为探究保护性耕作对陇中黄土高原旱作麦田蓄水保墒效果和产量形成的影响。在连续5 a田间试验的基础上,分析了陇中黄土高原旱作麦田从2019年8月至2020年8月一个耕作周期内,不同耕作措施（传统耕作T、秸秆覆盖TS,免耕NT和免耕秸秆覆盖NTS）对麦田休闲期蓄墒率、水分利用效率、春小麦干物质积累与转运、产量及农艺性状的影响。结果表明：（1） 与处理T相比,NTS处理提高了耕层土壤容重和含水量,提高了旱作麦田播种和收获期土壤蓄水量,使水分利用效率提高了48.18%、休闲期蓄墒率提高了5.70%;（2） NTS处理显著提高了春小麦叶面积指数、延缓了叶片的衰老,相比于TS和NT处理,NTS处理下花后干物质积累量分别提高了67.38%和32.14%,花后干物质贡献率分别提高了12.47%和6.61%;（3） NTS处理优化了产量构成因素、显著提高了春小麦产量,使产量达到了3243.30 kg∙hm^-2,比传统耕作（T）产量提高了49.32%;NTS处理改善了春小麦群体结构,显著提高了春小麦根系干重、株高和生物量,降低了根冠比,相关性分析表明水分利用效率、叶面积指数、根系干重的提高是促进小麦增产的重要原因。在本试验条件下,免耕秸秆覆盖是实现陇中黄土高原旱作麦田蓄水保墒及节水增产的最优耕作措施、值得在该地区推广应用。

The aim of this study was to explore the effects of conservation tillage on water storage, moisture conservation, and yield in dry-land wheat fields in the Loess Plateau of central Gansu province. Based on field experiments for five consecutive years, the effects of different tillage measures [traditional tillage (T), straw mulching (TS), no tillage (NT), and no tillage with straw mulching (NTS)] on the moisture-storage rate in the leisure period, water-use efficiency, dry matter accumulation and transport, yield, and agronomic characteristics of spring wheat in a farming cycle from August 2019 to August 2020 were analyzed. The results were as follows. (1) Compared with treatment T, the NTS treatment increased the soil bulk-density and water content in the plow layer, increased the soil water storage during the sowing and harvest periods in a dry-land wheat field, increased the water-use efficiency by 48.18%, and increased the moisture-storage rate in the leisure period by 5.70%. (2) The NTS treatment significantly increased the leaf area index and delayed the leaf senescence of spring wheat. Compared with the TS and NT treatments, the dry matter accumulation after anthesis under the NTS treatment increased by 67.38% and 32.14%, respectively, whereas the contribution rate of the dry matter after anthesis increased by 12.47% and 6.61%, respectively. (3) The NTS treatment optimized the yield components and significantly increased the yield of spring wheat to 3243.30 kg∙hm^-2, which was 49.32% higher than the yield of traditional tillage (T). In addition, the NTS treatment improved the population structure of spring wheat, as well as significantly increasing its root dry-weight, plant height, and biomass, while reducing its root-shoot ratio. Correlation analysis showed that the increased water-use efficiency, leaf area index, and root dry-weight were important factors in the increase of wheat yield. In conclusion, under the conditions of this experiment, NTS mulching was the optimal tillage treatment in terms of saving water and increasing the yield of dry-land wheat fields in the Loess Plateau of central Gansu province. Thus, it may be worthwhile popularizing and applying the treatment in this area.