Who is resilient in Africa’s Green Revolution? Sustainable intensification and Climate Smart Agriculture in Rwanda

Under the banner of a "New Green Revolution for Africa," agricultural intensification programs aim to make smallholder agriculture more productive as well as "climate smart". As with Green Revolutions in Asia and Mexico, agricultural innovations (hybrid seeds, agronomic engineering, market linkages,and increased use of fertilizer and pesticides) are promoted as essential catalysts of agriculture-led economic growth. Intensification programs are now frequently linked to Climate Smart Agriculture (CSA), which attempts to build resilience and reduce greenhouse gas emissions while increasing crop yields. This article considers who and what is resilient in Africa’s Green Revolution. We report on a multi-season study of smallholder food producers' experiences with Rwanda’s Crop Intensification Program (CIP) and related policies that aim to commercialize subsistence agriculture while implementing CSA. . We suggest that there are fundamental limits to the climate resilience afforded by CSA and development efforts rooted in Green Revolution thinking. Our findings illustrate that such efforts foreground technology and management adjustments in ways that have reduced smallholder resilience by inhibiting sovereignty over land use, decreasing livelihood flexibility, and constricting resource access. We put forth that rural development policies could better promote climate-resilient livelihoods through: 1) adaptive governance that enables smallholder land use decision-making; 2) support for smallholder food producers’ existing agro-ecological strategies of intensification; 3) participatory approaches to visualize and correct for inequalities in local processes of social-ecological resilence Such considerations are paramount for meeting the United Nations Sustainable Development Goals and building climate-resilient food systems.     

Adoption of climate‐smart practices and its impact on farm performance and risk exposure among smallholder farmers in Ghana

Increased climate variability during the last four decades has made the agricultural environment in many developing countries more uncertain, resulting in increasing exposure to risk when producing crops. In this study, we use recent farm‐level data from Ghana to examine the drivers of individual and joint adoption of crop choice and soil and water conservation practices, and how adoption of these practices impacts on farm performance (crop revenue) and exposure to risks (skewness of crop yield). We employ a multinomial endogenous switching regression model to account for selectivity bias due to both observable and unobservable factors. The empirical results reveal that farmers’ adoption of crop choice and soil and water conservation leads to higher crop revenues and reduced riskiness in crop production, with the largest impact on crop revenues coming from joint adoption. The findings also show that education of the household head, access to extension and weather information influence the likelihood of adopting these practices. Thus, enhancing extension services and access to climate information and irrigation can reduce gaps in adoption of soil and water conservation and crop choice, considered as climate‐smart practices that will eventually improve crop revenues and reduce farmers’ exposure to climate‐related production risks.     

Farm-level adaptation to climate change in Western Bangladesh: An analysis of adaptation dynamics,profitability and risks

Using long-term district-level climate data and a case study from a drought-prone village in western Bangladesh, this research explored trends in climate change, and analysed farmers’ adaptation dynamics, profitability and risks. This is the first study of its kind for drought-prone areas in Bangladesh.Farmers perceived climate changes included increases in temperature and decreases in rainfall which were as consistent with the trends of Chuadanga climate records. Farmers’ adaptation measures included changes in cropping systems, cropping calendars, crop varieties, agronomic practices, crop diversification and improved animal husbandry. Reducing environmental stress, ensuring self-sufficiency in staple crops (mainly rice) and other crop production practices, and enhancing economic viability of farm enterprises have underpinned these adaptations. Off-farm and non-farm wage employment, temporary migration, self-employment and educating children, constituted the core non-farm adaptation strategies.Emerging cropping systems like maize/cucumber and maize/stem amaranth/rice were economically more viable than the traditional rice/rice and rice/maize systems. Despite some uncertainties, farming was preferred to off-farm work, generating higher returns to labour for all cropping systems. Limited access to stress-tolerant varieties, extension services and affordable agricultural credit, combined with high production costs, variability in crop yields and output prices, are the main barriers to adaptation. Stronger agricultural research and support services, affordable credit, community-focussed farming education and training are critically important for effective adaptation to climate change.     

The impact of agricultural research in Africa: aggregate and case study evidence

This paper presents case-study results and aggregate data to evaluate the impact of research in African agriculture. Of 32 case studies, all but eight report annual returns over 20% and many are far higher, with most gains arising in the late 1980s and 1990s. Spurred by policy reforms and changing incentives, these innovations have led to sustained growth in aggregate cereal crop yields since 1985. Africa's belated ‘green revolution’ is based on new varieties (often with early maturation for drought escape), complemented by new management techniques (typically labor-intensive efforts to conserve soil moisture and build soil fertility).     

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.     

农业政策调整下大豆种植格局变化对水土资源消耗的影响评估

[目的]通过对政策调整下农作物种植格局变化引起的水土资源消耗变化研究，从资源利用角度为种植格局调整的政策制定提供科学支撑。[方法]文章以黑龙江省为研究区，利用系统动力学方法构建大豆种植格局驱动机制模型，并模拟三大作物(即大豆、玉米和水稻)补贴政策情景下的作物种植面积转换；其次，核算三大作物生产中的水土资源消耗量，并获取不同政策情景下大豆与玉米和水稻种植面积转换引起的水土资源消耗变化量。[结果](1)黑龙江省大豆、玉米和水稻生产过程中单位面积的水资源消耗排序为“大豆<玉米<水稻”，单位产量的耕地资源消耗排序为“水稻<玉米<大豆”。(2)由于单位面积大豆的耗水量最少、单位产量大豆的耕地消耗量最多，当大豆生产者补贴增加40%时，大豆净增加面积最多(由玉米和水稻转入)，因此三大作物生产过程中水资源消耗总量减少最多为2 400万m³，但耕地资源消耗仅增加3.2万hm²。[结论]农业补贴调整，不仅可以满足粮食的总体供给，优化作物种植格局、扩大大豆种植面积，进而减少大豆供给的不确定性，还可以实现区域水土资源的优化配置。该文结论可以为...     

Improving China’s food and environmental security with conservation agriculture†

China has achieved impressive increases in agricultural output in recent decades. Yet, past approaches centred on a growing use of fertilizers, pesticides, fuel and water are not likely to achieve the required 30–50% additional increases in food production by mid-century. We show that efficiencies of production are falling and the costs of environmental harm are increasing. Agricultural innovations that improve natural capital are urgently needed. Conservation agriculture (CA) is now practised on >8?Mha in China and is offering promising prospects of both enhanced yields and environmental services. Our meta-analysis of 60 papers with 395 observations in China shows notable benefits from CA. Mean yield increase was 4.5% or 263?kg?ha^?1 for wheat, 8.3% or 424?kg?ha^?1 for maize, and 1.65% or 250?kg?ha^?1 for rice. In 34 datasets from 22 published papers (experimental duration: 2–17 years), 26 datasets (76.5%) show that CA increased yield and soil organic carbon (mean SOC increase of >3?g.kg^?1 in 0–10?cm soil depth) when compared with traditional tillage. Key priorities for the spread of more sustainable forms of agriculture in China are national policy and financial support, better coordination across agencies, and better extension for farmers.     

Soil,water and crop management alternatives in rainfed agriculture in the Sahel: an economic analysis

Most agriculture in the Sahel Region is carried out under rainfed conditions where low and uncertain soil moisture levels limit productivity. Improved soil, water and crop management practices are required to reverse the steady decline in per capita food production and sustain output over the long term. Several technological innovations and related farm management practices are evaluated in a case study of a typical farm in Mali. Through use of a soil-water balance model and a whole-farm economic model an optimal mix of these measures is identified. Compared to a base case where no modern inputs are utilized, the combination of animal traction (oxen team), low levels of NPK fertilizer, tied-ridges, traditional long-season food grain crops and early planting was most effective: food grain output was 35% higher than with the traditional base case; soil erosion was reduced by 72%; and even with residual future soil erosion damage capitalized into current income, net farm income was larger by a factor of almost 45.     

Sustainable crop intensification through surface water irrigation in Bangladesh? A geospatial assessment of landscape-scale production potential

Changing dietary preferences and population growth in South Asia have resulted in increasing demand for wheat and maize, along side high and sustained demand for rice. In the highly productive northwestern Indo-Gangetic Plains of South Asia, farmers utilize groundwater irrigation to assure that at least two of these crops are sequenced on the same field within the same year. Such double cropping has had a significant and positive influence on regional agricultural productivity. But in the risk-prone and food insecure lower Eastern Indo-Gangetic Plains (EIGP), cropping is less intensive. During the dryer winter months, arable land is frequently fallowed or devoted to lower yielding rainfed legumes. Seeing opportunity to boost cereals production, particularly for rice, donors and land use policy makers have consequently reprioritized agricultural development investments in this impoverished region. Tapping groundwater for irrigation and intensified double cropping, however, is unlikely to be economically viable or environmentally sound in the EIGP. Constraints include saline shallow water tables and the prohibitively high installation and energetic extraction costs from deeper freshwater aquifers. The network of largely underutilized rivers and natural canals in the EIGP could conversely be tapped to provide less energetically and economically costly surface water irrigation (SWI). This approach is now championed by the Government of Bangladesh, which has requested USD 500 million from donors to implement land and water use policies to facilitate SWI and double cropping. Precise geospatial assessment of where freshwater flows are most prominent, or where viable fallow or low production intensity cropland is most common, however remains lacking. In response, we used remotely sensed data to identify agricultural land, detect the temporal availability of freshwater in rivers and canals, and assess crop production intensity over a three-year study period in a 33,750 km² case study area in southwestern Bangladesh. We combined these data with georeferenced and temporally explicitly soil and water salinity information, in addition to relative elevation classifications, in order to examine the extent of winter fallows and low productivity rainfed cropland that could be irrigated by small-scale surface water pumps. Applying observations of irrigated crop sowing dates and yields from 510 wheat, 550 maize, and 553 rice farmers, we also modeled crop intensification production scenarios within the case study area. We conservatively estimate that at least 20,800 and 103,000 ha of fallow and rainfed cropland, respectively, could be brought into intensified double cropping using SWI. Scenario analysis indicates that if 25%–75% of the fallow or low-intensity land were converted to irrigated maize, national aggregate production could increase by 10–14% or 29–42%, respectively. Conversion to wheat would conversely boost national production by 9–10% or 26–31%. Irrigated rice is however unlikely to contribute >3%. In aggregate, these actions could generate between USD 36–108 million of revenue annually among farmers. Intensification therefore has important land use policy and food and income security implications, helping to rationalizei SWI investments. Crop choice, water resource allocation, and water governance will however remain crucial considerations for irrigation planners.     

Assessing the potential of SRI management principles and the FFS approach in Northeast Thailand for sustainable rice intensification in the context of climate change

The paper describes the facilitated learning process of farmers, its results and implications in addressing the low productivity of Jasmine rice in northeast Thailand using the SRI-FFS approach in a collaborative action research. Other involved included rice traders, millers, researchers, government and non-governmental organizations. Working through an inclusive process of dialogue, observation, diagnosis, experimentation and exposure to different types of innovative agronomic crop management (IACM) practices resulting from the SRI–FFS approach, participants made a thorough analysis of the current management practices and evaluated various IACM practices for their productivity and profitability. The results confirmed the potential of IACM in enhancing crop and water productivity along with soil fertility with relatively low input-use (seed, water and fertilizers) and higher net farm-income compared to existing crop management practices. However, factors such as (i) the age of the farmers and (ii) off-farm employment opportunity are key drivers that affect the crop management decision-making process. Therefore, exploration of value-added production alternatives and favourable policies is required to sustain IACM that can benefit farmers, consumers and the environment. The participation of policy-makers at the action research continuum is essential for effective follow up, scaling up and sustainability of such environmentally sound practices.     

Climate adaptation imperatives: untapped global maize yield opportunities

Climate change represents an unavoidable and growing challenge to food security, imposing new adaptation imperatives on all farmers. Maize is arguably the world's most productive grain crop, as measured by grain yield. However, maize yields vary dramatically due to many factors, including soils, climate, pests, disease, agronomic practices, and seed quality. The difference between observed yields and those achievable by optimized crop production methods is called the yield gap. In this work we quantified the current yield gap for 44 countries through the use of a large private-sector data set recently made available to the crop modelling community. The yield gap was quantified for three groups of countries, categorized by level of intensification. Observed yield gaps for high, medium, and low levels of intensification are 23%, 46%, and 68%, respectively. If all maize production countries were able to shrink their yield gap to 16.5% (as in the USA) an additional 335?million metric tons (MMT) of maize grain would be produced. This represents a 45% increase over the 741?MMT produced by these countries in 2010. These data demonstrate that a major untapped maize yield opportunity exists, especially in those countries where intensification has not kept pace with the rest of the world.     

Understanding the adoption of climate change adaptation strategies among smallholder farmers: Evidence from land reform beneficiaries in South Africa

Climatic change has a negative impact on people’s livelihoods, agriculture, freshwater supply and other natural resources that are important for human survival. Therefore, understanding how rural smallholder farmers perceive climate change, climate variability, and factors that influence their choices would facilitate a better understanding of how these farmers adapt to the negative impacts of climate change. A Zero-inflated double hurdle model was employed to estimate the factors influencing farmers’ adoption of adaptation strategies and intensity of adoption at the household level in South Africa. Different socioeconomic factors such as gender, age, and experience in crop farming, institutional factors like access to extension services, and access to climate change information significantly influenced the adoption of climate change adaptation strategies among beneficiaries of land reform in South Africa. Concerning intensity of adoption, age, educational level, farming experience, on-farm training, off-farm income, access to information through ICT and locational variables are the significant determinants of intensity of adaptation strategies. Thus, education attainment, non-farm employment, farming experience are significant incentives to enhance smallholder farmers' adaptive capacity through the adoption of many adaptation approaches. This study therefore concluded that farm-level policy efforts that aim to improve rural development should focus on farmers’ education, on-farm demonstration and non-farm employment opportunities that seek to engage the farmers, particularly during the off-cropping season. The income from non-farm employment can be plough-back into farm operations such as the adoption of soil and water conservation, use of improved planting varieties, insurance, among others to mitigate climate variability and subsequently increase productivity. Policies and investment strategies of the government should be geared towards supporting education, providing on-farm demonstration trainings, and disseminating information about climate change adaptation strategies, particularly for smallholder farmers in the country. Thus, the government, stakeholders, and donor agencies must provide capacity-building innovations around the agricultural extension system and education on climate change using information and communication technologies.     

Climate change impacts on rain-fed and irrigated rice yield in Malawi

There is extensive scientific evidence on climate impacts and adaptation in rice (Oryza sativa L.), but the majority relates to production in South Asia and China. Only a handful of studies have been conducted in Sub-Saharan Africa and none in Malawi. In this paper, the climate impacts on rain-fed and irrigated rice yield have been assessed by combining the downscaled outputs from an ensemble of general circulation models (GCM) (HADCM3, INCM3 and IPCM4) with data from the LARS-WG weather generator to drive the CERES-Rice crop model. This was calibrated and validated using 10 years (2001–2010) field data from three rice schemes to simulate the baseline (1961–1990) yield (t?ha^?1) and then model future yield changes for selected (B1 and A2) emissions’ scenarios for the 2050s. Although relatively small increases in average yield were projected (+8% and +5% for rain-fed and irrigated rice, respectively), there was large uncertainty (?10% to +20% yield change) when considering different GCMs and emission scenario. Farmer responses to cope with the projected impacts include both autonomous and planned adaptation strategies, such as modifying planting dates to maximize crop growth calendars and available soil moisture, increased use of on-farm water conservation measures and land levelling to improve water efficiency in rice schemes dependent on surface irrigation.     

Examining multi-functionality for crop yield and ecosystem services in five systems of agroecological intensification

Agroecological intensification (AEI) integrates ecological principles and biodiversity management into farming systems with the aims of increasing farm productivity, reducing dependency on external inputs, and sustaining or enhancing ecosystem services. This review develops an analytic framework to characterize the fulfilment of these objectives by documenting the co-occurrence of positive, neutral, and negative outcomes for crop yield and nine regulating ecosystem services. We provide an illustrative examination of the framework, evaluating evidence for yield and ecosystem service outcomes across five AEI systems: conservation agriculture, holistic grazing management, organic agriculture, precision agriculture, and system of rice intensification (SRI). We reviewed 104 studies containing 245 individual comparisons between AEI and contrasting farming systems. In three of the five AEI systems, conservation agriculture, precision agriculture, and SRI, more than half of reviewed comparisons reported ‘win-win’ outcomes, enhancement of both yield and ecosystem services, or ‘win-neutral’ outcomes relative to contrasting farming systems. The review presents substantial evidence that the five AEI systems can contribute to multi-functional agriculture by increasing ecosystem service provision, or reducing negative externalities associated with agriculture, while maintaining or increasing yields. A framework such as the one presented here can help guide decision-makers considering how best to implement multi-functional agriculture so that both crop yield and ecosystem service delivery can be maintained or increased.     

全球变化背景下气候变暖对中国农业生产的影响

全球变化背景下,气候变暖势必对我国农业生产要素、生产环境、农业生产活动及粮食安全产生重大影响。文章采用文献综述与比较研究的方法,系统分析气候变化对我国光资源、温度、水环境和土壤环境等农业生产要素的影响特征及变化趋势,探讨气候变化对我国作物种植区域和种植制度、农作物病虫害、农业生产能力、农业经济与管理等农业生产活动以及农田生态系统过程、农业生态环境(水环境、土壤环境、耕作环境)的实际影响。在此基础上,明确了我国农业在应对气候变化过程中所面临的主要问题:极端气候事件发生频率加大,自然灾害、气象灾害的风险提高,农业生产的波动性增强;农业病虫害的为害时间延长、危害程度加剧、为害范围增大;农业生态环境日趋恶化,农田土壤的干旱化、盐渍化程度加剧,农业生产能力下降;应对气候变化的农业发展策略及其关键技术亟需解决。     

The political ecology of rice intensification in south India: Putting SRI in its places

The system of rice intensification (SRI) has been promoted across Asia as a means to improve rice yields while decreasing water use and external inputs. It is argued to be a generalisable means by which to revalidate smallholder livelihoods and improve food security across the region. Current debates about SRI, however, remain predominantly technical in scope, focusing on field‐level outcomes. To more adequately understand the potential of SRI for smallholder farmers, we argue that it is necessary to situate SRI within a political ecology framework that addresses how the adoption and practice of SRI is shaped by uneven access to key assets including labour, water, and extension networks. Fieldwork conducted in Mahabubnagar district in Telangana, south India—where SRI had been widely disadopted despite the achievement of higher yields—is used to illustrate why agronomic analysis must engage directly with the complex social contexts in which farmers operate.     

Climate precarity in rural livelihoods: Agrarian transformations and smallholder vulnerability in Vietnam

In recent decades, agrarian transformations in Southeast Asia have resulted in significant environmental and social change, yet insufficient attention has focused on the particular pathways by which these changes have increased vulnerability to climate change. In particular, climate precarity, a situation in which class, social, labour and/or gender inequities amplify negative impacts from climate change, has been on the rise for many smallholders. Using case studies in Vietnam of changes to swidden agriculture in upland areas and the loss of deepwater rice systems in the Mekong Delta lowlands, the paper examines social differentiation and ecological outcomes of these processes and how they have increased climate precarity, particularly for poor households and women. Based on longitudinal fieldwork in affected regions, we identify key changes contributing to climate precarity as farming systems intensify. In particular, loss of flexibility in farmer decision-making, loss of voluntary engagement with markets, and declining access to social capital and entitlements have increased risks for households and reduced adaptation options. Suggestions are made to more directly address these elements in future agricultural and climate policies, rather than current approaches to climate adaptation that often promote even more intensification of agriculture, which runs the risk of exacerbating precarity.     

Rice productivity in Bangladesh: What are the benefits of irrigation?

Green Revolution technologies transformed Bangladesh’s agricultural system through the introduction of high-yielding rice and wheat varieties, chemical fertilizers and pesticides, and the expansion of tubewell-irrigated area, enabling crop production during the dry season. However, serious challenges continue to plague the agriculture sector, including scarcity of land due to high population density, unbalanced use of fertilizers and pesticides, and great variation in water supply across seasons – from drought to stagnant flood conditions. Further expansion of irrigated area – including through the continued development and improvement of surface water systems – is being eyed by Bangladesh’s Ministry of Agriculture to address many of the remaining challenges facing the country. However, such expansion is not without risks or consequences, and a careful analysis of who benefits from irrigation, and how, must guide development priorities.We examine plot-level data for rice production during Bangladesh’s three rice seasons – aus, boro, and aman – across a nationally-representative household survey in Bangladesh. While rainfall is the most important determinant of rice yield during aus and chemical inputs are most important during aman, access to irrigation has the greatest influence on boro rice yield during the dry season, particularly for the coastal south. The government of Bangladesh is planning massive investments in the southern region for the improved provision of surface water irrigation. The expected decline in groundwater, coupled with our econometric findings, suggests that expanding boro production in the south may not be a good strategy to promote, for the region. Whether brackish shrimp aquaculture can provide an equitable and sustainable livelihood alternative should continue to be a focus of research.     

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.     

Gender and conservation agriculture in sub-Saharan Africa: a systematic review

Conservation agriculture (CA) involves the practice of concurrent minimum tillage, permanent soil cover using crop residue, and crop rotation. Evidence indicates that CA increases agricultural productivity, reduces farming labour requirements, and improves soil quality. While CA is practised in several African contexts, little is known about its interaction with gender. This review synthesized knowledge on the interplay of gender and CA in sub-Saharan Africa. The review highlighted the relative neglect of gender issues in research on CA in SSA. Existing research was limited both in quantity and to a few countries in the region. There was also little critical focus on gender as a social phenomenon: a few of the studies conceptualized gender in terms of the socially constructed roles of men and women while the majority framed it in terms of the sexual categories of male and female. Compared to men, and due largely to gendered barriers, including lack of access to land; machinery; inputs; extension services; and credit facilities, women farmers adopted CA less and dis-adopted it more. CA increased women’s incomes, labour involvement, household food security, as well as risks for land and crop dispossession by men when farming becomes lucrative. It also increased workloads, employment opportunities and health risks for women. CA positively altered gender relations, boosting women’s participation in agricultural decision-making at the household level. Deliberately enlisting women as beneficiaries; working with men to advance their understanding of women’s needs in agriculture; and offering agricultural inputs directly to women are some strategies that enhanced women’s participation in CA. Gaps in current research on gender and CA include: critical focus on and understanding of gender as a social construct in relation to CA; the long-term impacts on CA for gender relations, incomes for men and women, and women’s empowerment; the sustainability of strategies for supporting gendered participation in CA; and the dynamics of gendered access to local farmland markets for CA.