Integrating legume-based systems into wheat monoculture: Agronomic and soil fertility impacts in the southeastern highlands of Ethiopia

Wheat production in Ethiopia’s Bale highlands is central to national food security but is increasingly constrained by interannual climate variability, soil fertility decline, and competing demands for crop residues in mixed crop–livestock systems. To evaluate sustainable intensification pathways, we...

Full description

Bibliographic Details
Main Authors: Mesfin, Tewodros, Tibebe, Degefie, Abera, Wuletawu, Liben, Feyera, Mkuhlani, Siyabusa, Kouadio, Amani Louis
Format: Informe técnico
Language:Inglés
Published: Bioversity International and International Center for Tropical Agriculture 2025
Subjects:
Online Access:https://hdl.handle.net/10568/179596
_version_ 1855517742602387456
author Mesfin, Tewodros
Tibebe, Degefie
Abera, Wuletawu
Liben, Feyera
Mkuhlani, Siyabusa
Kouadio, Amani Louis
author_browse Abera, Wuletawu
Kouadio, Amani Louis
Liben, Feyera
Mesfin, Tewodros
Mkuhlani, Siyabusa
Tibebe, Degefie
author_facet Mesfin, Tewodros
Tibebe, Degefie
Abera, Wuletawu
Liben, Feyera
Mkuhlani, Siyabusa
Kouadio, Amani Louis
author_sort Mesfin, Tewodros
collection Repository of Agricultural Research Outputs (CGSpace)
description Wheat production in Ethiopia’s Bale highlands is central to national food security but is increasingly constrained by interannual climate variability, soil fertility decline, and competing demands for crop residues in mixed crop–livestock systems. To evaluate sustainable intensification pathways, we applied APSIM Classic (v7.10) within the AgWise framework to simulate long-term (1994–2024) performance of wheat monoculture and legume-integrated alternatives across a 10 × 10 km grid in Bale Zone, southeastern Oromia, Ethiopia, using gridded rainfall (CHIRPS), temperature (ERA5), solar radiation (NASA POWER), and 10-km soil profile data. Three wheat-based systems were assessed: continuous wheat, a wheat–faba bean rotation, and a field pea–wheat double-cropping sequence, with legumes simulated under 0 and 25 kg N ha⁻¹ starter N while wheat management was held constant (80 kg N ha⁻¹ split and 15 kg P ha⁻¹ per crop). System performance was quantified using annual system grain yield, interannual variability (CV), downside risk (years with yield <300 kg ha⁻¹), and soil indicators (organic carbon and profile NO₃–N). Legume integration generated strong spatially structured yield responses: the faba bean–wheat rotation supported by starter N produced the greatest yield potential and the largest site-to-site heterogeneity, including extreme high-yield outliers, whereas unfertilized double cropping frequently incurred a yield penalty. Nitrogen supply to the legume phase was pivotal for risk outcomes: unfertilized double cropping showed the highest yield instability and downside risk, while starter N reduced variability and shifted downside risk toward levels comparable to continuous wheat. Across systems, simulated soil organic carbon was higher under legume-based diversification than under continuous wheat, while elevated and slowly increasing profile NO₃–N was largely confined to the fertilized faba bean–wheat rotation. These results support spatially targeted promotion of legume–wheat systems, emphasizing modest starter N to legumes to maximize productivity while limiting downside risk under highland conditions.
format Informe técnico
id CGSpace179596
institution CGIAR Consortium
language Inglés
publishDate 2025
publishDateRange 2025
publishDateSort 2025
publisher Bioversity International and International Center for Tropical Agriculture
publisherStr Bioversity International and International Center for Tropical Agriculture
record_format dspace
spelling CGSpace1795962026-01-10T02:03:03Z Integrating legume-based systems into wheat monoculture: Agronomic and soil fertility impacts in the southeastern highlands of Ethiopia Mesfin, Tewodros Tibebe, Degefie Abera, Wuletawu Liben, Feyera Mkuhlani, Siyabusa Kouadio, Amani Louis legumes soil organic carbon mixed cropping wheat crop rotation double cropping spatial variations Wheat production in Ethiopia’s Bale highlands is central to national food security but is increasingly constrained by interannual climate variability, soil fertility decline, and competing demands for crop residues in mixed crop–livestock systems. To evaluate sustainable intensification pathways, we applied APSIM Classic (v7.10) within the AgWise framework to simulate long-term (1994–2024) performance of wheat monoculture and legume-integrated alternatives across a 10 × 10 km grid in Bale Zone, southeastern Oromia, Ethiopia, using gridded rainfall (CHIRPS), temperature (ERA5), solar radiation (NASA POWER), and 10-km soil profile data. Three wheat-based systems were assessed: continuous wheat, a wheat–faba bean rotation, and a field pea–wheat double-cropping sequence, with legumes simulated under 0 and 25 kg N ha⁻¹ starter N while wheat management was held constant (80 kg N ha⁻¹ split and 15 kg P ha⁻¹ per crop). System performance was quantified using annual system grain yield, interannual variability (CV), downside risk (years with yield <300 kg ha⁻¹), and soil indicators (organic carbon and profile NO₃–N). Legume integration generated strong spatially structured yield responses: the faba bean–wheat rotation supported by starter N produced the greatest yield potential and the largest site-to-site heterogeneity, including extreme high-yield outliers, whereas unfertilized double cropping frequently incurred a yield penalty. Nitrogen supply to the legume phase was pivotal for risk outcomes: unfertilized double cropping showed the highest yield instability and downside risk, while starter N reduced variability and shifted downside risk toward levels comparable to continuous wheat. Across systems, simulated soil organic carbon was higher under legume-based diversification than under continuous wheat, while elevated and slowly increasing profile NO₃–N was largely confined to the fertilized faba bean–wheat rotation. These results support spatially targeted promotion of legume–wheat systems, emphasizing modest starter N to legumes to maximize productivity while limiting downside risk under highland conditions. 2025-12 2026-01-09T13:09:05Z 2026-01-09T13:09:05Z Report https://hdl.handle.net/10568/179596 en Open Access application/pdf Bioversity International and International Center for Tropical Agriculture Abebe, T.M.; Degefie, D.T.; Abera, W.; Liben, F.M.; Mkuhlani, S. (2025) Integrating legume-based systems into wheat monoculture: Agronomic and soil fertility impacts in the southeastern highlands of Ethiopia. CGIAR Sustainable Farming Science Program. 28 p.
spellingShingle legumes
soil organic carbon
mixed cropping
wheat
crop rotation
double cropping
spatial variations
Mesfin, Tewodros
Tibebe, Degefie
Abera, Wuletawu
Liben, Feyera
Mkuhlani, Siyabusa
Kouadio, Amani Louis
Integrating legume-based systems into wheat monoculture: Agronomic and soil fertility impacts in the southeastern highlands of Ethiopia
title Integrating legume-based systems into wheat monoculture: Agronomic and soil fertility impacts in the southeastern highlands of Ethiopia
title_full Integrating legume-based systems into wheat monoculture: Agronomic and soil fertility impacts in the southeastern highlands of Ethiopia
title_fullStr Integrating legume-based systems into wheat monoculture: Agronomic and soil fertility impacts in the southeastern highlands of Ethiopia
title_full_unstemmed Integrating legume-based systems into wheat monoculture: Agronomic and soil fertility impacts in the southeastern highlands of Ethiopia
title_short Integrating legume-based systems into wheat monoculture: Agronomic and soil fertility impacts in the southeastern highlands of Ethiopia
title_sort integrating legume based systems into wheat monoculture agronomic and soil fertility impacts in the southeastern highlands of ethiopia
topic legumes
soil organic carbon
mixed cropping
wheat
crop rotation
double cropping
spatial variations
url https://hdl.handle.net/10568/179596
work_keys_str_mv AT mesfintewodros integratinglegumebasedsystemsintowheatmonocultureagronomicandsoilfertilityimpactsinthesoutheasternhighlandsofethiopia
AT tibebedegefie integratinglegumebasedsystemsintowheatmonocultureagronomicandsoilfertilityimpactsinthesoutheasternhighlandsofethiopia
AT aberawuletawu integratinglegumebasedsystemsintowheatmonocultureagronomicandsoilfertilityimpactsinthesoutheasternhighlandsofethiopia
AT libenfeyera integratinglegumebasedsystemsintowheatmonocultureagronomicandsoilfertilityimpactsinthesoutheasternhighlandsofethiopia
AT mkuhlanisiyabusa integratinglegumebasedsystemsintowheatmonocultureagronomicandsoilfertilityimpactsinthesoutheasternhighlandsofethiopia
AT kouadioamanilouis integratinglegumebasedsystemsintowheatmonocultureagronomicandsoilfertilityimpactsinthesoutheasternhighlandsofethiopia