over the Himalaya. The study was conducted to assess overland flow, soil loss and subsequent nutrient losses from different land uses in the watershed, and identify biotechnological inputs for management of mountain farming systems. Overland flow, soil and nutrient losses were very high from open agricultural (cropped) fields compared to other land uses, and more than 72% of nutrient losses were attributable to agriculture land use. Forests and large cardamom agroforestry conserved more soil compared to other land uses. Interventions, like cultivation of broom grass upon terrace risers, N2-fixing Albizia trees for maintenance of soil fertility and plantation of horticulture trees, have reduced the soil loss (by 22%). Soil and water conservation values (> 80%) of both large cardamom and broom grass were higher compared to other crops. Use of N2-fixing Albizia tree in large cardamom agroforestry and croplands contributed to soil fertility, and increased productivity and yield. Bio-composting of farm resources ensured increase in nutrient availability specially phosphorus in cropped areas. Agricultural practices in mountain areas should be strengthened with more agroforestry components, and cash crops like large cardamom and broom grass in agroforestry provide high economic return and are hydroecologically sustainable.     

Adoption of sustainable agriculture practices: Evidence from a semi-arid region of Ethiopia

In the wake of the resource constraints for external farm inputs faced by farmers in developing countries, sustainable agriculture practices that rely on renewable local or farm resources present desirable options for enhancing agriculture productivity. In this study, plot-level data from the semi-arid region of Ethiopia, Tigray are used to investigate the factors influencing farmers' decisions to adopt agriculture practices, with a particular focus on conservation tillage, compost and chemical fertilizer. A trivariate probit model is used to analyze the determinants of adoption of these practices. In addition, stochastic dominance analysis is used to compare the productivity impacts of compost with that of chemical fertilizer based on a six-year cross-sectional farm-level dataset. Our results indicate heterogeneity with regard to the factors that influence adoption decisions of the three practices and the importance of both plot and household characteristics on influencing adoption decisions. In particular, we found that household endowments and access to information, among other factors, impact the choice of sustainable farming practices significantly. Furthermore, the use of stochastic dominance analysis supported the contention that sustainable farming practices enhance productivity. They even proved to be superior to the use of chemical fertilizers — justifying the need to investigate factors that influence adoption of these practices and to use this knowledge to formulate policies that encourage adoption.     

AGRICULTURAL POLLUTION CONTROL: IMPLICATIONS FROM THE RURAL CLEAN WATER PROGRAM1

ABSTRACT: The Rural Clean Water Program has provided a unique opportunity to study the economics of agricultural nonpoint source pollution control. Several implications for improving the economic efficiency of future agricultural nonpoint source pollution control programs can be drawn from the results. First, individual projects should be targeted towards water bodies that have water quality problems causing economic damages. Considerable variation can exist among areas in the magnitude of economic damages, which may not be proportional to physical impacts. Second, the relative costs and effectiveness of the practices selected to reduce the delivery of pollutants can vary dramatically from one location to another. Early identification and emphasis on cost-effective BMPs can substantially reduce project costs and may make a project economically justifiable that would not otherwise be so. Finally, some projects that do not hive potential economic benefits from water quality improvements exceeding government cost may have on-farm benefits from reduced costs and increased long-term yields that are sufficient to make total benefits (water quality and on-farm) exceed costs.     

FLOODPLAIN MANAGEMENT NEEDS PECULIAR TO ARID CLIMATES1

ABSTRACT: Many practices followed uniformly nationwide in the federal flood control and floodplain management programs are inappropriate or even counter productive in the arid Utah climate. An analysis of the 130-year Utah flood history, the structural and nonstructural flood programs in the state, and local perceptions obtained by field visits and interviews in 35 Utah communities revealed a number of such inefficiencies. Since flood flows dissipate quickly when they emerge from mountain watersheds onto desert lowlands, risks are concentrated near the apex of alluvial fans, include hazard from mud as well as water flow, and are compounded by canal interception of flood waters. Because of variation in the area flooded from one event to the next, floodplain mapping has tended to show risks too high in mapped areas and too low outside. Traditional channelization carries floods downstream past where they would dissipate naturally. The federal government needs to become more active in developing better flood hazard delineation and structural and nonstructural designs for arid areas. State government can help by providing a forum where communities can exchange experiences, reviewing structural designs prepared by local government, and providing local communities with technical expertise for dealing with federal agencies.     

Human urine as a source of alternative natural fertilizer in agriculture: A flight of fancy or an achievable reality

Organically agricultural products are gaining popularities through out the world as it gives the consumer satisfaction with a basket of safer and better trusted foods. It is also well established that intensive conventional agricultural practices can introduce contaminants into the food chain with adverse affect on environment. However, organic agricultural practices give an alternative environmental friendly sustainable agriculture among the farmers. Beside this fact, organic crops contain fewer nitrates, nitrites, pesticide residues and trace elements than conventional crops. Even though, in organic systems generally have 20% lower yields than conventionally produced crops. One of the major constrains of organic farming is decrease of raw organic matters to prepare compost. Therefore, scientists are looking forward for different organic sources which are plenty in nature and available at little-to-no cost. Human urine is one of them, and has been gaining popularities as a raw material for organic cultivation. However, several important merits and demerits of application of human urine are needed to be addressed in agriculture.     

BIOECONOMIC CONSIDERATIONS FOR WASTEWATER REUSE IN AGRICULTURAL PRODUCTION1

ABSTRACT: Urban wastewater can be a valuable source of water and plant nutrients for agricultural producers, particularly in arid regions. The scientific literature reveals cautious optimism concerning the biological, institutional, and economic viability of irrigating crops with secondary-treated effluent. A derived effluent demand function for agricultural producers near Tucson, Arizona, reveals a potential annual demand of 11,000 acre-feet under present price and proposed delivery system conditions. In this case, wastewater could be exchanged for ground water and both the urban and rural areas would gain.     

Socio-Ecological and Religious Perspective of Agrobiodiversity Conservation: Issues, Concern and Priority for Sustainable Agriculture, Central Himalaya

A large section of the population (70%) of Uttarakhand largely depends upon agricultural based activities for their livelihood. Rural community of the mountains has developed several indigenous and traditional methods of farming to conserve the crop diversity and rejoice agrodiversity with religious and cultural vehemence. Traditional food items are prepared during occasion, festivals, weddings, and other religious rituals from diversified agrodiversity are a mean to maintain agrodiversity in the agriculture system. Agrodiversity is an insurance against disease and extreme climatic fluctuations, as a coping mechanism in times of scarcity, as a means to enhance overall productivity of farms, as a source of critical nutrition and medicine in the Himalayan region. The different traditional system of agriculture and indigenous method of maintaining soil fertility, socio-cultural and religious rituals has saved many crops that are under threatened category. But all these system and practices are ignored nauseatingly in hill agriculture policy, where more emphasis was given for plain areas. Less emphasis is being put on local systems that rely on existing natural, human, and social assets such as biodiversity, traditional knowledge, and social capital underpinning collective action to ensure food security. Of late, development planners have realized the importance of appropriate technologies and therefore have stressed the need for on-site training, and capacity building of user groups in rural areas of the region. Rural technology demonstration and training center have been supposed as a means disseminating technologies enabling improvement in the yield potential of farms, income generation from off-farm activities, and conservation and efficient use of natural resources. There is a strong need to bring desirable changes in the agricultural policy, research, and development in reference to mountainous regions. The present paper describe present scenario of agriculture, traditional, and socio-cultural practices of retaining soil fertility and agrodiversity, policy dimensions, and strategies for management of the Himalayan agroecosystems.     

Water resources and development of women in arid regions in northern China

The total land area in China affected by desertification has grown over time due mainly to rapid population growth and environmental degradation. Arid and semi-arid regions now comprise approximately one-third of the country's land area. Women in arid areas suffer from the harsh environment as well as from discriminatory attitudes tied to the general expectations of women's role in society. Discrimination against women, high rates of illiteracy, poor health care, society's failure to recognize women's work, and insufficient social services result in illness, poverty, and low social status among women. The material poverty and lack of knowledge and education among women living in arid areas are discussed, as well as what women can do to alleviate poverty and improve the environment in arid areas. With regard to policies which could lead to sustainable development, the author discusses improving women's education in arid regions, public policies designed to improve women's conditions, ways to involve women in environmental protection, encouraging migration to reduce environmental degradation, and improving childbearing conditions.