不同耕作措施对土壤水分和青贮夏玉米水分生产率的影响

Effects of different tillage methods on soil water content and water productivity of silage summer maize

适宜的耕作与覆盖措施可在不同程度节约农业用水。本文选用了翻耕处理、燃茬免耕处理和覆盖免耕处理为主要耕作措施,开展了为期2a的田间试验,研究不同措施对农田土壤含水量、土面蒸发、夏玉米生长指标、产量和水分生产率的影响。研究结果表明在降雨较少年份(2010年),覆盖免耕处理0～20cm土壤含水量均高于其他2处理,2a试验期间覆盖免耕处理0～120cm土壤贮水量一直高于其他2处理,且其土面蒸发量最小。2a试验期间,覆盖免耕青贮夏玉米产量较翻耕和燃茬免耕分别提高了11%和9%,青贮夏玉米水分生产率分别提高了11.7%和14.8%。覆盖免耕能减少土面蒸发和提高水分生产率,因此建议在北京地区夏玉米种植采用覆盖免耕措施。

Appropriate tillage and mulching practices can reduce soil evaporation and crop evapotranspiration, hence save irrigation water. Three widely used tillage methods, tillage （T treatment）, stubble mulching without tillage （C treatment） and stubble burning without tillage （B treatment） were chosen to analysis the effect of these methods on soil water, soil evaporation, crops＇ growth, silage maize yield and water productivity. The results showed that with less rainfall amount in the 2010 season, soil water content in 0-20 cm in Treatment C was higher than those in T and B treatments. The amount of soil water stored in 0-120 soil layer in C treatment was higher than those in T and B treatments in both seasons. Soil evaporation in C treatment was the least as compared to the other two treatments. Silage maize yields under C treatment were higher by 11% and 9%, and water productivity was higher by 11.7% and 14.8% as compared to T and B treatments, respectively. In a conclusion, stubble mulching without tillage was a appropriate practice for reducing soil evaporation and increasing water productivity, and then was recommended as a optimal tillage practice for maize cultivation in Beijing area.