Options for Sustainable Intensification of Maize Production in Ethiopia

Amit Srivastava,Thomas Gaiser,Arnim Kuhn,Babacar Faye,Cho Mboh,Frank Ewert,Engida Ermias

doi:10.3390/su11061707

Abstract

The agricultural intensification of farming systems in sub-Saharan Africa is a prerequisite to alleviate rural poverty and to improve livelihood. In this modelling exercise, we identified sustainable intensification scenarios for maize-based cropping systems in Ethiopia. We evaluated Conventional Intensification (CI) as continuous maize monocropping using higher Mineral Fertilizer (MF) rates with and without the incorporation of Crop Residues (CR) in the soil. We also evaluated the effect of groundnut in rotation with the maize-based cropping system with the current Farmer’s Practice + Rotation (FP + Rotation) and increased MF application rates (CI + Rotation) combined with CR incorporation. The results suggest that, under CI, there was a positive effect of MF and CR. The incorporation of only CR in the field increased the maize yield by 45.3% compared to the farmer’s yield under current MF rates. CR combined with higher MF (60 kg N ha−1 + 20 kg P ha−1) increased the yield by 134.6%. Incorporating CR and MF was also beneficial under rotation with groundnut. The maize yields increased up to 110.1% depending upon the scenarios tested. In the scenario where CR was not incorporated in the field, the maize yield declined by 21.9%. The Gross Economic Profit suggests that groundnut in rotation with maize is advantageous across Ethiopia in terms of the net return with a few exceptions.

Highlights

Sub-Saharan Africa (SSA) is the region at greatest food security risk because, by 2050, its population is likely to increase 2.5-fold and the demand for cereals will approximately be tripled [1]
The simulated average grain yield of both the maize varieties was comparable to the corresponding observations where the model overestimated the grain yield of variety BH660 by 4% and underestimated the grain yield of variety BH540 by −1.6% (Table 3), whereas plotting all the observation points of variety BH660 (n = 3) and BH540 (n = 5) with the corresponding simulated values resulted in high root mean square values (RMSE) (Figure 3)
The conventional intensification option explored in the current study shows the positive effect of mineral fertilizer application and the incorporation of the crop residue back in the field

Summary

Introduction

Sub-Saharan Africa (SSA) is the region at greatest food security risk because, by 2050, its population is likely to increase 2.5-fold and the demand for cereals will approximately be tripled [1]. The prevailing practice of low-input agriculture is providing little outputs and detrimental to soils [3] These issues, combined with continuous cereal-based cropping systems without sufficient nutrient inputs to the soil, have led to large-scale declines in soil fertility and persistently poor crop yields on smallholder farms [4]. Grain legumes fix atmospheric nitrogen gas (N2) and can contribute to the N economy of fields, provide other rotational benefits to subsequent crops, produce in situ high-quality organic residues with a high N concentration and a low C to N ratio, and thereby contribute to integrated soil fertility management [8]. Farmers seldom consider the long-term benefits, focusing instead on single years This leads to an underestimation of the services provided by legumes. The valuation of such services requires an assessment at the cropping-system scale [9]

Objectives

Methods

Results

Discussion

Conclusion