| Soil erosion in the Loess Plateau is very serious, year-round in the region’s traditionalfarming methods on soil tilling, rake Mo, leading to soil erosion and nutrient loss, lowagricultural productivity. How to reduce the evaporation of surface runoff, increasing therole soil reservoir to improve crop yields in dryland agriculture is an important researchtopic. Based on this, the paper on the basis of the semi-arid Loess Plateau, Dingxi LeeTown on the long-term experiment to explore the dynamics of soil moisture in dryland cropsunder different cropping farmland in the Loess Plateau (wheat and pea rotation) differentconservation tillage measures under the change and its impact on crop yield. Include thefollowing four measures: conventional tillage (T), no-tillage (NT), conventional tillage strawmulching (TS), NTS (NTS). The results showed that:(1) conservation tillage can significantly improve the0~200cm soil water storage ofsoil in different cropping systems due to different rainfall year and showed different trends.The same process is almost no difference in different years, different treatment in the samelarge differences between years. Water storage in the crop growth stages of differenttreatments are not the same, Wâ†'Pâ†'W sequence under Sort crop sowing treatments forNTS> NT> T> TS, where NT, NTS than conventional tillage improved by0.24%,3.10%.Changes in storage capacity of each treatment Wâ†'Pâ†'W under the five-leaf stage of thecrop sequence NTS> T> TS> NT, the maximum storage capacity which NTS handle thanconventional tillage improved by2.04%. Wâ†'Pâ†'W flowering crops under eachtreatment sequence storage capacity variation of NTS> NT> T> TS, where NT, NTSrespectively, compared with conventional tillage improved0.30%,1.58%. Storage capacityof each treatment changes Wâ†'Pâ†'W next sequence crop maturity as NT> NTS> T> ST,where NT, NTS storage capacity of the storage capacity of traditional farming respectivelyincreased1.82%,1.21%. With the increase in precipitation, soil retention of precipitationstorage capacity enhancement. Less rainfall this year NTS prominent role in theperformance.(2) different conservation tillage a greater impact on the surface0~10cm soilmoisture content, tillage with straw mulch (NTS) in crop sowing sowing can significantly increase the surface soil moisture. Topsoil soil moisture due to rainfall and other factorsaffecting dramatic change, topsoil less soil moisture is relatively small amplitude. Sowing,harvesting five-leaf stage and have a high moisture content of the soil, and soil moisturewas lower flowering period. Each treatment under different sequences Wâ†'Pâ†'Wsequence under the average size of volumetric water content NTS> TS> NT> T. The averagevolumetric water content size Pâ†'Wâ†'P sequence is under NTS> NT> T> TS.(3) crops under conservation tillage and crop rotation systems can significantlyimprove crop yields, which straw mulch tillage crop production, crop water consumptionand water use efficiency higher relative to other treatments. Wâ†'Pâ†'W next sequence Pâ†'Wâ†'P sequence showed a maximum of NTS water consumption. Pâ†'Wâ†'P ratio Wâ†'Pâ†'W Water consumption NTS processing sequence is high. NTS treatment canincrease crop yields, Wâ†'Pâ†'W sequence under NTS respectively T, NT, TS improved18.88%,18.80%,10.34%. In the Pâ†'Wâ†'P sequence NTS respectively T, NT, TSimproved23.01%,31.08%,18.32%. NTS can improve water use efficiency of crops, Wâ†'Pâ†'W sequence processing under NTS respectively T, NT, TS improved18.49%,10.79%,11.20%. Pâ†'Wâ†'P under NTS processing sequence respectively T, NT, TSimproved17.80%,19.12%,15.88%. Therefore, in dry farmland for long-term conservationtillage can improve water use efficiency and crop yields. |
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