免耕轮作对内蒙古地区农田贮水特性和作物产量的影响

摘要

In 2005-2011, the effects of five tillage methods including no-tillage with high stubble mulching (NHS), no-tillage with low stubble mulching (NLS), no-tillage with high stubble (NH), no-tillage with low stubble (NL), and conventional tillage (T) combined with three rotation patterns(oat-soybean-corn, soybean-corn-oat, corn-oat-soybean) on water retaining properties and crop yield were studied in Qingshuihe county of Inner Mongolia. The results showed that no-tillage combined with rotations increased the soil water retaining capacity, and there was a positive correlation between soil water storage and rainfall. Among different treatments, the two no-tillage with stubble mulching combined with oat-soybean-corn rotation had the biggest effect to increase the soil water storage that was 35.66-41.63% higher as compared with conventional tillage. All the no-tillage methods combined with rotation patterns were able to increase crop water use efficiency and crop yield that was positively correlated with rainfall. After the first rotation cycle, compared with conventional tillage, the soil water use efficiency of NHS, NLS, NH, and NL increased by 43.77%, 31.45%, 26.74%, and 13.91%, the crop yield increased by 29.68%, 27.69%, 18.05%, and 15.66%. In the second rotation cycle, the drought was serious, which resulted in the decreased effects of no-tillage combined with oat-soybean-corn rotation, but the crop water use efficiency of NHS, NLS, NH and NL increased by 29.83%, 20.51%, 6.18%, and 3.15%, the crop yield increased by 17.52%, 13.60%, 4.33%, and 1.95%, as compared with conventional tillage. So in the arid area of Inner Mongolia where the rainfall is the major source of soil water, no-tillage combined with rotation can improve the ability of storing moisture in soil, and increase crop yield, especially the no-tillage with stubble mulching combined with oat-soybean-corn rotation.%2005-2011年,在内蒙古清水河县进行了免耕留高茬覆盖(NHS)、免耕留低茬覆盖(NLS)、免耕留高茬(NH)、免耕留低茬(NL)和常规耕作(T)5种耕作方式与3种轮作模式(燕麦-大豆-玉米、大豆-玉米-燕麦和玉米-燕麦-大豆)对土壤贮水特性和作物产量影响的研究.结果表明,不同免耕轮作处理中以免耕留茬覆盖结合燕麦-大豆-玉米轮作模式对土壤贮水量的提高程度最大,增幅为常规耕作的35.66％～41.63％.不同免耕轮作模式均能提高作物水分利用效率和作物产量,且作物产量高低与降雨量的变化趋势一致.第1个轮作周期后NHS、NLS、NH和NL分别较T作物水分利用效率增加43.77％、31.45％、26.74％和13.91％,作物产量增加29.68％、27.69％、18.05％和15.66％.第2个轮作周期内由于干旱比较严重,免耕方式结合燕麦-大豆-玉米模式效果较轮作第1个周期有所下降,但NHS、NLS、NH和NL仍分别较T作物水分利用效率增加29.83％、20.51％、6.18％和3.15％,作物产量增加17.52％、13.60％、4.33％和1.95％.因此,在土壤水分基本来源于自然降水的内蒙古旱作区,免耕轮作能够提高土壤蓄水保墒能力,增加作物产量,尤其以免耕秸秆覆盖结合燕麦-大豆-玉米模式效果最佳.