Scaling-Up Conservation Agriculture Production System with Drip Irrigation by Integrating MCE Technique and the APEX Model

Tewodros Assefa,Manoj Jha,Seifu Tilahun,Manuel Reyes,Abeyou W Worqlul

doi:10.3390/w11102007

Tewodros Assefa, Manoj Jha + Show 3 more

Open Access

https://doi.org/10.3390/w11102007

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Journal: Water	Publication Date: Sep 27, 2019
Citations: 5	License type: CC BY 4.0

Affiliation: Bahir Dar University, Kansas State University

Abstract

The conservation agriculture production system (CAPS) approach with drip irrigation has proven to have the potential to improve water management and food production in Ethiopia. A method of scaling-up crop yield under CAPS with drip irrigation is developed by integrating a biophysical model: APEX (agricultural policy environmental eXtender), and a Geographic Information System (GIS)-based multi-criteria evaluation (MCE) technique. Topography, land use, proximity to road networks, and population density were considered in identifying potentially irrigable land. Weather and soil texture data were used to delineate unique climate zones with similar soil properties for crop yield simulation using well-calibrated crop model parameters. Crops water demand for the cropping periods was used to determine groundwater potential for irrigation. The calibrated APEX crop model was then used to predict crop yield across the different climatic and soil zones. The MCE technique identified about 18.7 Mha of land (16.7% of the total landmass) as irrigable land in Ethiopia. Oromia has the highest irrigable land in the nation (35.4% of the irrigable land) when compared to other regional states. Groundwater could supply a significant amount of the irrigable land for dry season production under CAPS with drip irrigation for the various vegetables tested at the experimental sites with about 2.3 Mha, 3.5 Mha, 1.6 Mha, and 1.4 Mha of the irrigable land available to produce garlic, onion, cabbage, and tomato, respectively. When comparing regional states, Oromia had the highest groundwater potential (40.9% of total potential) followed by Amhara (20%) and Southern Nations, Nationalities, and Peoples (16%). CAPS with drip irrigation significantly increased groundwater potential for irrigation when compared to CTPS (conventional tillage production system) with traditional irrigation practice (i.e., 0.6 Mha under CTPS versus 2.2 Mha under CAPS on average). Similarly, CAPS with drip irrigation depicted significant improvement in crop productivity when compared to CTPS. APEX simulation of the average fresh vegetable yield on the irrigable land under CAPS with drip irrigation ranged from 1.8–2.8 t/ha, 1.4–2.2 t/ha, 5.5–15.7 t/ha, and 8.3–12.9 t/ha for garlic, onion, tomato, and cabbage, respectively. CAPS with drip irrigation technology could improve groundwater potential for irrigation up to five folds and intensify crop productivity by up to three to four folds across the nation.

Highlights

Crop production in Ethiopia is constrained with several challenges that cause low productivity and economic growth in the region
The results of scaling-up crop yield under conservation agriculture production system (CAPS) with drip irrigation technology to country-level were presented into three categories: (1) Assessment of potentially irrigable land in the country using the multi-criteria evaluation (MCE) technique, (2) simulation of potential crop production under CAPS with drip irrigation using a well-calibrated agricultural policy environmental eXtender (APEX) model, and (3) assessment of groundwater potential for dry season crop production
The various land use classes in the nation (Figure 3b) were reclassified into four suitability classes based on Assefa et al [2], Worqlul et al, [3], and Food and Agricultural Organization (FAO) [53]: Highly suitable, moderately suitable, marginally suitable class, and unsuitable class

Summary

Introduction

Crop production in Ethiopia is constrained with several challenges that cause low productivity and economic growth in the region. Soil degradation in the form of soil erosion and decline of soil fertility is the major constraint for crop production [1]. The alarming rise in population caused the exploitation of the rainforest and grasslands in the region to increase cultivated lands, which resulted in soil degradation and deterioration of the environment [2,3,4]. Crop production in the nation is mainly a rainfed system using traditional farming practices [2]. The expansion of cultivated land at the expense of forest, bushes, and grassland is not a feasible option to sustain crop production let alone increased productivity. With the current poor soil and water management practices, it contributes to lower production efficiency [3]

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Conclusion