不同耕作措施对小麦水分利用的影响及机制

Effects of different tillage systems on water use of wheat

为探明在旱作雨养农业条件下不同耕作措施对小麦水分利用机制的影响，依托长期定位大田试验，于2012年比较研究了传统耕作（T）、免耕（NT）、免耕秸秆覆盖（NTS）和免耕地膜覆盖（NTP）条件下春小麦的阶段耗水量、抽穗期和灌浆期7：00时旗叶水势和各土壤层次的水分含量随不同生育期的变化及其对水分利用效率的影响．结果表明：免耕秸秆处理（NTS）相对于传统耕作处理（T）能提高全生育期0～30cm的土壤含水量和全生育期的作物耗水量（较传统耕作（T）提高5．45％），免耕秸秆覆盖（NTS）处理的抽穗期和灌浆期的7：00时旗叶水势相对于传统耕作（T）增加6．2％和4．6％，水分利用效率和籽粒产量高于传统耕作（T）处理11．2％和17．3％．采用免耕秸秆覆盖在增加作物耗水量的同时也提高了作物产量，所以免耕秸秆覆盖处理的水分利用效率最高．因此，在本试验条件下实施免耕秸秆覆盖的保护性耕作措施，有利于作物对有限降水的高效合理利用，提高作物产量．

Impacts of tillage treatments on phase and whole crop water use, water consumption intensi- ty, soil water dynamics along 200 cm profile,water potential of flag leaf in heading and filling,grain yield, and water use efficiency were studied based on a long term experiment initiated in 2001,including conven- tional tillage （T）, no-tillage （NT）, no-till with straw mulching （NTS）, no-till with plastic mulching （NTP）,to explore mechanism of tillage treatments on wheat water utilization in rain-fed environment, in 2012. Results showed that NTS increased soil water at 30 depth and water consumption （by 5.45%） as compared to T. NTS enhanced water potential at 7＂00 by 6. 2% in heading and 4. 6 ~ in filling, water use efficiency and grain yield of NTS were 11.2 ~ and 17. 3 % higher as compared to T, respectively. Adoption of NTS in this experiment improved crop water use, as well as grain yield, and resulting in the greatest WUE among treatments. Therefore,adopting NTS in rain-fed areas could enhance effective use of limited rainfall, and boost grain yield.