不同耕作方式对旱作冬小麦旗叶衰老和籽粒产量的影响

在旱作条件下研究了一次深翻、免耕、深松和传统耕作4种耕作方式对冬小麦花后旗叶衰老、小麦籽粒产量及土壤水分和养分状况的影响.结果表明：免耕和深松提高了小麦旗叶SOD和POD活性及可溶性蛋白和叶绿素含量，降低了MDA和O₂^-·含量，延缓了小麦叶片的衰老进程;同时，免耕、深松在开花期和灌浆期0～40 cm土层土壤水分含量分别比传统耕作提高了4.13％、6.23％和5.50％、9.27％，土壤碱解氮、速效磷和速效钾含量均显著高于传统耕作.一次深翻0～40 cm土层土壤水分含量低于传统耕作，土壤养分含量高于传统耕作，但两处理间差异不显著.与传统耕作相比，免耕和深松花后干物质生产量分别提高4.34％和4.76％，花后干物质转运率分别提高15.56％和13.51％，产量分别提高10.22％和9.26%.免耕和深松为冬小麦花后生长发育提供了良好的环境，延缓了小麦叶片衰老，促进了花后干物质积累及干物质向籽粒的转运，从而使籽粒产量显著提高，是旱作麦区适宜的耕作方式.

Effects of tillage pattern on the flag leaf senescence and grain yield of winter wheat under dry farming.

A field experiment was conducted to study the effects of different tillage patterns, i.e., deep plowing once, no-tillage, subsoiling, and conventional tillage, on the flag leaf senescence and grain yield of winter wheat, as well as the soil moisture and nutrient status under dry farming. No-tillage and subsoiling increased the SOD and POD activities and the chlorophyll and soluble protein contents, decreased the MDA and O〖SX（B-*3〗-〖〗·〖SX）〗2 contents, and postponed the senescence of flag leaf. Under non-tillage and subsoiling, the moisture content in 0〖KG-*2〗-〖KG-*7〗40 cm soil layer at anthesis and grain-filling stages was decreased by 413% and 623% and by 550% and 927%, respectively, and the contents of alkali-hydrolysable N, available P, and available K in this soil layer also increased significantly, compared with those under conventional tillage. Deep plowing once decreased the moisture content and increased the nutrients contents in 0〖KG-*2〗-〖KG-*7〗40 cm soil layer, but the decrement and increment were not significant. The post-anthesis biomass, post-anthesis dry matter translocation rate, and grain yield under no-tillage and subsoiling were 434% and 476%, 1556% and 1351%, and 1022% and 926% higher than those under conventional tillage, respectively. It could be concluded that no-tillage and subsoiling provided better soil conditions for the post-anthesis growth of winter wheat, under which, the flag leaf senescence postponed, post-anthesis dry matter accumulation and translocation accelerated, and grain yield increased significantly, being the feasible tillage practices in dry farming winter wheat areas.