夏闲期玉米压青对旱地麦田土壤水分周年变化的影响

Effects of Maize Green Manure Returning Treatment in Summer Fallow Period on Annual Soil Moisture Variation in Dryland Wheat Field

[目的]揭示旱地麦田土壤水分对夏闲期玉米压青的周年适应变化规律,阐明压青模式对小麦产量提高及优化的水分驱动机制,为旱作压青蓄水技术提供理论参考。[方法]通过晋南旱地麦田夏闲期玉米压青还田试验,采用大区对比方法,以夏闲期免耕处理为对照,研究夏闲期玉米压青模式下麦田土壤周年贮水耗水变化规律,分析了其对后茬小麦产量的影响及水分利用效率。[结果]与免耕模式相比,夏闲期玉米压青处理可显著提高0—200 cm土壤周年贮水量,且对100—200 cm较深层土壤的蓄水能力更强;玉米压青处理0—200 cm土壤周年耗水量及耗水百分比均显著低于免耕处理;与免耕相比,压青处理可提高夏闲期0—200 cm土层盈水量,减少小麦季0—100 cm浅土层的水分耗散量;压青处理小麦穗数、穗粒数显著高于免耕,而千粒重差异较小;压青处理夏闲期0—200 cm土壤对降雨的蓄水效率显著高于免耕;在夏闲期玉米压青还田生物量显著高于免耕处理条件下,小麦季和周年阶段,压青处理生物产量及籽粒产量的降水、水分利用效率均显著高于免耕处理。[结论]在旱地麦田丰水年份,夏闲期玉米压青可显著提高旱地麦田土壤贮水,降低作物周年耗水量,优化小麦产量三要素,蓄水增产。

[Objective]The aims of this study are to reveal the annual adaptive change pattern of soil moisture in dryland wheat fields in response to maize manure returning in summer fallow period,to elucidate water-driven mechanisms for wheat yield improvement and optimization by maize manure returning patterns,and to provide the theoretical references for dry farming water storage technology.[Methods]Trials of maize manure returning in summer fallow period were carried out in southern Shanxi dryland wheat fields,which adopted a regional comparison method.The no-tillage treatment during the summer fallow period was used as a control.The annual wheat field′s soil water storage and consumption variation rules under summer fallow period maize manure returning were studied.Its effects on yield of succeeding wheat and efficiency of water use were also analyzed in this experiment.[Results]Compared to the no-tillage treatment,the treatment of maize manure returning in summer fallow period could significantly increase 0—200 cm soil annual water storage amounts,which also had a better soil water storage capacity in deeper layer.The amounts of 0—200 cm soil moisture consumption and water consumption percentage of maize manure returning treatment were significantly lower than those of no-tillage treatment.The manure returning treatment could improve 0—200 cm soil surplus water amounts during summer fallow period,and reduced 0—100 cm shallow soil layer′s water dissipation amounts compared with no-tillage pattern.The wheat spike number and kernels per spike of manure returning treatment were significantly higher than those of no-tillage pattern,but the difference of thousand-grain weight between two treatments was not significant.The efficiency of 0—200 cm soil layer water storage for rainfall under manure returning treatment was significantly higher than that of no-tillage pattern in summer fallow period.The returning field biomass in maize manure returning treatment was significantly greater than that of no-tillage pattern in summer fallow period.The biological yield′s precipitation and water use efficiency of maize manure returning treatment were significantly higher than those of no-tillage pattern in wheat season and anniversary stage.The same variation trend was observed in grain yield′s precipitation and water use efficiency.[Conclusion]In dryland wheat field humid years,the summer fallow period maize manure returning treatment could significantly improve soil water storage amounts of dryland wheat field,which also reduced crops annual water consumption and optimized the three elements of wheat yield.Finally,the maize green manure returning pattern will increase wheat yield by more soil impoundage.