IMPACTS OF DIRECT SEEDING INTO MULCH ON THE YIELD, WATER USE EFFICIENCY AND NITROGEN DYNAMICS OF CORN, SORGHUM AND DURUM WHEAT

Direct seeding into mulch (DSM) is a cropping system that is increasingly used in the world. The major concern among producers is the possible yield penalties associated with DSM compared to conventional tillage (CT). The aim of our study was to assess the effects of DSM on the yields of corn, sorghum and durum wheat, as well as water use efficiency (WUE) and nitrogen dynamics. An experimental study was carried out at the Lavalette experimental station from 2001 to 2007. Corn, sorghum and durum wheat were sown in two tillage treatments (CT and DSM). Yield and some yield components, nitrogen dynamics and WUE were determined. The results showed that DSM could maintain the crop production of corn and sorghum, however, for durum wheat, CT performed better. DSM improved WUE and irrigation water use efficiency (IWUE) of corn and sorghum and decreased crop evapotranspiration from 5 to 27%. These results suggest that DSM is a relevant alternative to the CT system for corn and sorghum in the SE of France. Adopting DSM with a relevant crop rotation and cover crop resulting in a better IWUE for this system compared with CT can effectively address water scarcity issues in this region. Copyright © 2011 John Wiley & Sons, Ltd.