Critical slope length for soil loss mitigation in maize-bean cropping systems in SW Kenya

Soil erosion and land fragmentation threaten agricultural production of sub-Saharan African highlands. At our study site in Western Kenya, farm size is mostly < 2 ha, laid out in narrow strips in slope direction and ploughed downhill. Soil conservation measures like hedgerows and green manures can r...

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Autores principales: Koomson, E., Muoni, T., Marohn, C., Nziguheba, G., Öborn, Ingrid, Cadisch, Georg
Formato: Journal Article
Lenguaje:Inglés
Publicado: Elsevier 2020
Materias:
Acceso en línea:https://hdl.handle.net/10568/109380
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author Koomson, E.
Muoni, T.
Marohn, C.
Nziguheba, G.
Öborn, Ingrid
Cadisch, Georg
author_browse Cadisch, Georg
Koomson, E.
Marohn, C.
Muoni, T.
Nziguheba, G.
Öborn, Ingrid
author_facet Koomson, E.
Muoni, T.
Marohn, C.
Nziguheba, G.
Öborn, Ingrid
Cadisch, Georg
author_sort Koomson, E.
collection Repository of Agricultural Research Outputs (CGSpace)
description Soil erosion and land fragmentation threaten agricultural production of sub-Saharan African highlands. At our study site in Western Kenya, farm size is mostly < 2 ha, laid out in narrow strips in slope direction and ploughed downhill. Soil conservation measures like hedgerows and green manures can reduce effective slope length for erosion, but compete with crops for space and labour. Knowledge of critical slope length can minimise interventions and trade–offs. Hence, a maize–bean intercrop (MzBn) slope length trial on 20, 60 and 84 m long plots, replicated twice on three farms was carried out in Rongo, Migori County, during one rainy season. Soil loss from 84 m slope length (SL) plots was 250 % higher than from 60 m and 710% higher than from 20 m plots, while soil loss from 20 and 60 m plots did not differ (p < 0.05). Conversely, runoff was lower on the 84 m than on the 60 m (p < 0.05) or the 20 m SL (p < 0.05). Across all three farms slope gradient and length had highest explanatory power to predict soil loss. At individual farm level, under similar slope and soil texture, slope length and profile curvature were most influential. Regarding results of the slope length experiments, food crop plot lengths < 50 m appear essential considering soil loss, sediment load, and soil loss to yield ratio under the given rainfall, soil and slope (10–14%) conditions. Our results call for designing integrating slope length options and cropping systems for effective soil conservation. We recommend planting Mucuna and Calliandra–hedgerows as buffer strips below the critical slope length, and legume cash crops and maize uphill. Such approaches are critical against the backdrop of land fragmentation and labour limitation to sustainably maximise food production from the available land area in the region.
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spelling CGSpace1093802024-05-01T08:16:00Z Critical slope length for soil loss mitigation in maize-bean cropping systems in SW Kenya Koomson, E. Muoni, T. Marohn, C. Nziguheba, G. Öborn, Ingrid Cadisch, Georg maize beans intercropping cropping systems erosion legumes acrisols soil loss slope orientation exposition soil conservation Soil erosion and land fragmentation threaten agricultural production of sub-Saharan African highlands. At our study site in Western Kenya, farm size is mostly < 2 ha, laid out in narrow strips in slope direction and ploughed downhill. Soil conservation measures like hedgerows and green manures can reduce effective slope length for erosion, but compete with crops for space and labour. Knowledge of critical slope length can minimise interventions and trade–offs. Hence, a maize–bean intercrop (MzBn) slope length trial on 20, 60 and 84 m long plots, replicated twice on three farms was carried out in Rongo, Migori County, during one rainy season. Soil loss from 84 m slope length (SL) plots was 250 % higher than from 60 m and 710% higher than from 20 m plots, while soil loss from 20 and 60 m plots did not differ (p < 0.05). Conversely, runoff was lower on the 84 m than on the 60 m (p < 0.05) or the 20 m SL (p < 0.05). Across all three farms slope gradient and length had highest explanatory power to predict soil loss. At individual farm level, under similar slope and soil texture, slope length and profile curvature were most influential. Regarding results of the slope length experiments, food crop plot lengths < 50 m appear essential considering soil loss, sediment load, and soil loss to yield ratio under the given rainfall, soil and slope (10–14%) conditions. Our results call for designing integrating slope length options and cropping systems for effective soil conservation. We recommend planting Mucuna and Calliandra–hedgerows as buffer strips below the critical slope length, and legume cash crops and maize uphill. Such approaches are critical against the backdrop of land fragmentation and labour limitation to sustainably maximise food production from the available land area in the region. 2020-09 2020-09-09T09:05:22Z 2020-09-09T09:05:22Z Journal Article https://hdl.handle.net/10568/109380 en Limited Access Elsevier Koomson, E., Muoni, T., Marohn, C., Nziguheba, G., Öborn, I. & Cadisch, G. (2020). Critical slope length for soil loss mitigation in maize-bean cropping systems in SW Kenya. Geoderma Regional, 22: e00311, 1-9.
spellingShingle maize
beans
intercropping
cropping systems
erosion
legumes
acrisols
soil loss
slope orientation
exposition
soil conservation
Koomson, E.
Muoni, T.
Marohn, C.
Nziguheba, G.
Öborn, Ingrid
Cadisch, Georg
Critical slope length for soil loss mitigation in maize-bean cropping systems in SW Kenya
title Critical slope length for soil loss mitigation in maize-bean cropping systems in SW Kenya
title_full Critical slope length for soil loss mitigation in maize-bean cropping systems in SW Kenya
title_fullStr Critical slope length for soil loss mitigation in maize-bean cropping systems in SW Kenya
title_full_unstemmed Critical slope length for soil loss mitigation in maize-bean cropping systems in SW Kenya
title_short Critical slope length for soil loss mitigation in maize-bean cropping systems in SW Kenya
title_sort critical slope length for soil loss mitigation in maize bean cropping systems in sw kenya
topic maize
beans
intercropping
cropping systems
erosion
legumes
acrisols
soil loss
slope orientation
exposition
soil conservation
url https://hdl.handle.net/10568/109380
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