Elsevier

Ecological Economics

Volume 93, September 2013, Pages 85-93
Ecological Economics

Surveys
Cropping system diversification, conservation tillage and modern seed adoption in Ethiopia: Impacts on household income, agrochemical use and demand for labor

https://doi.org/10.1016/j.ecolecon.2013.05.002Get rights and content

Highlights

  • Multiple technology choice and impacts modeled using multinomial endogenous switching regression

  • The highest income is achieved when technologies are adopted in combination rather than in isolation.

  • N fertilizer use is lower in the package that contains bio-diversification and conservation tillage.

  • Pesticide application and labor demand increase when conservation tillage adopted.

  • Adoption of packages increases women's workload.

Abstract

The type and combination of sustainable agricultural practices (SAPs) adopted have a significant effect on agricultural productivity and food security. This study develops a multinomial endogenous switching regression model of farmers' choice of combination of SAPs and impacts on maize income and agrochemicals and family labor use in rural Ethiopia. Four primary results were found. First, adoption of SAPs increases maize income and the highest payoff is achieved when SAPs are adopted in combination rather than in isolation. Second, nitrogen fertilizer use is lower in the package that contains system diversification and conservation tillage. Third, conservation tillage increased pesticide application and labor demand, perhaps to compensate for reduced tillage. However, when it is used jointly with system diversification, it does not have a significant impact on pesticide and labor use. Fourth, in most cases adoption of a package of SAPs increases women workload, suggesting that agricultural intensification technology interventions may not be gender neutral. This implies that policy makers and other stakeholders promoting a combination of technologies can enhance household food security through increasing income and reducing production costs, but need to be aware of the potential gender related outcomes.

Introduction

The major challenge facing sub-Saharan African (SSA) governments today is how to achieve food security and reduce poverty, while simultaneously mitigating degradation of essential ecosystem services. Most attention in the literature has been given to the low and stagnant returns from African agriculture (Bluffstone and Köhlin, 2011, Jhamtani, 2011, Pretty et al., 2011, World Bank, 2007). However, many ecosystem services, including nutrient cycling, nitrogen fixation, soil regeneration, and biological control of pests and weeds, are under threat in key African food production systems that are vital for sustainable food security. The causes of environmental degradation in SSA include declining fallow periods, inadequate investment in sustainable intensification, and a strong trajectory away from diversification in favor of mono-cropping in otherwise traditionally complex farming systems (Jhamtani, 2011, Lee, 2005, Pretty, 1999, Snapp et al., 2010, Woodfine, 2009). These trends have contributed to low agricultural productivity and food insecurity in SSA and will continue to do so at an accelerating rate under anticipated climate change.

Unfortunately, there is a risk of a trade-off between attempts to increase the productivity in African agriculture through “modernization packages,” which combine improved seed varieties with agrochemicals, and the resulting stress that these inputs place on ecosystem services. The loss of ecosystem services can in turn require greater use of agrochemicals (such as chemical fertilizers and pesticides) and can increase the demand for on-farm labor. For example, increased use of external inputs is needed to regulate pests and diseases under increasingly simplified mono-cropping systems. Weed and pest populations previously controlled by ecosystem services now require the use of pesticides (Fuglie, 1999, Knowler and Bradshaw, 2007) and/or more labor is needed to control them. In addition, if agrochemicals are not properly used, they can cause significant harm to the environment and human health.

In this context, Sustainable Agricultural Practices (SAPs)1 are strategies that can increase productivity in a sustainable way by addressing the degradation of ecosystem services and increasing the ability of smallholder farmers to adapt to climate variability and change (Antle and Diagana, 2003, Lee, 2005, Pretty et al., 2011, Woodfine, 2009).

This paper will analyze the application of various combinations of three SAPs. The first one is cropping system diversification (maize–legume rotation). This system provides many ecosystem services, including N fixation and C sequestration; breaking the life cycle of pests; improving weed suppression; and smoothing out the impacts of price fluctuations (Altieri, 1999, Di Falco et al., 2010, Jhamtani, 2011, Liebman and Dyck, 1993, Snapp et al., 2010, Tilman et al., 2002, Woodfine, 2009). This can save farmers the cost of fertilizer and pesticides. Minimizing the use of these inputs also contributes to the mitigation of climate change. System diversification enables farmers to grow products that can be harvested at different times and places and that have different weather or environmental stress-response characteristics. These varied outputs and degrees of resilience are a hedge against the risk of drought, extreme or unseasonal temperatures, rainfall variations and price fluctuations, all of which affect the productivity and income of smallholder systems.

The second SAP is adoption of conservation tillage. This can lead to substantial ecosystem service benefits by reducing soil erosion and nutrient depletion and conserving soil moisture (Fuglie, 1999, Tilman et al., 2002, Woodfine, 2009).

The third SAP considered is the introduction of modern seeds (Lee, 2005). In our case, the improved maize varieties used are primarily intended to increase yields, mostly augmented with fertilizer and pesticides, thus addressing food security and income needs (Bellon and Taylor, 1993, Fernandez, 1996). Adoption of improved seeds is likely to be an important strategy in adaptation to future climate change.

In this paper, we analyze adoption of a combination of these SAPs and their impacts on income and agrochemical use. Specifically, the paper focuses on two objectives. First, we analyze the factors motivating the adoption of a combination of SAPs (i.e., cropping system diversification, conservation tillage and modern maize seed) in the maize–legume farming system of Ethiopia. Second, we examine the implications of adopting various combinations of these practices on selected outcome variables; more specifically, maize income,2 use of agrochemicals such as N fertilizer and pesticides (insecticides and herbicides), and demand for agricultural female and male labor. We control for selection bias using a multinomial endogenous switching treatment effects approach.

Despite the multiple benefits of SAPs and considerable efforts by national and international organizations to encourage farmers to invest in them, there is still a lack of evidence on farmers' incentives and conditioning factors that hinder or accelerate adoption of inter-related SAPs. An improved understanding of farmers' adoption behavior and the potential economic and agrochemical use implications associated with adoption of these practices is therefore important for sustainable intensification in the region.

This paper adds to existing literature on adoption analysis and impacts of technology in the following ways. First, we investigate (for the first time, to our knowledge) whether adoption of SAPs in combination will provide more economic benefits and better regulate agrochemical use than adopting them individually. This knowledge is relevant to the debate on whether farmers should adopt technologies piecemeal or in a package. It is also valuable for designing effective extension policies by identifying a combination of technologies that deliver the highest payoff. Most previous adoption studies (e.g., Gebremedhin and Scott, 2003, Kassie et al., 2010, Kassie et al., 2011) have focused on an analysis of a single SAP using single equation models (e.g., probit or logit). However, farmers are faced with technology alternatives that may be adopted simultaneously as complements, substitutes or supplements to deal with their overlapping constraints, such as weeds, pest and disease infestations, and low soil fertility and crop productivity (Dorfman, 1996, Khanna, 2001, Moyo and Veeman, 2004). Earlier studies also ignore the possibility of a path or state of dependence: the choice of technologies adopted more recently by farmers may be partly dependent on earlier technology choices (Khanna, 2001, Wu and Babcock, 1998). Adoption and impact analysis of technologies that ignoring these inter-relationships may underestimate or overestimate the influence of various factors on the adoption decision and on the impacts of adoption (Wu and Babcock, 1998). Modeling technology adoption and impact analysis in a multiple technology choice framework is therefore important to capture useful economic information contained in interdependent and simultaneous adoption decisions (Dorfman, 1996).

Our second contribution is the use of comprehensive household and plot-level survey data covering major maize growing regions in Ethiopia. This has allowed us to include several policy relevant variables (e.g., governance indicators, kinship, rainfall, and pest and disease shocks, and farmers' expectations of social safety nets or social insurance during crop failure) that determine SAP adoption and outcome variables. These variables for which we have data were not considered in previous studies. Third, we contribute to the scant empirical evidence on the impacts of SAP adoption on agrochemical and labor use.

The rest of the paper is organized as follows. Section 2 provides a brief description of the data. Section 3 presents a conceptual and econometric framework for a multinomial adoption selection model and estimation of average treatment effects. This is followed by a presentation of the empirical specifications of our estimation model. In Section 5, we discuss our estimation results. The final section concludes and draws key findings and policy implications.

Section snippets

The Data and Definitions of Variables

The dataset used for this study is based on a farm household survey conducted in Ethiopia during October–December 2010 by the Ethiopian Institute of Agricultural Research (EIAR) in collaboration with the International Maize and Wheat Improvement Center (CIMMYT). The sample consists of 900 farm households and about 1644 farming plots. A multistage sampling procedure was employed to select peasant associations (PAs)3 from each district and

Conceptual and Econometric Framework

In a multiple adoption setting, farmers' simultaneous adoption of cropping system diversification, conservation tillage, and an improved maize variety leads to eight possible SAP combination options that a farmer could choose. The actual choice is expected to be based on the farmer's expected profit from adoption given his/her constraints. We model farmers' choice of SAP packages (i.e., alternative combinations of system diversification, conservation tillage, and modern maize seed) and outcome

The Empirical Specification

The specification of our empirical model is based on a review of theoretical work and previous similar empirical adoption and impact studies (Bandiera and Rasul, 2006, D'Souza et al., 1993, Di Falco et al., 2010, Fuglie, 1999, Kasem and Thapa, 2011, Kassie et al., 2010, Kassie et al., 2011, Knowler and Bradshaw, 2007, Lee, 2005, Neill and Lee, 2001, Wollni et al., 2010). According to this literature, many factors affect adoption and thus affect our outcome variables. These factors include farm

Factors Explaining the Adoption of a SAP Package

The results from the multinomial logit model are presented in Table 4.8 The base category is non-adoption (R0V0T0), where results are compared.

The model fits the data reasonably well. The Wald test that all regression coefficients are jointly equal to zero is rejected [χ2(266) = 956.44; p = 0.000]. The results show that the estimated coefficients differ substantially across the alternative packages.

The spouse's

Concluding Remarks

Adoption of SAPs and the effects of adoption have received considerable attention from development economists. Prior research focuses on specific practices; less information is available on simultaneous adoption of multiple and interdependent SAPs and their impacts. In this paper, we evaluate the adoption of multiple SAPs and their impacts on maize income, agrochemicals, and labor input intensity in maize–legume farming systems of Ethiopia. A multinomial ESR is used to account for

Acknowledgments

This research was supported by the Australian Center for International Agricultural Research (ACIAR) and the Australian International Food Security Center (AIFSC) under the CIMMYT-led SIMLESA project for Sustainable Intensification of Maize-Legume Cropping Systems in Eastern and Southern Africa. Additional financial and logistic support for this study from EIAR (Ethiopian Institute of Agricultural Research) and Sida (Swedish International Development and Cooperation Agency) through the

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