Integration of conservation agriculture in smallholder farming systems of southern Africa: identification of key entry points

A component-omission experiment based on the principle of conservation agriculture (CA) was established on smallholder farms for three seasons in Murehwa and Hwedza districts, Zimbabwe; Barue district in Mozambique; Balaka district and Chitedze Research Station in Malawi, and Monze district in Zambia to identify strategies for improving crop productivity and livelihoods for smallholder farmers. The objective of the experiment was to evaluate the effect of tillage, residue retention, fertiliser application and weed control on maize yield. In addition, the study analysed possible combinations of these factors that could provide a sustainable entry point for intensification through CA. Results showed that fertilisation had the strongest effect on crop yield in both tillage systems; adequate fertilisation is therefore key to success in CA. Retention of crop harvest residues increased yield in no-tillage systems; no-tillage without residues depressed yield by 50% when compared with yields of conventional tillage. A step-wise integration of CA into the smallholder farming systems is proposed as a possible strategy to avoid new constraints on smallholder farms. If resources are limiting, farmers may apply all principles on small areas to overcome the initial demand in resources (labour, fertiliser and residues), and once productivity is raised, they can expand.     

A comparative multidimensional evaluation of conservation agriculture systems: A case study from a Mediterranean area of Southern Italy

To avoid the current paradoxes of the global agro-food system it is necessary to define and implement a viable agricultural sustainable model, combining satisfaction of food needs and land preservation. A possible solution can be found in a holistic production system consistent with a sustainable development model, designed to satisfy diverse “local” economies. The conservation agriculture (CA) could be a part of this model, as it includes a set of best practices available to preserve agrarian soil and its biodiversity. Briefly, we cover the CA background in Europe followed by the evaluation of its impact in terms of private/public interest, using the sustainability’s metric.To test the viability of a model based on CA in “local conditions”, we compare economic performance of different conservation practices (i.e. minimum and no tillage) to that of conventional agriculture in a typical Mediterranean environment – Collina Materana – in Southern Italy (Basilicata region). Our findings suggest that: i) CA can actually be a viable alternative to conventional systems; ii) in Mediterranean agricultural areas CA has yield advantages especially during dry years, when conservation techniques increase water supply to crops; iii) public support is needed to direct farming choices in fact without financial incentives these practices would be not widely accepted and diffused; iv) European policy makers have to recognized the positive benefits of CA and pay them as ecosystem services in the framework of Good Agricultural Environmental Conditions and the present CAP subsidies.     

Intensification of conservation agriculture systems for increased livestock feed and maize production in Zimbabwe

Livestock and crops are key components of mixed farming systems and are a source of household food and income. However, mixed farming systems face livestock feed shortages and low soil productivity challenges. Conservation agriculture (CA) systems based on minimum soil disturbance, crop residue retention and crop rotations offer an opportunity to grow both fodder and food crops on the available land to improve productivity and crop output per-unit area. A four-year experiment involving maize monocropping as control treatment and four relay or intercropping treatments with different legume and fodder crops was set up on contrasting soils in Zimbabwe. Lablab was superior in biomass production compared with radish on both soil types. On the clay soil, continuous maize, sole lablab, sole radish, maize/lablab relay and radish/common beans relay treatments produced similar biomass when soil moisture was adequate. When soil moisture was limiting, lablab produced more biomass than continuous maize, radish, maize/lablab relay and radish/beans relay treatments on clay soil. On sandy soils, lablab produced more biomass than continuous maize, radish, maize/lablab relay and radish/beans relay treatments. Leguminous and non-leguminous fodder crops can be grown successfully in CA systems that are being promoted in the mixed crop/livestock farming systems of southern Africa.     

Further participatory adaptation is required for community leaders to champion conservation agriculture in Africa

There is a recognized need for the participation of local communities in designing and implementing agricultural interventions for the sustainable intensification in smallholder systems. This study examines the perspectives of local community leaders towards the widely promoted, but not widely adopted, practice of Conservation Agriculture (CA) in African smallholder systems. Perceptions from 47 community leaders (both from traditional local authorities and farmer organizations) across six African countries are documented regarding how CA matches the wants, needs and capabilities of farmers in their communities. While community leaders generally perceived CA as potentially beneficial, they also indicated that CA is not currently perceived as feasible within their communities and hence has limited relevance. Three key themes were identified that limit both CA use and sustainable intensification more generally: [1] a perceived reluctance of farmers to engage with the community platform as part of a higher input, market-oriented production system; [2] informational constraints due to non-functional exchange mechanisms; and [3] a lack of local adaptation of CA underscored by the persistence of top-down, linear research and extension approaches. Through greater understanding of local perspectives, a clearer picture emerges of the need for greater participatory engagement and local adaptation if sustainable intensification of African smallholder agricultural systems is to be achieved.     

Awareness and adoption of conservation agriculture in Malawi: what difference can farmer-to-farmer extension make?

Despite the potential of conservation agriculture (CA) for increased crop yields, energy savings, soil erosion control, and water-use efficiency, smallholder farmers in sub-Saharan Africa have been slow to adopt. Farmer-to-farmer extension (F2FE) may have a role to play in overcoming the information access problems and lack of knowledge that may preclude widespread adoption. This study uses data for 180 lead farmers linked to their 455 followers to investigate how F2FE influences awareness and adoption of CA technologies in Malawi. Results from a bivariate probit model for follower farmer awareness and adoption of the three CA principles (minimum soil disturbance, crop residue retention, and crop diversification) reveal four main findings: First, lead farmer motivation increases their effectiveness at diffusing CA practices to their followers. Second, lead farmer familiarity with and adoption of CA both matter to the spread of CA practices, but familiarity appears more important. Third, lead farmers play a more critical role in increasing awareness than adoption of the CA practices. Finally, F2FE is a complement rather than a substitute for other sources of agricultural extension in Malawi's pluralistic extension system and should support but not replace current systems. Research and policy implications are discussed.     

Can improved agricultural technologies spur a green revolution in Africa? A multicountry analysis of seed and fertilizer delivery systems

Sub‐Saharan Africa faces low agricultural productivity amid a confluence of trends that include rapid population growth, climate change, and the rise of the middle class. To raise productivity, governments—in partnership with donors and development organizations—have launched numerous initiatives to encourage the development of sustainable and competitive agricultural input markets. Despite these efforts, markets remain underdeveloped in most countries and access to affordable seeds and fertilizers remains a major challenge for smallholder farmers. This paper explores evidence from recent multicountry analyses of input delivery systems to assess the possibility of a Green Revolution in Africa. It describes use and adoption levels, challenges, policy and regulatory issues, and investments needed to expand smallholder access to these productivity‐enhancing agricultural technologies.     

The spread of Conservation Agriculture: justification,sustainability and uptake

Conservation Agriculture (CA) has been practised for three decades and has spread widely. We estimate that there are now some 106 million ha of arable and permanent crops grown without tillage in CA systems, corresponding to an annual rate of increase globally since 1990 of 5.3 million ha. Wherever CA has been adopted it appears to have had both agricultural and environmental benefits. Yet CA represents a fundamental change in production system thinking. It has counterintuitive and often unrecognized elements that promote soil health, productive capacity and ecosystem services. The practice of CA thus requires a deeper understanding of its ecological underpinnings in order to manage its various elements for sustainable intensification, where the aim is to optimize resource use and protect or enhance ecosystem processes in space and time over the long term. For these reasons CA is knowledge-intensive. CA constitutes principles and practices that can make a major contribution to sustainable production intensification. This, the first of two papers, presents the justification for CA as a system capable of building sustainability into agricultural production systems. It discusses some of CA's major achievable benefits, and presents an overview of the uptake of CA worldwide to 2009. The related paper elaborates the necessary conditions for the spread of CA.     

提升农业可持续生产力的瓶颈问题与对策

[目的]解决长期以来我国农业生产力的提升主要围绕产量展开带来的资源问题、环境问题和生态问题,突破农业生产力提升的不可持续性和空间有限的困境,从而有效促进农业可持续发展。[方法]理论分析推导,实践归纳总结,政策引领分析。[结果]农业是与自然关系密切的产业,农业可持续生产力的提升也必须从资源、环境和生态这些方面寻找根本驱动力,紧紧围绕资源节约型、环境友好型、生态保育型"三型"农业展开。[结论]提升农业可持续生产力要突出3个创新:(1)体系创新,即用生物农业和物理农业构建高效生态农业体系,以逐步替代化学农业;(2)产业创新,即以建立在农业废弃物循环经济基础上的静脉产业促进生产农产品的动脉产业,形成高盈利静动脉产业联合体;(3)模式创新,即创建高效生态农业特效模式,为提升农业可持续生产力找到特效路径。     

Feasibility of conservation agriculture in the Amu Darya River Lowlands,Central Asia

Human-driven land degradation threatens economic and environmental sustainability of irrigated agricultural production such as in Central Asia. Many current challenges can be eased by implementing Conservation Agriculture (CA), with however unknown financial consequences under the predominating irrigated conditions. We applied the linear programming to compare costs and benefits of four CA production systems, which are cotton-based rotation systems including (i) cotton-cotton and (ii) cotton-wheat-maize rotations under conventional tillage (CT), as well as (iii) cotton-cover crop-cotton, and (iv) cotton-wheat-maize rotations with mulch cover (crop residue retaining) and both rotations under permanent-bed planting (PB) with minimum tillage. All systems were subjected to six levels of land quality and a series of crop pricing schemes. Data were extracted from empirical research on CA in Uzbekistan, complemented with data on input and output prices from surveys. The findings underpinned the financial advantages of more diversified cropping systems (cotton-wheat-maize) over the crop monoculture (cotton-cotton-based system). Crop cultivation on marginal land was unprofitable under CT. In contrast, crop production under PB could generate profits even on croplands with a lower productivity level considered. It is argued that PB with crop residue retaining and applied in cotton-wheat-maize rotation shows most promise for improving crop yields and income.     

Nonfarm employment,agricultural intensification,and productivity change: empirical findings from Uganda

This article uses panel data from the Living Standards Measurement Study‐Integrated Surveys on Agriculture for Uganda to assess the farm‐level effects of nonfarm employment on agricultural intensification and productivity change. A sample selection model is used to account for both unobserved heterogeneity and potential simultaneity between agricultural production and nonfarm income. Results show that nonfarm employment can have differential impacts on farm technology intensity and productivity. Nonfarm income is found to have a positive impact on farm hired labor and improved seed intensity; a negative effect on on‐farm family labor use; and no significant impact on fertilizer, soil water management, and joint use of farm technologies. The econometric evidence also indicates that agricultural productivity declines as nonfarm income increases. Taken together, our findings reveal important trade‐offs between nonfarm employment and income and farm productivity growth under smallholder agriculture. The results indicated that targeted policies are required to reduce these potential trade‐offs between nonfarm employment and agricultural intensification and productivity change.     

Environmental discounting behaviour of smallholder farmers in Chibombo District,Central Zambia

This study utilised 158 semi structured interviews, three focus group discussions and two key informant interviews to achieve its aim of investigating environmental discounting by smallholder farmers in Chibombo, Zambia. Results suggest that most smallholder farmers were willing to continue using mineral fertilisers in the short to medium term even when they were told there could be potentially negative effects as a result. This result was attributed to the farmers’ experience with neutralising soil acidity through lime application and crop rotations. The proportions of smallholder farmers who would continue using pesticides increased with the period it takes for pesticide induced soil infertility to manifest. The respondents seemed more concerned about effects on the soil that would manifest in five years. Smallholder farmers preferred soil improving practices with short term benefits, and low risk. The proportions of smallholder farmers willing to plant fertiliser trees reduced from 68.5 % when the benefits accrue in five years to about 38 % when said benefits accrue to the next generation. Study recommends that agricultural development interventions should focus on low risk, locally available technologies with shorter term benefits and minimal future costs. Study recommends that agricultural development interventions include innovation of practices with shorter term benefits, minimal future costs and farmer sensitisation on the benefits of sustainable agriculture.     

Smallholders,institutional services,and commercial transformation in Ethiopia

This article examines the role of institutional services of credit, input supply, and extension in the overall commercial transformation process of smallholder agriculture in Ethiopia. Survey data collected in 2006 from 309 sample households in three districts of Ethiopia are used for the analyses. Tobit regression models are used to measure the effect of access to services on the intensity of inputs use for fertilizer and agrochemicals. A probit model is used to measure these effects on the adoption of improved seeds. Intensity of use of seeds is analyzed using an ordinary least squares model. Logarithmic Cobb–Douglass functions are estimated to analyze the effect of access to services on crop productivity. Heckman's two‐stage estimation is used to examine determinants of household market participation and the extents of participation. Results show that access to institutional support services plays a significant role in enhancing smallholder productivity and market orientation. Our results imply that expanding and strengthening the institutional services is critical for the intensification and market orientation of smallholder agriculture in Ethiopia. In particular, appropriate incentives and regulatory systems are urgently needed to encourage the involvement of the private sector in the provision of agricultural services.     

Negative evaluation of conservation agriculture: perspectives from African smallholder farmers

Despite more than three decades of promotion, conservation agriculture (CA) has not been widely adopted by smallholder farmer in sub-Saharan Africa. This low rate of adoption reflects substantial negative evaluation of CA by many smallholder farmers, the causes of which have not been adequately explored in an in-depth, qualitative manner. Hence, we implement the Livelihoods Platforms Approach to explore directly with negatively evaluating farmers the reasons why they chose not to implement CA using semi-structured interviews with 35 farmers from 23 communities in 6 African countries. While there are issues with perceived benefit and relevance, the primary driver of negative evaluation of CA was found to be the feasibility of implementation. The required resources to implement CA (financial, physical, human and informational) are limited by community and institutional constraints which appear unlikely to be overcome through interventions targeted at addressing household resources. More positive evaluation of CA by smallholder farmers requires: (1) development of financially viable CA adoption pathways; (2) incorporation of wider livelihood objectives into a CA ‘package’; (3) re-evaluation of current extension policy; and (4) development of CA-complementary agricultural policies. Without addressing these issues, the potential benefits of CA adoption are unlikely to be achieved in African smallholder systems.     

滨海滩涂垦区主要大田作物生产碳足迹研究*——以江苏省盐城市为例

[目的]由于自然要素组合的特殊性,与传统内陆农区相比,滩涂围垦区农业生产特点鲜明。摸清该区大田作物碳足迹,可减少区域碳排放,提升农业生产效率,优化区域资源配置。[方法]采用生命周期评价理论结合IPCC田间温室气体计算方法,建立大田作物碳足迹评估模型,估算滨海滩涂垦区大田作物温室气体排量。[结果](1)滨海滩涂地区大田作物的碳足迹(以CO_2当量)总体在0.63～0.769kg/kg范围内,不同作物的碳足迹由大到小依次为:玉米0.769±0.224kg/kg、水稻0.739±0.241kg/kg、小麦0.636±0.183kg/kg和大麦0.630±0.184kg/kg;(2)氮肥生产和施用环节对该区碳足迹贡献度最大,贡献率分别为26.46%～37.12%和29.06%～51.94%。该地碳足迹数值和结构上呈显著地域化特点,与中国其他地区相比,氮肥施用贡献度大,水田灌溉贡献度大。[结论]降低该地区碳足迹,重点关注施氮和水稻灌溉工程两个方面。采用降低施氮量、提高氮肥利用率、发展节水农业与生态农业等措施,可达到降低碳足迹的目的。     

Trade‐offs in the performance of alternative farming systems

Numerous alternative farming systems are proposed as solutions to the sustainability challenges of today's conventional farming systems. In this paper, we review the production, environmental, and socioeconomic performance of three widely discussed and promoted alternative farming systems—organic, smallholder, and urban agriculture. We show that both organic and smallholder agricultures have some benefits, but also entail important trade‐offs; organic has environmental benefits, and also livelihood, health, and nutritional benefits for producers and consumers, but is hampered by lower yields and higher prices. Smaller farms have higher yields and host higher biodiversity, but are hampered by lower incomes to farmers. Urban agriculture can take some pressure off rural landscapes, provide nutritional benefits to the urban poor, and engage urban dwellers in addressing food system challenges, but it simply cannot scale up to be a substantial solution in and of itself. We suggest that instead of focusing on alternative systems, we should identify pathways to sustainable farming for all systems, reforming conventional systems where they perform poorly, and transitioning to alternative systems in contexts where they perform best.     

农业生产效率与其影响因素相关关系实证分析——基于湖北省数据

相对于第二产业与第三产业来说,我国农业发展方面存在的生产效率问题依旧亟待解决,研究农业生产效率及其影响因素对于我国农业经济发展具有深远意义。通过查阅农业生产相关文献,在对农业生产效率内涵及其理论基础进行阐述的基础上,文章构建DEA与Tobit等2种适用于不同情况的评价模型来确定我国农业生产率的影响因素及影响程度;并以湖北省为研究对象,利用湖北省统计数据得出渔业和畜牧业所占比重对农业生产效率影响最大;第一产业相对劳动生产力和农业支出比重越大,农业生产率越高,第二产业相对劳动生产力越大,农业生产率越低;单位机械动力产值、单位灌溉面积以及单位化肥用量越大,农业生产率越高。研究结论对促进经济与农业同步可持续协调增长、推广优势农业以及实现资源最大化利用、提高区域农业生产率均有一定的现实意义。     

Soil and cropping system research in semi-arid West Africa as related to the potential for conservation agriculture

Semi-arid West Africa faces challenges to increase sorghum and pearl millet production to meet food needs for a growing human population while increasing soil carbon (C), nutrient levels, and water holding capacity that are documented benefits of conservation agriculture. This review focuses on the wealth of research on cropping systems, tillage, crop residue, nutrient, and weed management as related to conservation agriculture. It also identifies needs for multidisciplinary, integrative research to assist the transition from current production systems to conservation agriculture. Crop residue use as livestock feed, or fuel are major constraints to adoption of conservation agriculture, which could be reduced by wood production in agroforestry systems, alternate energy sources, and increased forage supply. Crop residue and grain yields are related, thus improved crop, soil, water, nutrient, and weed management to increase grain yield would also increase the supply of crop residue with potential for ‘left over’ crop residue being available for soil mulching. Incorporating indigenous shrubs and/or cover crops could also increase crop residue supply. Species diversity can be increased through crop rotation, agroforestry, cover crops, and intercrops. Higher grain and stover yields and increased profit potential for resource-poor farmers in West Africa will be required before wide-scale adoption of conservation agriculture will be possible.     

Measuring the sustainability and economic viability of tropical farming systems: a model from sub-Saharan Africa

New technologies must be developed in sub-Saharan Africa which are sustainable and economically viable. This paper discusses a methodology for measuring the agricultural sustainability and economic viability of tropical farming systems for new technology evaluation. The approach is based on the concept of interspatial and intertemporal total factor productivity, paying particular attention to valuation of natural resource stock and flows. Agriculture is a sector which utilizes natural resources (e.g. soil nutrients) and the stock and flows of these resources affect the production environment. However, in many cases, the stock of these resources is beyond the control of the farmer and must be accounted for in an agricultural sustainability and economic viability measurement. For example, soil nutrients are removed by crops, erosion or leaching beyond the crop root-zone, or other processes such as volatilization of nitrogen. Agricultural production can also contribute to the stock of some nutrients by leguminous plants such as agroforestry systems. Using a data set available at the International Institute of Tropical Agriculture, we compute the intertemporal and interspatial total factor productivity indices for four cropping systems in southwestern Nigeria using stock of major soil nutrients as the natural resource stock. Results show that the sustainability and economic viability measures are sensitive to changes in the stock and flow of soil nutrients as well as the material inputs and outputs. Where the contribution of natural resource stock and flows are important (such as in the case of alley cropping), the measures provide markedly different results from conventional TFP approaches. The advantage of this approach is that interspatial and intertemporal total factor productivity measures are computed using only price and quantity data, thus eliminating the need for econometric estimation.     

Diversification in Indian agriculture towards high value crops: Multilevel determinants and policy implications

Employing a multilevel model, this paper demonstrates the importance of contextual effects, over and above the compositional effects, in shaping the geographical pattern of agricultural diversification towards high value crops. The results reveal that, besides household-level differences, the contextual effects of higher geographical levels, especially states and villages, explain significant variation in land-use under high value crops, but these do not apply to all types of crops and farm classes in a similar manner. Further, the findings also ascertain that ignoring one or more geographical or administrative levels may yield biased estimates, leading to erroneous conclusions and an incomplete understanding of the geography of agricultural diversification. From a policy perspective, these evidences provide an important feedback for the correct targeting of diversification strategies, their coordination and monitoring at different geographical or administrative levels for efficient, sustainable and inclusive growth of agriculture.     

Farming systems and Conservation Agriculture: Technology,structures and agency in Malawi

Conservation Agriculture (CA) is advocated as an agricultural innovation that will improve smallholder famer resilience to future climate change. Under the conditions presented by the El Niño event of 2015/16, the implementation of CA was examined in southern Malawi at household, district and national institutional levels. Agricultural system constraints experienced by farming households are identified, and in response the technologies, structures and agency associated with CA are evaluated. The most significant constraints were linked to household health, with associated labour and monetary impacts, in addition to the availability of external inputs of fertiliser and improved seed varieties. Our findings show that such constraints are not adequately addressed through current agricultural system support structures, with the institutions surrounding CA (in both Government extension services and NGO agricultural projects) focusing attention predominantly at field level practice, rather than on broader system constraints such as education and health support systems. Limited capacity within local institutions undermines long term efforts to implement new technologies such as CA. It is vitally important that the flexibility of farmers to adapt new technologies in a locally-appropriate manner is not closed down through national and institutional aims to build consensus around narrow technical definitions of a climate-smart technology such as CA. To enable farmers to fully utilise CA programmes, interventions must take a more holistic, cross-sectoral approach, understanding and adapting to address locally experienced constraints. Building capacity within households to adopt new agricultural practices is critical, and integrating healthcare support into agricultural policy is a vital step towards increasing smallholder resilience to future climate change.