Effets du Système de Culture sous couverture Végétale (SCV) sur les flux hydriques d’un sol ferrugineux à l’Ouest du Burkina Faso

La faible disponibilite de l’eau de pluie et l’erosion, limitent les productions agricoles au Burkina Faso et necessitent de developper des systemes de culture innovants. L’etude a compare les effets du labour conventionnel et du semis direct sous couverture vegetale (SCV) sur les flux hydriques d’un sol au Burkina Faso. L’objectif etait de determiner la quantite de paille necessaire pour limiter l’erosion et ameliorer les caracteristiques hydriques du sol. Un dispositif agronomique randomise comprenant trois repetitions et trois traitements (T 0 = labour sans paillage, T 2t = semis direct sous 2t/ha de paillis et T 4t = semis direct sous 4t/ha de paillis) a ete utilise. Dans ce dispositif, une placette de 1,04 m² relie a un demi-fut place sous terre par un tuyau a permis de recueillir et de quantifier les eaux ruisselees et la terre erodee. La permeabilite des traitements a ete mesuree par la methode de l’infiltrometre a double anneaux. Pour mesurer l’humidite du sol, un echantillon par traitement et par horizon a ete seche a l’etuve pendant 24 heures a 105 °C. Les resultats montrent que le coefficient de ruissellement a varie de 55,27% a 16,3% sous SCV contre 94,1% sous labour sans paillage. Le SCV a reduit de 76 a 90% les pertes de terre, a significativement eleve la vitesse d’infiltration comparativement au labour (P=0,036) et a une meilleure humidite. La quantite de 2 t/ha de paillis est necessaire et suffisante pour controler le ruissellement et l’erosion, ameliorer l’infiltration et conserver une humidite suffisante comparativement au labour. © 2018 International Formulae Group. All rights reserved. Mots cles: Paillage, semis direct, labour, infiltration, humidite, ruissellement, erosion English Title:  Effects of Mulch based Crop Systems (MCS) on water fluxes of a ferruginous soil in the west of Burkina Faso English Abstract Agricultural productions in Burkina Faso are limited by the weak availability of the rainwater and the erosion. Systems of innovating culture are therefore to develop. The study compared the effects of the conventional ploughing and the direct seedling under plant cover (DSC) on the water fluxes of one soil in Burkina Faso. The objective was to determine the quantity of necessary straw to limit the erosion and to improve the water features of soil. A device agronomic random containing three repetitions and three treatments (T 0 = ploughing without mulch, T 2t = direct seedling under 2t/ha mulch and T 4t = direct seedling under 4t/ha mulch) has been used. In this device, a plot of 1.04 m² joined to a half stock placed under ground by a hose, permitted to collect and to quantify water streamed and the eroded soil. The permeability of the treatments has been measured by the method of infiltrometer with duplicate rings. To measure the humidity of soil, a middle sample by treatment and by horizon has been dried at the steam room during 24 hours to 105 °C. The results show that the coefficient of dripping varied from 55.27% to 16.3% under DSC against 94.1% under ploughing without mulch. The DSC reduced 76 to 90% the losses of soil, raised the speed of infiltration meaningfully compared with the ploughing (P=0.036) and has a better humidity. The quantity of 2t/ha of mulch is necessary and sufficient to control the dripping and the erosion, to improve the infiltration and to keep a sufficient humidity compared with the ploughing. © 2018 International Formulae Group. All rights reserved. Keywords: Mulch, direct seedling, ploughing, infiltration, humidity, dripping, erosion