Effect of spring wheat stubble treatments on grain yield and water use efficiency of multiple cropping rape

In order to reduce stubble burning, to control burning pollution and to increase usage of stubble remaining after harvest, a study was conducted to determine effects of different spring wheat stubble treatments on grain yield and water use efficiency (WUE) of multiple cropping rape from July to October in 2009. Three kind of treatments were standing stubble removed by burning, standing stubble with no-tillage, and tilled plots (conservational tillage), respectively. The results showed that the farmers can get a profit of 3?275 RMB/hm2 as planting rape in standing stubble treatment with no-tillage, compared with leaving land fallow. Grain yields with different treatments, standing stubble removed by burning, conservational tillage and standing stubble with no-tillage were 1?549, 1331 and 1?222 kg/hm2, respectively, while WUE were 5.73, 3.81 and 5.71 kg/hm2/mm, and profits were 4?485, 2?929 and 3?275 RMB/hm2, respectively. The treatment of rape planting in standing stubble removed by burning has the highest grain yield, WUE and profit among all treatments, and farmers can gain the maximum benefit, but the treatment was not good for environmental protection. Although the treatment of conservational tillage had a higher grain yield than the treatment of standing stubble with no-tillage, but it had a lower WUE and profit. The treatment of standing stubble with no-tillage could get a relatively high WUE and profit, and had benefits for environmental protection and for agricultural farming in arid and semiarid areas, so it is worth trial on a wider scale. Based on research results, the proper technique and optional planting parameters were proposed for mechanized multiple cropping rape on standing stubble field with no-tillage in oasis irrigation area of Shiyanghe River Basin, Northwestern China.