Dryland soil water storage susceptibility to different soil tillage practices under Vetch-Wheat crop rotation

Crop rotation and soil tillage are two practices which would result in better use of water resources. So in order to investigate the effects of different crop rotation and soil tillage practices on soil water storage, a multi-annual experiment employing two crop rotations and six tillage practices was carried out in dry-land condition of Maragheh, northwest of Iran during year 2007 till 2011. Results showed that autumn cultivation of the common vetch (CR1) compared to spring cultivation of the common vetch (CR2) left more water in the soil for the following wheat cropping in the next years and subsequently increased biological and grain yield of wheat. It was also notified that the increase of water storage in second sampling depth (15-30 cm) was significantly more than two other depths (0-15 and 30-45 cm). Results also depicted that the tillage practice applying “chisel plough + cyclo-tiller + seed drill (TP1)” compared to other practices and especially the routine tillage of the region (moldboard plow + disk harrow + manual seed broadcasting, TP5) significantly increased soil water storage. The mentioned tillage practice (TP1) markedly decreased the bulk density of soil and increased biological and grain yield of wheat, as well. Therefore, applying TP1 tillage practice beside autumn cultivation of common vetch in rotation with wheat would be a good strategy to increase soil water storage and crop yield in dry-land conditions.