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1.
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2.
Farmers' perceptions of soil fertility change were compared with observations on soil quality changes and crop performance in soils from a chronosequence representing a range of soil ages since conversion from forest to cropland (0 to 57 years). A majority of the farmers, 92 per cent, had observed a decline in soil fertility on their land. Farmers use crop yield, indicator plants, soil softness and soil colour to judge soil fertility. They identified 11 plants that they used to indicate high soil fertility and four plants that they used to indicate low soil fertility. There was a strong correlation (r = 0·96) between soil organic matter content (loss on ignition) and farmers' ranking of soil fertility based on colour and softness of soil samples from the chronosequence. The biotest experiment with maize showed an exponential decline in biomass production along the chronosequence, confirming the results of farmers' soil fertility ranking. In the biotest, total soil N predicted produced biomass well (r2 = 0·95), whereas the relationship with soil available P (Olsen) was less obvious. Among the eight analysed plant nutrients in the maize leaves, N content was found to correlate best with biomass production (r2 = 0·94). We conclude (i) that there is good agreement between farmers' knowledge and scientific indicators of soil fertility and (ii) that the major reason for declining soil fertility in Beseku is the decrease in N mineralization over time. Interventions should focus on supporting farmers to implement a diversified nutrient management strategy that can maintain or increase long‐term productivity of the soil. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

3.
Most of Rwanda's wetlands are being reclaimed under government schemes with the aim of growing rice as the main crop. In the present study, information on farmers' knowledge and perceptions of agricultural wetland management was collected in Cyabayaga and Rugeramigozi wetlands. The two wetlands were selected as representatives for typical reclaimed wetland agriculture in Rwanda. They provide contrasts in both environmental and social terms. Three tools were used to investigate farmers' knowledge and perception of agricultural wetland management: (i) household survey; (ii) focus group discussions; and (iii) transect walk. The major constraints identified by farmers in the two wetlands were water shortage and lack of availability of improved seeds and high prices of fertilisers. The primary benefits from wetlands for farmers are income generation in Cyabayaga and food security in Rugeramigozi. The most commonly reported concern about the wetlands in the Cyabayaga and Rugerameragozi was that they are a source of malaria. Rice is an important crop in both wetlands, whereas farmers in Cyabahaga wish to continue cultivating rice, Rugeramigozi farmers prefer to grow rice only after it has been tested for its adaptability. Farmers have sufficient knowledge on the causes and the potential solutions to overcome most constraints. They know that soil suitability is closely related to relief. They classify soils by a number of criteria and choose crops accordingly. Any programme designed to address wetland management in the region will have to take account of farmers' knowledge and adopt a holistic view of wetland management. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

4.
In the Gadarif Region of Sudan, destruction of the natural vegetation for agricultural expansion is one of the major causes of the degradation of renewable resources and the environment. This study identifies and analyses the farmers' attitudes and perceptions towards agricultural land degradation and abandonment. The cross‐sectional data collected from ten key informants and 41 large‐scale farmers focussed on the degradation and abandonment of mechanized agricultural land. The results of the study show that the respondents are well aware that soil degradation is in various forms are taking place on their cultivated agricultural land. This is based on their perception and interpretation of indicators such as weed infestation, poor soil fertility and soil compaction. Continuous cropping, mono‐cropping, rainfall shortage and the use of inferior seeds are the main reasons of land degradation as indicated by farmers. The main measures acknowledged to maintain and improve land productivity are repeated soil ploughing, abandonment/fallow periods and crop rotation. The study adduces evidence of widespread land degradation. The mitigation measures followed by the farmers may though not be sufficient to restore the soil fertility. The application of appropriate chemical fertilizers, sound crop rotation and long fallow periods can be recommended. Any management and research intervention regarding the problem of land degradation should; however, be concerted with the farmers' knowledge. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

5.
Soil quality (SQ) assessment from farmers' point of view can be used as a primary indicator for planning sustainable agriculture. Despite this fact, limited information is documented with regard to SQ indicators, for example weed species, crop types and management practices from farmers' knowledge perspectives. The aims of this study are to analyse factors that determine farmers' knowledge of SQ, identify SQ indicators of weed species and crop types across different SQ status and assess soil‐and‐crop management practices that maintain SQ in the Mai‐Negus catchment, northern Ethiopia. Fifty‐two farmer household heads were chosen randomly for questionnaire interview. The results showed significant (p ≤ 0·05) differences in the proportion of respondents who used different crop‐and‐soil management practices. The success of overall prediction by the logistic regression model (model χ2 = 0·84, p < 0·01) and level of model correct predictions (86%) indicated that the explanatory variables have sufficiently explained farmers' knowledge of SQ indicators. Provided that other conditions remained constant, the odds ratio of variables such as farmer experience, access to information, farm location, education, field slope and land tenure have significantly increased the likelihood of farmers for being knowledgeable of SQ indicators. This study also demonstrated that most farmers are knowledgeable in identifying weed species, crop types and management practices across various SQ status, which suggests that such SQ indicators should be used to assess SQ status (degradation severity) while locating fields to be intervened using appropriate management strategies. © 2013 The Authors. Land Degradation & Development published by John Wiley & Sons, Ltd.  相似文献   

6.
Under the harsh conditions prevailing in the West African Sahel, farmers must deal with a range of environmental and socio-economic issues that constrain agriculture. Although scientific evidence indicates that wind erosion is potentially a major land degradation process, little is known about the Sahelian farmer's perception of the relative importance of wind erosion as a constraint to agricultural production. A village-level survey was therefore undertaken to assess farmers' views about the relative importance of perceived constraints to agricultural production in 41 villages across Niger. During the interviews, the communities' views were also recorded regarding the causes and consequences of wind erosion as well as known wind erosion control measures. Wind erosion ranked eighth overall and was listed by male farmers among the top 10 constraints in 54 per cent of the villages. It was perceived by male farmers to be a moderate to high constraint in 39 per cent of the villages but was not considered important by female farmers. Wind erosion ranked third among environmental constraints, behind drought and soil fertility. Wind erosion related health problems were generally of more concern than crop damage or loss of topsoil by wind erosion. Deforestation, removal of crop residue and land-clearing practices were identified by farmers as major contributors to soil losses by wind. To address this issue, at least 10 different low-cost technologies are currently being implemented by farmers, including leaving crop residue in the field, mulching and natural regeneration of vegetation. The survey results indicate that farmers are well aware of the overriding importance of their management practices, as opposed to climatic factors, on the current extent of wind erosion. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

7.
Despite decades of soil and water conservation (SWC) efforts in Tanzania, the adoption of the recommended SWC measures by farmers is minimal. In the past, SWC plans did not incorporate farmers' knowledge, and the economics of SWC was not given much attention at the planning stage. This research evaluated the applicability of two tools for participatory soil erosion mapping using farmers' indicators of soil erosion and financial analysis of SWC measures at the planning stage. The two tools were evaluated in Kwalei catchment in the West Usambara highlands, Tanzania. The participatory soil erosion‐mapping tool uses farmers' indicators of soil erosion to identify, classify and map soil erosion at the catchment level. The financial analysis tool involves farmers in a stepwise analysis of the costs and benefits of SWC measures before the implementation. The erosion‐mapping tool increased farmers' awareness on the severity of soil erosion problems, and they realised the need for SWC plans at both field and catchment scales. With the financial analysis tool farmers participated in the cost and benefits analysis and were able to select SWC options that were feasible under their socio‐economic situation. The two tools were able to demonstrate that farmers' participation in SWC planning increases the acceptance of SWC measures because they solve problems that are perceived by themselves. The financial analysis tool demonstrated how farmers could make selection of SWC measures that are feasible under their biophysical and economic condition if they are informed about the costs and benefits. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

8.
Amidst growing concerns about farmlands conservation, this paper examines the status of farmlands in two mountain watersheds ‘with’ and ‘without’ external intervention, located in the western hills of Nepal. Information was obtained from a household survey and group discussions conducted during April to September 1999. The severity of soil erosion from farmers' perspectives, density of landslides, soil nutrient balance and change in crop yield have been adopted as indicators of the status of the land. Results of the analysis indicate that land resources in both watersheds are undergoing degradation, though the causes and extent of degradation vary from one type of land to another. Upland crop terraces, locally called bari, are undergoing degradation most seriously under the combined influence of severe soil erosion, landslide and the depletion of soil nutrients. In particular, soil erosion has severely affected nearly half of the upland crop terraces in both watersheds due to a number of natural and anthropogenic factors ranging from weak geological structure to arable agriculture. Landslide and nutrient depletion have affected all types of farmlands except homesteads in both watersheds. Overall, the extent and intensity of land degradation is relatively high in the non‐project area, as farmers were not provided with necessary technical and financial support. A broad strategy has been outlined for effective conservation of farmlands. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

9.
Land degradation is the major economic and environmental threat in Ethiopia. Since the 1960s, the various traditional land management systems have undergone unprecedented changes. Within the context of farmers' awareness of land degradation and local responses to the problems, the objective of this study is to examine the resilience and stability of traditional land management knowledge in Southern Ethiopia. Data were collected using interviews, group discussions and field observations. Results of the study demonstrate that farmers have a wealth of experience in identifying the severity, dynamics and causes of soil erosion and soil fertility decline and grazing land deterioration. In response to these problems, farmers have developed a wide range of traditional land management practices, supported across the generations by the traditional law (benee woga) and norms. However, recent changes include reduction and abandonment of fallowing, modification of crop rotation and large‐scale reduction of manuring. The current practices used to fulfil livelihood requirements are the main driving forces that affect the resilience of the system. Thus, environmental and land use management planning should consider rehabilitating land not only based on traditional land management knowledge but also with regards to raising its agricultural productivity. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

10.
Soil erosion is one form of land degradation, which is caused by the interacting effects of numerous factors such as biophysical characteristics and socio‐economic condition of a particular watershed. Previous erosion studies focused on the use of soil erosion models (e.g. USLE, EUROSEM, SLEMSA etc.), which have been developed under local conditions (e.g. United States, Europe, Africa, etc) and mostly use only biophysical factors as inputs to the models. In this study, a methodology that integrates both biophysical and socio‐economic aspects into a framework for soil erosion hazard assessment using principal component analysis (PCA) is described. The analysis is done at the land unit level. With the particular conditions of the study area that is characterized by Inceptisols and Alfisols soil types, nine different land uses with mixed vegetation and forest area dominant in the steep slope, high annual rainfall (>2500 mm), high population with mostly low income and low education, were considered. These were used in formulating a soil erosion hazard index (EHI) equation which relates a number of key factors consisting of biophysical and socio‐economic variables, namely soil texture, slope steepness, land cover, soil conservation practices, income and farmers' knowledge. Weighting and scoring of these key factors were used to develop the EHI equation and to calculate an index value of erosion hazard for every land unit. Results indicate that more than 60% of the area has erosion hazard ranging from moderate to very severe, and most of the land units with high erosion hazard were found at the mountain areas. It was also found that erosion hazard was severe in areas with high silt content, followed by high rainfall and steep slope, low crop cover without any soil conservation practices coupled with lack of awareness on soil erosion and low income. The key factors identified and level of erosion hazard obtained can be used to formulate conservation measures in critical areas which are prone to soil erosion. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

11.
This paper investigates farmers' perceptions of soil erosion and how it affects crop yields, land values, and private conservation investments in India's semiarid tropics. It is based on three types of data: (1) a survey of farmers in three study villages; (2) a plot survey by a professional soil surveyor in the same villages; and (3) experimental and simulated data from nearby research stations with similar conditions. Farmers' perceptions of erosion are compared to the surveyor's using kappa, a statistical measure of interrater agreement. Perceived erosion–yield relationships are estimated econometrically and compared to experimental and simulated data. Effects on land values and conservation investments are estimated econometrically. Findings suggest that farmers are keenly aware of rill erosion but less aware of sheet erosion; kappa values ranging from 0 to 0·28 suggest low agreement with the soil surveyor. They anticipate annual yield losses of 5·8–11 per cent due to rill erosion; these figures are reasonably consistent with those from nearby research stations. They anticipate yield increases of 3·8–14·5 per cent due to installation of soil conservation bunds, largely because they can harvest soil from up the slope and capture organic matter. Perceived erosion has some effect on land values and soil conservation investments, but other factors such as irrigation and soil type have a much greater effect. These findings suggest that promoting soil conservation requires capitalizing on farmers' interest in short‐term gains, such as from water and nutrient management. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

12.
Despite several approaches that aimed at mobilising East African farmers to embrace soil and water conservation (SWC) activities, farmers hardly responded since they were seldom involved in the planning of SWC activities. Two tools that employ farmers' participation were developed and applied at Gikuuri catchment in Kenya. The first tool involved farmers to map soil erosion using their own indicators and determine the soil erosion status at catchment scale. This formed the basis upon which they undertook to plan for SWC measures at catchment scale. Farmers also predicted crop yield losses based on the soil erosion status. Farmers widely approved the soil erosion status map since their own indicators and perceptions were used. The second tool provided cash flow trends for a variety of SWC activities and farmer situations. Farmers can use land with a high, moderate or low erosion status and often have rather different socio‐economic settings. The net benefits over 5 yr for bench terraces, fanya juu terraces and grass strips were illustrated to assist farmers in making informed decisions on SWC adoption. The two tools increased awareness on the need for collective actions among farmers and showed fields that cause run‐on on downslope fields. The improved awareness of erosion problems and the related financial consequences increased farmers' willingness to share the investment costs for cut‐off drains. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

13.
The prevention of soil erosion is one of the most essential requirements for sustainable agriculture in developing countries. In recent years it is widely recognized that more site‐specific approaches are needed to assess variations in erosion susceptibility in order to select the most suitable land management methods for individual hillslope sections. This study quantifies the influence of different land management methods on soil erosion by modelling soil loss for individual soil‐landscape units on a hillslope in Southern Uganda. The research combines a soil erosion modelling approach using the physically based Water Erosion Prediction Project (WEPP)‐model with catenary soil development along hillslopes. Additionally, farmers' perceptions of soil erosion and sedimentation are considered in a hillslope mapping approach. The detailed soil survey confirmed a well‐developed catenary soil sequence along the hillslope and the participatory hillslope mapping exercise proved that farmers can distinguish natural soil property changes using their local knowledge. WEPP‐model simulations show that differences in soil properties, related to the topography along the hillslope, have a significant impact on total soil loss. Shoulder and backslope positions with steeper slope gradients were most sensitive to changes in land management. Furthermore, soil conservation techniques such as residue management and contouring could reduce soil erosion by up to 70 percent on erosion‐sensitive slope sections compared to that under tillage practices presently used at the study site. The calibrated model may be used as a tool to provide quantitative information to farmers regarding more site‐specific land management options. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

14.
Tillage in Australia has evolved from ‘imported’ European practices to tillage systems more in tune with ‘older’ fragile soils and more severe climatic conditions. Cereal yields are commonly limited by water supply and the native fertility of many soils is poor. Crop/pasture rotations involving pasture legumes have been the mainstay of cereal production in the winter rainfall areas while production in much of the summer rainfall area has relied more on exploiting native fertility. Soil erosion and structural decline are still considered major issues facing long-term production. The general trend in tillage methods is for less tillage and greater retention of crop residues for soil and water conservation.

Tillage experiments have shown that management strategies involving retention of crop residues (stubble), reduced tillage and crop rotation can reduce erosion and improve yield. Results from experimentation are highly variable, both in magnitude and direction of responses to tillage treatments. Much of this variation is due to variation in seasonal conditions. Simulation models are being used to examine management options and to design experiments based on a knowledge of climate variability and physical and biological processes.  相似文献   


15.
中国水土流失防治任务仍然繁重,有计划分批次实施水土流失治理是现阶段条件下的必然选择,优先治理小流域识别是其首要解决的一项基础工作,然而目前相关成果较为缺乏,难以支撑小流域水土流失治理智能决策和精准施策。在当前大力推进智慧水土保持背景下,积极探索优先治理小流域识别方法非常迫切,对于科学、合理、高效促进水土流失治理工作具有重要意义。该研究立足于小流域自然禀赋条件,以中国水土流失重点区域——三峡库区秭归县为例,坚持科学性和可操作性相结合原则,以水土流失“减量和降级”双重目标和治理效益最大化需求为导向,综合水土流失面积和土壤侵蚀强度两个维度,提出小流域水土流失治理优先度定义及定量评价方法,为识别优先治理小流域提供科学依据和技术支撑。结果显示,秭归县2021年现状水土保持率为69.12%,远期（2050年）水土保持率为81.74%,总体提升12.62个百分点。秭归县2021年全域土壤侵蚀模数现状为758.50 t/(km2·a),最小可能土壤侵蚀模数为408.71 t/(km2·a),总体下降比例达46%。秭归县大部分区域均具有较大的水土保持率提升潜力和土壤侵蚀控制度,可完全治理和可降级的水土流失地块分布较为广泛,尤其在县域中西部的小流域存在较大的水土流失面积消减和土壤侵蚀强度降级空间。秭归县各小流域水土流失治理优先度的空间分布总体呈现中部高,东部和南部相对较低的分布格局,全县治理优先度大于0.6的小流域占总全县小流域的11.76%。通过典型县应用,该研究提出的小流域治理优先度涵盖了水土流失面积和土壤侵蚀强度两个维度,能更为全面满足小流域水土流失“减量和降级”双重目标和和治理效益最大化需求,直观反映了水土流失面积消减空间和土壤侵蚀强度降级空间的目标和相对大小,对支撑小流域治理决策更加准确、科学,治理优先度评价方法不仅可行,且易操作。  相似文献   

16.
Maize production in Swaziland's middleveld is being increasingly threatened by the Striga asiatica weed (also called witchweed). It parasitises the maize crop to provide itself with water and nutrients, preventing the crop from growing properly. In this paper we examine the impacts of this bio‐indicator of land degradation on rural livelihoods, investigating how farmers and policy makers are responding to the problem. Our results show that farmers' ability to control weed infestations is determined by a number of environmental, social and political‐economic drivers and that national policies to reduce land degradation offer little assistance. Low‐technology methods employed by farmers are an important step in alleviating the problem, but farmers' understandings of why these methods work are limited and they often neglect to combine control strategies. At the local level, there is a need to support farmer‐to‐farmer learning and education programmes to broaden and deepen farmer knowledge about S. asiatica. At the national level a more supportive policy context is necessary that recognises weeds as an indicator of a more serious overall land degradation problem, and which uses broader criteria to determine what constitutes land degradation. Without this attention, the threat from S. asiatica could increase in both area and intensity, with profound effects on both food security and the sustainability of rural livelihoods. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

17.
Abstract

Cultivated lands in erosion prone agro-ecologies incessantly experience a substantial loss of productive soil and organic matter. Currently, the fertility-management and rainwater-conservation practices are given emphasis separately. This study appraised collectively both the water-conservation and fertility-management practices for the restoration of soil productivity in eroded farmlands. Field experiments were carried out on wheat (Triticum aestivum L.) and maize (Zea mays L.) in eight farmer fields. Four fields of Missa soil series (Typic Ustochrept) and four of Rajar soil series (Typic Ustorthent) were selected. Treatments in each field were: farmers' practice as control without soil-water conservation, and with farmers' rate of fertilizer (per hectare 40 kg N + 30 kg P2O5); improved fertilization (per hectare 100 kg N, 60 kg P2O5, 2 kg Zn, and 1 kg B) without soil-water-conservation practices; soil-water-conservation practices (deep plowing, bund improvement, ploughing across the contour) + farmers' rate of fertilizers; and soil-water conservation + improved fertilization. Crop grain yields were at the highest with soil-water conservation + improved fertilization (per hectare wheat 3.31 Mg and 1.65 Mg in 2004–2005 and 2005–2006; and maize 4.55 Mg and 4.19 Mg in 2005 and 2006, respectively). The lowest yields were recorded under farmers' practice for both crops. Similar was the response for water-use efficiency and plant uptake of nitrogen, phosphorus, zinc, and boron. Missa soil series was more responsive than was Rajar to integrated soil-management practices. Synergistic application of soil-water conservation and improved fertilization practices significantly improved the crop yields, nutrient uptake, and water-use efficiency.  相似文献   

18.
坡耕地不同水土保持措施下的养分平衡和土壤肥力变化   总被引：8，自引：1，他引：8  
在贵州省罗甸县坡耕地上布置长期定位试验 ,研究几种水土保持措施对作物产量和土壤肥力变化的影响。9年的测试结果表明 ,在旱坡耕地上 ,水土流失是造成坡地地力下降、养分损失 ,的主要原因。未采用水土保持措施的坡地种植 ,因水土流失产生的全氮、全磷、有效钾损失 ,分别占总养分消耗量的 5 3.0 % ,6 7.6 %和 19.0 % ,相当于施入土壤的氮素化肥 ,施入的有机和无机磷素 ,有机质的损失与施入的有机肥中有机质含量相当 ,土壤全氮、有机质和有效钾含量趋于下降 ,全磷维持在较低的水平。采取水土保持措施后 ,这些土壤养分可维持平衡或在土壤中逐步积累 ,试验中的植物篱水保处理 ,9年玉米产量平均增产 8.6 % ,并趋于逐年上升。长期的试验证明 ,采用适宜的水土保持措施可提高地力 ,增加产量 ,实现坡耕地的可持续利用  相似文献   

19.
[目的]了解农户自身行为对水土流失影响,为保护和改善粤北山区生态环境、实现精准贫困和区域可持续发展提供依据。[方法]以贫困胁迫下的粤北山区农户行为为研究对象,采用参与式农村评估(PRA)进行农户调查,并通过"压力—状态—响应(PSR)"模型建立粤北山区农户行为对水土流失影响评价指标体系,从农户行为视角出发,结合层次分析法确定各指标权重,定量评价农户行为对水土流失影响程度。[结果](1)由于薪柴依赖度降低、坡耕地比重下降等因素,2012—2016年农户行为对水土流失影响的压力值逐渐降低;(2)虽然农户区水土流失状态值降低,但农户水土保持状态增加,总状态值稍有增加;(3)农户和政府对水土流失治理响应值逐渐增加;(4)综合PSR值,最终农户行为对水土流失影响值稍微降低,生态环境有所好转。[结论]粤北山区农户对水土流失影响压力值降低,状态值增加,最终农户行为对水土流失影响值稍有降低,农户行为对水土流失影响减小。  相似文献   

20.
土壤结构是土壤肥力的物质基础,水土流失等导致土壤结构退化成为威胁我国粮食安全的重要因素。本文利用8年田间定位试验,通过土壤切片技术,研究不同农田恢复措施(耕作和有机物料投入)对黑土母质发育的新成土壤团聚体微形态的影响,对理解成土过程和肥力快速恢复具有重要意义。结果表明:免耕土壤(自然、人工植被恢复)、不施肥耕作土壤和仅施化肥耕作土壤均为复合孔洞状微结构,主要孔隙形状均为面状或孔洞状,连通性及数量相当,土壤垒结和微结构类似;但土壤颗粒分布频度和均匀度及粗细粒质接触紧密度与耕作负相关,免耕土壤显著地高于耕作土壤(P0.05)。施肥耕作土壤中,施有机物料的土壤为海绵状微结构,施高量有机物料的土壤微结构发育最好,施低量有机物料的土壤微结构次之,不施有机物料土壤微结构最差;其土壤垒结和微结构发育特征与有机物料的投入正相关。  相似文献   

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