覆盖免耕在休闲期的节水和生育期的调温效应

对免耕覆盖、秸秆还田和常规耕作在休闲期的节水效果研究表明:在夏季休闲期,免耕覆盖比常规耕作多贮水30.62mm,比秸秆还田多23.91mm;在冬季储水灌溉期间,可将储水定额从2100m3/hm2减少到600和975m3/hm2。对春小麦生育期土壤表层,5、10、15、20和25cm处温度变化观测发现:免耕覆盖土壤温度在气温较低的8:00可以提高土壤表层温度,在气温较高的14:00可以减缓土壤温度的升高,而在19:00气温降低时可以减缓土壤温度的降低,使土壤温度一直保持在一个稳定的状态,这有利于调节农田小气候,创造作物良好的生长环境。

Effects of no-tillage with straw mulch on water saving during fallow and soil temperature regulation in growing season

Effect of water saving was studied under no-tillage with straw mulch (NTS), conventional tillage with straw incorporated(CTS)and conventional tillage on bare ground(CTB). The results showed that NTS increased soil water storage by 30.6 mm and 23.9 mm over CTS and CTB during summer fallow. The winter storage irrigation quotas decreased from 2100 m3/hm2 to 600 m3/hm2 for CTS and 975 m3/hm2 for CTB. The soil temperature in 0～25 cm depth was monitored during growing period of spring wheat. NTS increased soil temperature in the morning when air temperature was low, but reduced the rate of temperature increment in the afternoon when air temperature was higher, and the rate of temperature decrement in the evening, therefore, keeping the stability of soil temperature. So NTS created a better micro-environment of field which was beneficial for the crop growth.