Yin Wen, Chai Qiang, Guo Yao, Fan Hong, Fan Zhilong, Hu Falong, Zhao Cai, Yu Aizhong, Coulter Jeffrey A
Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou, China.
College of Agronomy, Gansu Agricultural University, Lanzhou, China.
Front Plant Sci. 2021 Apr 9;12:649684. doi: 10.3389/fpls.2021.649684. eCollection 2021.
Plastic is a valuable mulching measure for increasing crop productivity in arid environments; however, little is known about the main mechanism by which this valuable technology actuates spatial-temporal changes in soil hydrothermal effect. So a 3-year field experiment was conducted to optimize soil hydrothermal effect of maize field with three plastic mulched management treatments: (1) no tillage with plastic re-mulching (NM), (2) reduced tillage with plastic mulching (RM), and (3) conventional tillage with annual new plastic mulching (CM). The results showed that NM treatment increased soil water content by 6.6-8.4% from maize sowing to seedling stage, than did CM, and it created a good soil moisture environment for sowing of maize. Also, NM had greater soil water content by 4.8-5.6% from maize silking to early-filling stage than had CM, and it made up for the abundant demand of soil moisture for the vigorous growth of maize filling stage. The NM treatment increased water consumption (WC) before maize big-flare stage, decreased WC from big-flare to early-filling stage, and increased WC after early-filling stage. So NM treatment effectively coordinated water demand contradiction of maize at entire growing season. NM decreased soil accumulated temperature (SAT) by 7.0-13.0% at maize sowing to early-filling stage than did CM, but NM had little influence on the SAT during filling stage. In particular, the treatment on NM had smaller absolute values of air-soil temperature differences than RM and CM treatments during maize filling stage, indicating that NM treatment maintains the relative stability of soil temperature for ensuring grain filling of maize. The NM treatment allowed the maize to grow in a suitable hydrothermal status and still maintained high yield. In addition, NM treatment obtained higher net income and rate of return by 6.4-11.0% and 44.1-54.5%, respectively, than did CM, because NM treatment mainly decreased the input costs for plastic and machine operations. Therefore, the NM treatment can be recommended as a promising technique to overcome simultaneous heat stress and water shortage in arid environments.
地膜覆盖是干旱环境下提高作物产量的一项重要措施；然而，对于这项重要技术引发土壤水热效应时空变化的主要机制，人们了解甚少。因此，开展了一项为期3年的田间试验，采用三种地膜覆盖管理处理方式来优化玉米田的土壤水热效应：（1）免耕重覆地膜（NM），（2）少耕覆地膜（RM），（3）常规耕作每年换新地膜（CM）。结果表明，从玉米播种到苗期，NM处理的土壤含水量比CM处理提高了6.6 - 8.4%，为玉米播种创造了良好的土壤湿度环境。此外，从玉米抽丝期到灌浆初期，NM处理的土壤含水量比CM处理高4.8 - 5.6%，弥补了玉米灌浆期旺盛生长对土壤水分的大量需求。NM处理在玉米大喇叭口期前增加了耗水量（WC），在大喇叭口期到灌浆初期减少了WC，在灌浆初期后增加了WC。因此，NM处理有效协调了玉米整个生长季的需水矛盾。在玉米播种到灌浆初期，NM处理的土壤积温（SAT）比CM处理降低了7.0 - 13.0%，但NM处理对灌浆期的SAT影响较小。特别是在玉米灌浆期，NM处理的气-土温差绝对值比RM和CM处理小，表明NM处理保持了土壤温度的相对稳定性，以确保玉米灌浆。NM处理使玉米在适宜的水热状态下生长，并保持高产。此外，NM处理的纯收入和回报率分别比CM处理高6.4 - 11.0%和44.1 - 54.5%，因为NM处理主要降低了地膜和机械作业的投入成本。因此，NM处理可作为一种有前景的技术推荐，用于克服干旱环境中同时存在的热应激和缺水问题。
