绿洲灌区耕作方式与秸秆还田对玉米田水热特征的调控效应

为探讨干旱绿洲灌区耕作方式与秸秆还田对玉米田土壤水热特征的调控效应，基于甘肃河西绿洲灌区田间定位试验，研究耕作方式(免耕、传统翻耕)和秸秆还田方式(秸秆还田、秸秆不还田)下农田土壤水分、温度动态变化特征。结果表明，耕作方式、秸秆还田显著影响土壤贮水量、耗水量、土壤温度、土壤有效积温、玉米籽粒产量、水分利用效率及积温生产效率，且互作效应显著。较秸秆不还田，秸秆还田提高了玉米各生育期0～120 cm土层的土壤贮水量，降低了玉米拔节至成熟期耗水量、播种至拔节期与吐丝期0～25 cm土层的土壤温度及各生育期土壤有效积温。免耕较传统翻耕提高了玉米拔节前土壤贮水量，降低了拔节至吐丝期耗水量，而传统翻耕较免耕提高了玉米各生育期土壤温度及有效积温。秸秆还田条件下玉米籽粒产量、水分利用效率及积温生产效率较秸秆不还田分别提高20.3%、23.6%和23.2%。传统翻耕的玉米籽粒产量、水分利用效率及积温生产效率较免耕分别提高20.8%、22.6%和12.3%。传统翻耕结合秸秆还田降低了玉米拔节前、吐丝至成熟期的耗水量，提高了各生育期土壤温度与有效积温。传统翻耕结合秸秆还田的玉米籽粒产量、水分利用效率及积温生产效率较其他处理分别提高20.3%～37.9%、22.0%～40.5%和7.0%～32.4%。因此，传统翻耕结合秸秆还田是绿洲灌区玉米高产、农田水热资源高效利用的理想耕作措施。

Effects of Tillage and Straw Returning Management on Soil Hydrothermal Characteristics in Maize Field of Oasis Irrigated Area

To explore the regulation effects of tillage and straw returning management on soil hydrothermal characteristics in maize fields of the arid oasis irrigated area,a field experiment was conducted in Hexi oasis irrigated area of Wuwei in Gansu province for determining the dynamic characteristics of field soil moisture and temperature under different tillage measures (no-tillage,conventional plough tillage) and straw returning methods (straw returning to the field,no straw returning). The results showed that different tillage and straw returning methods significantly affected soil water storage,water consumption,soil temperature,soil effective accumulated temperature,maize grain yield,water use efficiency and accumulated temperature production efficiency,and its interaction was significant. Compared with no straw returning,straw returning to field increased the soil water storage capacity in 0-120 cm soil depth at each growth period of maize,and reduced the maize water consumption from jointing to maturity stage,decreased the temperature in 0-25 cm depth soil from sowing to the jointing and the silking stage,and decreased effective accumulated temperature in each growth period. Compared with conventional plough tillage,no-tillage increased the soil water storage capacity before jointing of maize,reduced water consumption of maize from jointing to silking stages. Compared with no-tillage,conventional plough tillage increased the soil temperature and effective accumulated temperature in each growth period of maize. Compared with no straw returning,the straw returning increased maize grain yield,water use efficiency,and accumulated temperature production efficiency by 20.3%,23.6%,and 23.2%,respectively. Compared with no-tillage,the conventional plough tillage increased yield of maize grain ,water use efficiency,and accumulated temperature production efficiency by 20.8%,22.6%,and 12.3%,respectively.Combination of conventional plough tillage with straw returning reduced the water consumption before jointing and silking stages to maturity of maize,and increased the soil temperature and effective accumulated temperature in each growth period. Compared with other treatments,combination of conventional plough tillage with straw returning increased maize grain yield,water use efficiency and accumulated temperature production efficiency by 20.3%-37.9%,22.0%-40.5%,and 7.0%-32.4%,respectively. Therefore,combination of conventional plough tillage with straw returning is an ideal farming measure to increase maize yield,water and heat use efficiency in oasis irrigated area.