Do the benefits of improved management practices to nutritional outcomes “dry up” in the presence of drought? Evidence from East Africa
Introduction
Nutrition persists as one of the most pressing issues for farmers in East Africa. Smallholder and rain-fed farms account for the majority of farmland in the region (Sheahan and Barrett, 2017) and the ever-present threat of crop failure creates high levels of uncertainty for both households and the governments that serve them. Drought, in particular, is an increasing concern. Drought years have been shown to have large negative effects on food availability, quantity, and quality, leading to costly coping mechanisms (Wineman et al., 2017, Carter and Lybbert, 2012, Janzen and Carter, 2019). While governments and non-governmental organizations seek to offset these effects, emergency assistance is often slow and expensive. Increasingly, policy and investments are made for the creation and promotion of management practices that can help shore up nutritional security.
In order to create evidence-based food and agricultural policy for East Africa, it is important to understand whether the beneficial relationship between best management practices and nutritional outcomes is primarily apparent in “good” (non-drought) years or in “bad” (drought) years. While strategies associated with improved nutritional outcomes in non-drought years are beneficial, they may do little to foster resilience or displace the need for emergency assistance during drought years. If, on the other hand, outcomes are improved primarily through a reduction in negative effects of drought on nutrition, then the creation and promotion of better management practices can be viewed as an investment in the resilience of smallholder farmers in regions where rain-fed agriculture is prominent.
We use household-level panel data from Tanzania and Mozambique to study the relationship between management practices and nutritional outcomes, with particular attention to how that relationship is mediated by drought. Specifically, this paper reports on three management practices that are common tenets of agricultural policies: use of improved seed varieties, use of chemical fertilizers, and on-farm production diversity. For each management practice, we present evidence on its association with two facets of household nutrition: dietary diversity and food security outcomes.
This paper contributes to the literature in three ways. First, we contribute to the literature documenting the potential benefits of management practices and the harmful nature of drought on nutritional outcomes. We find that, on average and as expected, improved management practices are associated with more diverse diets, higher probabilities of food security, and less severe food insecurity. The associations are particularly strong for use of improved maize seed varieties and production diversity. Next, we contribute an investigation of whether the positive relationship between management practices and nutritional outcomes is concentrated only in good years or is also present in drought years. We find that positive associations exist in both drought and non-drought years, which is encouraging. At the same time, the reduction in outcomes associated with drought is still larger than the increase in outcomes associated with management practices. As such, the allocation of resources between emergency assistance and promotion of improved management practices will continue to be an important policy decision for those seeking to improve resilience. On our way to this result, we also contribute to the literature on nutritional outcomes among farm households by documenting the imperfect overlap between dietary diversity and food security measures.
The paper proceeds as follows; first we provide an overview of the context and literature that frame our work. The following sections lay out the methodology and data used in our analysis of nutritional outcomes, management practices, and drought. Section 3 contains our primary analysis, demonstrating the association between management practices and nutritional outcomes in drought and non-drought years. We conclude with a discussion of the implications of these results for farm-household resilience and agricultural policy.
Nutritional failures in the early years of life can have long-term consequences on health and development (Alderman et al., 2006, Hoddinott and Kinsey, 2001). These consequences can stem from households pursuing strategies to deal with shocks to agricultural production and income that do not completely provide the nutrition necessary for growth and development. Shocks that affect entire communities, in particular, are more likely to have long-term consequences than idiosyncratic shocks that can be mediated by community-level informal insurance (Carter and Maluccio, 2003).
Drought is, perhaps, the prototypical community-level shock. Not only does drought directly affect households’ agricultural production, but the threat of drought may induce households to reduce current consumption in order to protect productive assets viewed as critical for longer term economic and food security (Carter and Lybbert, 2012, Janzen and Carter, 2019). More vulnerable households may also choose conservative management practices (Alderman and Paxson, 1994, Deaton, 1989) – increasing precautionary savings (Zimmerman and Carter, 2003, Lee and Sawada, 2010), or diversifying production into more drought-resistant staple crops (Barnett et al., 2008) – in order to ensure that they can obtain sufficient calories even in years characterized by drought.
With climate change predicted to increase the frequency and severity of drought events, particularly in Africa (Niang et al., 2014), protecting households’ economic and nutritional security is of increasing importance. Improved agricultural management practices are often central tenets of this effort and of agricultural policy in the region more broadly (Ariga et al., 2019, Sasson, 2012). Adoption of these practices can have both a level effect (increased average yields) and a stabilizing effect (reduced yield variation) on production (Rusinamhodzi et al., 2012, Fisher et al., 2015, Koussoubé and Nauges, 2017).
Three management practices, in particular, are relevant for the analysis conducted in this paper: use of improved seed varieties, use of chemical fertilizer, and production diversity. Jayne and Rashid (2013) report that in 2011, ten countries in Africa were spending over a billion dollars each – on the order of 30% of their public agricultural budget – on input subsidies.1 Public research dollars have similarly been poured into developing and promoting inputs with an eye to improving income and food security. In terms of improved seed use, we focus on maize, which is a primary staple crop both in the region and for the sample of households studied here.
Increased adoption of improved seed varieties – certified seed varieties produced using selective breeding to display desirable traits such as increased synchronization of pollination – in sub-Saharan Africa is one approach to improving livelihoods and managing vulnerability to drought (Shiferaw et al., 2014a, Kassie et al., 2015). Drought tolerant staple crops, maize among them, have been a focus of policy makers and non-governmental agencies for decades (CIMMYT, 2012, Fisher et al., 2015, Shiferaw et al., 2014b). The International Center for the Improvement of Maize and Wheat (CIMMYT) Drought Tolerant Maize for Africa (DTMA) program released 233 drought-tolerant maize varieties across thirteen countries between 2007–2015, with the explicit goal of raising incomes and strengthening food security (Abate et al., 2015). These investments have been estimated to generate billions of dollars of benefits by raising the level of and stabilizing maize yields (Kostandini et al., 2009, Kostandini et al., 2013). Less evidence exists on how these agricultural practices and outcomes map into nutritional outcomes.
Chemical fertilizers, as well, have often been the target of input subsidies, with varied evidence of success. Often, the costs of the programs seem to outweigh the benefits in the context of food prices and poverty rates, despite modest increases in yield (Jayne and Rashid, 2013, Jayne et al., 2018, Ricker-Gilbert, 2020). Mixed evidence exists as to fertilizer’s profitability for average smallholder farmers (Duflo et al., 2008, Koussoubé and Nauges, 2017) and benefits have been shown to be constrained by vulnerable farmers’ ability to access and use complementary inputs (Ricker-Gilbert and Jayne, 2017, Harou et al., 2017). Further, there is some evidence that yield response to fertilizer might be diminished by the more-acidic than average soil in sub-Saharan Africa (Burke et al., 2017). However, in a recent randomized controlled trial, a temporary input subsidy, which provided targeted discount vouchers for a bundle of improved maize and fertilizer to farmers believed to have high potential gains from the program, was found to have lasting effects of increased yields (Carter et al., 2021). The mixed evidence in support of the average agricultural and economic benefits of chemical fertilizer comes with longstanding acknowledgment that they may also increase yield variability (Just and Pope, 1979).
The final management practice we study is production diversity. Of the three, the largest literature assessing the relationship between a management practice and nutritional outcomes exists for production diversity. For the most part, dietary diversity is positively associated with on-farm production diversity. The evidence, however, is mixed (Rosenberg et al., 2018, Jones, 2017). In a meta-analysis of 45 studies based in 26 countries, Sibhatu and Qaim (2018b) found small but positive effects of production diversity on dietary diversity. There is also evidence that measurement and definitions can drive some of the relationships found between production diversity and nutrition. For example, production diversity is positively associated with dietary indicators but only when considering the number of species produced rather than the number of food groups (Sibhatu and Qaim, 2018a). In another study, increased production of non-staple crops drove increasing measures of dietary diversity (Gupta et al., 2020).
Section snippets
Methodology
In the analysis below, we focus on estimating the association between nutritional outcomes, drought, and management practices. We consider measures of both dietary diversity and food security as nutritional outcomes, drawing particular attention to their imperfect overlap. While we believe the evidence provided to be useful for understanding the relationships between management practices and nutritional outcomes, we refer to our results as associations rather than causal impacts. Though we use
Nutritional outcomes and drought
We begin our analysis by documenting the association between drought and nutritional outcomes. As discussed in Section 1.1, there is ample evidence that drought can be damaging to household well-being. Nor is drought infrequent. Table 2 noted that nearly half of the observations in the data come from households that recently experienced drought conditions during the growing season for maize. This statistic is made visible in Fig. 3, which displays households’ drought experience across the three
Policy implications and conclusions
Previous literature, including work published in this journal such as Amadu et al. (2020) and Shiferaw et al. (2014b), has demonstrated that certain management practices are associated with improved nutritional outcomes on average. Our analysis further bolsters the evidence supporting policies that promote agricultural inputs and education. We demonstrate that use of improved maize and a diverse portfolio of production are associated with improved nutritional outcomes. Given the different
CRediT authorship contribution statement
J.G. Malacarne: Conceptualization, Methodology, Software programming, Validation, Formal analysis, Investigation, Data curation, Writing, Visualization. L.A. Paul: Conceptualization, Methodology, Software programming, Validation, Formal analysis, Investigation, Data curation, Writing, Visualization.
Acknowledgments
This study was made possible through the generous support of the American people through the United States Agency for International Development Cooperative Agreement No. AID-OAA-L-12-00001 with the BASIS Feed the Future Innovation Lab. The contents are the responsibility of the authors and do not reflect the views of the US Government. The project’s activities in both countries were ruled Exempt under Category 2 by the IRB at the University of California, Davis. Project numbers: 905582-1
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