Analysis of Soil Moisture Changes in Arid and Semi-arid Areas by Soil Moisture Analyzer

The growth of crops in arid and semi-arid areas is limited by water, and the effective use of water can increase the yield of crops. Therefore, reasonable water and fertilizer management measures must be taken to fully understand the dynamic changes of farmland soil moisture, and provide a guarantee for the growth of crops. Effective irrigation measures. Soil layered water balance model is relatively simple, and in general it can reach a certain level of simulation accuracy. It is commonly used to simulate the dynamic changes of farmland moisture and to estimate or predict the irrigation water demand of farmland. For the soil moisture content can be measured using a soil moisture quick tester to obtain accurate test results.

The determination of soil moisture content by the soil moisture quickness tester found that when the soil moisture content is high, the evapotranspiration of the farmland is not affected by the soil moisture. However, when soil moisture content decreases, soil hydraulic conductivity decreases, water absorption rate of roots decreases, and crop transpiration and soil evaporation also decrease. The more serious the soil moisture deficit, the more significant the decrease in evapotranspiration. Therefore, the extent of soil moisture limitation evapotranspiration is expressed by the soil water stress coefficient.

The soil moisture dynamics of winter wheat and summer corn farmland are as follows: (a) The soil moisture content in the 1m soil layer of the winter wheat farmland varies greatly, and the soil moisture content in the 1m soil layer of the summer corn farmland changes little. This is mainly caused by staged irrigation of winter wheat farmland and abundant rainfall during the summer corn growth season. Before and after the start of the rainy season or after the end of the rainy season, the water content in the upper and lower layers of the summer corn farmland also differs greatly. (b) The active layer of roots in winter wheat farmland is mainly in the range of 0-40 cm, while the active layer of root activity in summer maize farmland is mainly in the range of 0-20 cm. Except for evaporation and precipitation and irrigation in the main root activity layer, In addition, water absorption in the roots is the main cause of drastic changes in water in this layer. (c) There are significant differences in the characteristics of soil water changes below the root layer of crops in the two types of farmland. For the winter wheat farmland, the water content in the soil layer below the root layer continuously decreases as water is continuously absorbed from the root to the maturity stage. The soil moisture content below the root layer of the summer maize field was not significantly different from that of the later period. Obviously, this was related to the irrigation measures, rainfall and distribution, and the distribution of crop roots in the crop growing season.

Using the results of the soil moisture quick-analysis instrument, the water dynamic characteristics of winter wheat and summer maize farmland were analyzed, and the change of soil moisture content was analyzed. The water variation rules of winter wheat and summer corn farmland were explored, and the model can also be used to estimate the actual farmland evapotranspiration. Quantity and soil layered root water absorption.