春小麦留茬处理对复种油菜产量和水分利用效率的影响

为了减少麦茬焚烧、控制麦茬焚烧污染及提高留茬的利用效率，2009年7－10月在石羊河绿洲灌区进行不同留茬处理（焚烧、翻耕和立茬免耕）对麦茬复种油菜的研究。结果表明，与休闲地相比，立茬免耕复种油菜可获得利润 3?275元/hm2；焚烧、翻耕（传统耕作）和立茬免耕处理的油菜籽粒产量分别为1?549、1?331和1?222 kg/hm2，水分利用效率分别为5.73、3.81和5.71 kg/hm2/mm，经济效益分别为4?485、2?929和3?275元/hm2；仅从作物籽粒产量、水分利用效率和经济效益等方面考虑，秸秆焚烧处理达到最大值, 这就是焚烧屡禁不止的原因。尽管传统耕作的油菜籽粒产量高于立茬免耕，但传统耕作的水分利用效率和经济效益显著低于立茬免耕。立茬免耕具有环保、相对较高水分利用效率和经济效益等效果，尤其有利于环境保护和旱地农作，值得大面积推广。结合大田推广示范研究成果，提出适宜于石羊河绿洲灌区的留茬免耕机械直播复种油菜技术。

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.