Effects of different field management practices on winter wheat yield and water utilization efficiency in Weibei Loess Plateau

Water is the main factor influencing crop yield in dryland areas, and the efficient way to increase crop yield is to improve utilization efficiency of precipitation. A two-year field experiment was conducted in Weibei Loess Plateau of Shaanxi Province to evaluate the effects of different field management practices on winter wheat yield and water utilization efficiency from Oct. 2001 to Oct. 2003. The soil is silty loam derived from loess soils. Field management practices in this experiment include full-time mulching with wheat straw, fallow crop planting during summer fallow, conventional practice (summer fallow after winter wheat), and bare soil. The results showed that different field management practices had significant effects on winter wheat yield and water utilization efficiency of winter wheat. First, mulching not only improved rainfall infiltration into soil and soil moisture, but also promoted soil moisture transport during wheat seedling period. Second, the yield of winter wheat was increased significantly compared with conventional treatment in the second year. Another advantage of mulching was demonstrated to increase soil organic matter content. Third, the use of fallow crops ploughed down into soil before sowing wheat did not greatly influence the quantity of water stored in the soil for use of the subsequent wheat crop. Furthermore, fallow crop did not increase soil organic matter content, wheat yield and water utilization efficiency of wheat during experimental years.