Effect Of No-tillage With Straw Mulch On Pea (Pisum Sativum L.) Under Storage Irrigationin In Hexi Irrigation District

The effect of no-till with straw mulch on the dynamics of soil moisture, soil temperature and pea (Pisum sativum L.) yield and its components was studied in Hexi irrigation district. The experiment was a split design with the main plot as tillage and the subplot as storage irrigation quota. The major conclusions from the experiment are as follows:(1) The no-till with straw mulch (NTS) can clearly increase soil water storage and water use efficiency during summer fallow. Results showed that there was a positive relationship between soil evaporation and irrigation quota during winter fallow period. Thus, the irrigation quota can be reduced to some reasonable amount that was enough to ensure seed germination in spring to save water. The evaporation under NTS was the lowest in spring, but there was no difference between tillage treatments. It is also found that there was no significant difference in the evaporation between treatments.(2) During anthesis (earlyJune), the irrigation quota has no effect on soil water content. However, NTS has superior advantage in preserving soil moisture. Results showed that there was no relationship between evaporation and the quota of storage irrigation. During growing season, the evaporation on NTS is 7.46% and 6.63% lower than CTB and CTS, respectively. Thus, NTS can reduce water consumption during growing season, mainly at 0-30 cm soil layer where pea roots are distributed.(3) It was observed that the daily average soil temperature at 0-10 cm was above 4.0°C before 29th, March, thus it can be sown in early April. Soil temperature changed dramatically within 5cm from sowing to seed emergence. At this stage, soil heat was mainly transmitted downward. The soil temperature pattern within 24 hours was like a"S"shape, i.e convex at daytime and concave at night.(4) The soil temperature increased quickly at night at seedling stage. In the morning, there was no effect of lowering temperature on NTS. During stage of branching, the heat generated from soil organic matter from stubble retention has no effect on soil temperature at 0-10 cm, but soil temperature at 10-25 cm under CTS was the highest. The change of soil temperature was the...