Modeling the Impacts of Conservation Agriculture with a Drip Irrigation System on the Hydrology and Water Management in Sub-Saharan Africa

Tewodros Assefa,Manoj Jha,Manuel Reyes,Abeyou Worqlul

doi:10.3390/su10124763

Tewodros Assefa, Manoj Jha + Show 2 more

Open Access

https://doi.org/10.3390/su10124763

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Journal: Sustainability	Publication Date: Dec 13, 2018
Citations: 23	License type: CC BY 4.0

Affiliation: Bahir Dar University, Kansas State University

Abstract

The agricultural system in Sub-Saharan Africa (SSA) is dominated by traditional farming practices with poor soil and water management, which contributes to soil degradation and low crop productivity. This study integrated field experiments and a field-scale biophysical model (Agricultural Policy Environmental Extender, APEX) to investigate the impacts of conservation agriculture (CA) with a drip irrigation system on the hydrology and water management as compared to the conventional tillage (CT) practice. Field data were collected from four study sites; Dangishita and Robit (Ethiopia), Yemu (Ghana), and Mkindo (Tanzania) to validate APEX for hydrology and crop yield simulation. Each study site consisted of 100 m2 plots divided equally between CA and CT practices and both had a drip irrigation setup. Cropping pattern, management practices, and irrigation scheduling were monitored for each experimental plot. Significant water savings (α = 0.05) were observed under CA practice; evapotranspiration and runoff were reduced by up to 49% and 62%, respectively, whereas percolation increased up to three-fold. Consequently, irrigation water need was reduced in CA plots by about 14–35% for various crops. CA coupled with drip irrigation was found to be an efficient water saving technology and has substantial potential to sustain and intensify crop production in the region.

Highlights

Agricultural production continues to face several challenges in Sub-Saharan Africa (SSA) leading to an insufficient food supply
The impacts of conservation agriculture (CA) on agricultural water management was analyzed through the integration of a field experiment and a biophysical model, Agricultural Policy Environmental Extender (APEX), at four study sites (Dangishita, Robit, Yemu, and Mkindo) in SSA
Once the APEX model was validated for hydrology and crop yield, the impacts of CA practices on water management was evaluated and compared with conventional tillage (CT) practice

Summary

Introduction

Agricultural production continues to face several challenges in Sub-Saharan Africa (SSA) leading to an insufficient food supply. Insufficient food supply leads to malnutrition, which accounts for more than one-third of all children’s death in the region [2] Another challenge is the rainfall-dependent farming system, which makes it susceptible to climate variability such as drought [3]. The expansion of traditional farming practices aiming to increase in food supply resulted in environmental deterioration due to conventional tillage practices [4,5] These challenges call for a sustainable growth in food production system that may come from (1) growing high value and nutritious food types, such as fruits and vegetables; (2) using efficient water use strategies (irrigation technologies) that can maximize production and support multiple cropping seasons; (3) enabling dry season cropping (climate resilient system) through water storage; and (4) disseminating best management practices through field demonstrations and other educational and outreach activities. The focus should be to empower smallholder farmers, which constitutes the majority of farms (80%) in SSA [6]

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