Araya Weldeslassie, Tesfay

Baudron, Frédéric

Cornelis, Wim

Deckers, Jozef

Govaerts, Bram

Lanckriet, Sil

Nyssen, Jan

Ghent University Academic Bibliography

Geophysical Research AbstractsVol. 16, EGU2014-86-1, 2014EGU General Assembly 2014© Author(s) 2013. CC Attribution 3.0 License.Eight years of Conservation Agriculture-based cropping systems researchin Eastern Africa to conserve soil and water and mitigate effects of climatechangeTesfay Araya (1), Jan Nyssen (2), Bram Govaerts (3), Sil Lanckriet (2), Frédéric Baudron (4), Jozef Deckers (5),and Wim Cornelis (6)(1) Mekelle University, Department of Crop and Horticultural Science, P. O. Box 231, Mekelle, Ethiopia(tesfayaraya@yahoo.com), (2) Ghent University, Department of Geography WE12, Gent, Belgium, (3) International Maizeand Wheat Improvement Centre (CIMMYT), A.P. 6-641, Mexico D.F. 06600, México, (4) International Maize and WheatImprovement Centre (CIMMYT), P.O. Box 5689, Addis Ababa, Ethiopia, (5) KU Leuven, Department of Earth andEnvironmental Sciences, Celestijnenlaan 200E, B-3001 Heverlee, Belgium, (6) Ghent University, Department of SoilManagement, Coupure Links 653, B-9000 Gent, BelgiumIn Ethiopia, repeated plowing, complete removal of crop residues at harvest, aftermath grazing of crop fields andoccurrence of repeated droughts have reduced the biomass return to the soil and aggravated cropland degradation.Conservation Agriculture (CA)-based resource conserving cropping systems may reduce runoff and soil erosion,and improve soil quality, thereby increasing crop productivity. Thus, a long-term tillage experiment has beencarried out (2005 to 2012) on a Vertisol to quantify - among others - changes in runoff and soil loss for twolocal tillage practices, modified to integrate CA principles in semi-arid northern Ethiopia. The experimental layoutwas a randomized complete block design with three replications on permanent plots of 5 m by 19 m. The tillagetreatments were (i) derdero+ (DER+) with a furrow and permanent raised bed planting system, ploughed onlyonce at planting by refreshing the furrow from 2005 to 2012 and 30% standing crop residue retention, (ii) terwah+(TER+) with furrows made at 1.5 m interval, plowed once at planting, 30% standing crop residue retention andfresh broad beds, and (iii) conventional tillage (CT) with a minimum of three plain tillage operations and completeremoval of crop residues. All the plowing and reshaping of the furrows was done using the local ard ploughmahresha and wheat, teff, barley and grass pea were grown. Glyphosate was sprayed starting from the third yearonwards (2007) at 2 l ha-1 before planting to control pre-emergent weeds in CA plots. Runoff and soil loss weremeasured daily. Soil water content was monitored every 6 days. Significantly different (p<0.05) runoff coefficientsaveraged over 8 years were 14, 20 and 27% for DER+, TER+ and CT, respectively. Mean soil losses were 4t ha-1 y-1 in DER+, 13 in TER+ and 18 in CT. Soil water storage during the growing season was constantlyhigher in CA-based systems compared with CT. A period of at least three years of cropping was required beforeimprovements in crop yield became significant. Further, modeling of the sediment budgets shows that total soilloss due to sheet and rill erosion in cropland, when CA would be practiced at large scale in a 180 ha catchment,would reduce to 581 t y-1, instead of 1109 t y-1 under the current farmer practice. Using NASA/GISS Model IIprecipitation projections of IPCC scenario A1FI, CA is estimated to reduce soil loss and runoff and mitigate theeffect of increased rainfall due to climate change. For smallholder farmers in semi-arid agro-ecosystems, CA-basedsystems constitute a field rainwater and soil conservation improvement strategy that enhances crop and economicproductivity and reduces siltation of reservoirs, especially under changing climate. The reduction in draught powerrequirement would enable a reduction in oxen density and crop residue demand for livestock feed, which wouldencourage smallholder farmers to increase biomass return to the soil. Adoption of CA-based systems in the studyarea requires further work to improve smallholder farmers’ awareness on benefits, to guarantee high standardsduring implementation and to design appropriate weed management strategies.

Eight years of conservation agriculture-based cropping systems research in Eastern Africa to conserve soil and water and mitigate effects of climate change

https://biblio.ugent.be/publication/4419456/file/4419460

Eight years of conservation agriculture-based cropping systems research in Eastern Africa to conserve soil and water and mitigate effects of climate change

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