The Effects of Training, Innovation and New Technology on African Smallholder Farmers' Economic Outcomes and Food Security: A Systematic Review

摘要

Many poor people living in Africa depend on their small farms for survival. There has been a lot of interest in trying to reduce poverty in the region by supporting these farmers to produce more and make a profit from their farms. Such interventions include training farmers and introducing them to new farming techniques and products, such as new crop types or fertilisers. Although a substantial amount of money has been invested in these approaches by governments and international donors, the effects of these interventions on food security and economic outcomes are unclear. This review examines the effectiveness of training, innovation and new technology interventions on the economic outcomes and food security of smallholder farmers in Africa. Interest has grown in interventions to support smallholder farmers because such interventions have the potential to improve both household income and food security. This review confirms providing smallholders with new biological or chemical inputs, particularly orange‐fleshed sweet potato, can lead to improved income and nutrition status. More high‐quality studies are needed to assess other types of training, innovation, and new technology interventions. Research is also needed to assess whether such interventions have sustainable, long‐term effects and whether they may cause harm to farmers or their communities. Plain Language Summary BACKGROUND Many poor people living in Africa depend on their small farms for survival. There has been a lot of interest in trying to reduce poverty in the region by supporting these farmers to produce more and make a profit from their farms. This has included providing training programmes for farmers and introducing new products and farming techniques, such as fertilizers or new types of crops. Although a substantial amount of money has been invested in these approaches by governments and international donors, the effects of these interventions on food security and economic outcomes are unclear. We therefore set out to systematically review the available evidence. APPROACH We searched thoroughly in major academic databases related to agricultural development (e.g. CAB abstracts, EbscoHost), as well as in the grey literature for all relevant research about the effects of training or the introduction of new approaches on smallholder farmers in Africa. We took steps to ensure we only selected the research that was relevant to our question and where we had confidence in the results. We synthesised the results of included studies using meta–analysis, although some sub–groups of studies could not be combined due to heterogeneity of outcome measures and lack of consistent reporting of statistical information. FINDINGS Out of the many thousands of research studies available on farming in Africa, we identified 19 relevant studies. Our analysis does not provide a coherent picture of the effects of training, innovation and new technology interventions on smallholder farmers' livelihoods. The conducted meta–analyses are based on very limited samples of rigorous research. Keeping this limitation in mind, there seems to be some promise that agricultural input innovations, in particular orange–fleshed sweet potato (OFSP), might have positive effects on smallholders' levels of food security (g=0.71; 0.44, 0.98). There are also some positive indications that training interventions might have beneficial effects on farming households' income although these findings are not statistically significant (g=0.12; −0.04, 0.27; n=4). IMPLICATIONS Our systematic review presents training, innovation and new technology interventions as holding some potential to support African smallholder farmers' livelihoods. However, the true potential of these interventions is difficult to assess due to a lack of rigorous research evidence, and the prevailing heterogeneity in context and risk of bias in the limited sample of available research. Executive Summary BACKGROUND The majority of the rural poor in Africa depend on smallholder farming as a livelihood strategy. Yet smallholder farming systems are constrained by a lack of agricultural inputs and access to farming resources. Smallholder farming thus rarely exceeds levels of subsistence production. Interest in African smallholders has been growing in the last decade (World Bank, 2007). Improving smallholder farming systems has a direct nexus to agricultural development and poverty reduction. Smallholder farming interventions aim to improve both household income and food security among rural households. As a result they have been presented as a holistic and cost–effective approach to target rural development and poverty reduction. The introduction of innovation and new technologies and the provision of training represent two important interventions targeted at smallholder farmers in Africa. OBJECTIVES To systematically review evidence on the effects of training, innovation and new technology on African smallholder farmers' economic outcomes and food security. SEARCH STRATEGY An exhaustive search of the academic and grey literature covering the literature published between 1990–2014 yielded 18,470 citations derived from 39 sources. Reference lists from previous reviews and from included studies were also examined. A systematic map of evidence further informed the scope and specificity of search terms and sources. Search strings were developed in conjunction with information scientists and covered key terms related to smallholder farming, impact evaluation, Africa, and the interventions of interest. SELECTION CRITERIA This review includes impact evaluations that investigate the effects of training, innovation and new technology on the economic outcomes and food security of African smallholder farmers. To be eligible for inclusion in this review studies were required to: a) be conducted in Africa; b) feature smallholder farmers as the target population; c) evaluate a training programme and/or facilitation of innovation and new technology; d) measure the effects of these interventions on economic outcomes or food security; and e) use experimental or quasi–experimental methods. DATA COLLECTION & ANALYSIS Data were extracted from the included studies using a detailed coding tool. The risk of bias of the included studies was assessed using the risk of bias tool developed by the Cochrane Methods group (Higgins et al. 2011) and adapted for non–randomised studies (Sterne et al. 2013). To ensure the uniform application of these tools, we evaluated the reliability of reviewers' assessments through the calculation of an inter–reviewer Cohen's kappa score. Coding, screening and quality appraisal was done on EPPI–Reviewer (Version 4.3.6.0), which was further used to store data throughout the review process. We conducted a statistical meta–analysis of standardised mean differences for agricultural input innovations and training interventions. Due to heterogeneity and lack of statistical information the studies assessing the effects of agricultural practice innovation were synthesised narratively. RESULTS A total of 19 studies reported in 32 papers (comprising a total of 4,493 participants) met the inclusion criteria of the review. These studies assessed mainly the effects of innovation and new technology interventions (n=14). Agricultural input innovations, such as biofortified food crops present the most common form of innovation (n=12). Only five studies investigated the effects of training interventions. Of these, three training programmes assessed the effects of farmer field schools. The overall quality of the included studies was mixed and roughly split into two halves. The first half (11 studies) consisted of reliable evidence with nine low and two moderate risk of bias ratings. The second half consisted of eight studies and presented less reliable evidence as six studies were judged at serious risk of bias and two at critical risk of bias. Of the nine studies rated as low risk of bias, seven used randomised control trial designs (RCTs) and two evaluations applied rigorous quasi–experimental designs. We are unable to reach definitive findings regarding the effects of the reviewed smallholder farming interventions on farmers' economic outcomes and food security. The conducted meta–analyses are based on very small samples of evidence and are further compromised by large heterogeneity across studies' effect sizes and risk of bias. In this context we present the detailed results of our statistical syntheses: Synthesising the effect sizes of six agricultural input innovations, we identified an improvement in farmers' levels of food security as measured by nutritional indicators (g=0.71; 0.44, 0.98). Synthesising the effects of five OFSP interventions, we identify an improvement in farmers' levels of food security as measured by nutritional indicators (g=0.86; 0.59, 1.13). Synthesising the effects of three agricultural input innovations, we identify an improvement in farmers' income as modelled on the increased monetary value of their total harvest (g=0.26; 0.1, 0.41). Synthesising the effects of five training interventions, we fail to find an effect on farmers' income as modelled on the monetary value of their total harvest (g=0.12; −0.04, 0.27). We caution against using these pooled effect sizes as rigorous evidence of the positive effects of the reviewed interventions on smallholder farmers' livelihoods in Africa. Given the small sample and its risk of bias, the findings of our limited statistical analyses merely provide evidence that innovation and new technology, as well as training interventions hold potential to support smallholder farmers. As we did not identify evidence of harm caused by these programmes, the small amount of the available and synthesised evidence does lend some cautious support to the positive effects of these interventions. Within the reviewed interventions OFSP, as a Vitamin A rich staple food, presented the most promising intervention approach. OFSP programmes yielded positive effects on nutrition in four different contexts and programmes have successfully been taken to scale. AUTHORS' CONCLUSIONS The evidence identified by our systematic review does not allow for definite conclusions on the effects of training, innovation and new technology interventions on smallholder farmers' economic outcomes and food security in Africa. The limited synthesised evidence suggests agricultural input innovations might increase the nutritional status of farming households. They might also, albeit to a lesser degree, increase the monetary value of famers' harvest. Training programmes potentially might lead to increased household income as well; similarly through an increase of the monetary value of farmers' harvests. However, more rigorous research, that is theory–based impact evaluations of smallholder farming interventions, is required to explore these promising findings. In the context of renewed interest in smallholder farming as a key approach to rural development, this review provides cautious support to sustain this focus on smallholder farmers. The limited synthesised evidence points into the direction that efforts to support smallholder farmers have the potential to improve rural livelihoods. We made specific recommendations to policy–makers, researchers, and future review teams.