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Master of farmland soil moisture variation , the dynamic change of farmland soil moisture to make predictions , is of great significance to improve the defense capabilities of agricultural drought , the development of water-saving irrigation schemes to improve water use efficiency . The production of winter wheat , Xia Wang meters climatic conditions analysis, analyzes of precipitation and soil moisture on the production of the two crops . Zhengzhou, Nanyang moisture measurement point soil moisture variation , interannual variations of soil moisture fall moisture slow decline of a relatively stable period in winter and spring, the rapid decline in the period , and increased moisture in period of four stages in the summer , using the regression the analysis method to establish the four periods of 0 ~ 50cm 0 ~ 100cm soil moisture conversion equation . Definition of the concept of soil water deficit index Penman-Monteith formula for the calculation of the reference crop water consumption formula , crop coefficient , soil water stress coefficient and crop water consumption based on the calculation to determine the soil water deficit index calculated calculated using the method of winter wheat from October 1995 to September 1996 , the major developmental stages of the summer corn soil relative humidity and soil moisture deficit index and draw two maps . According to the Henan crop distribution , climatic characteristics , soil type , Henan Province is divided into six district southwest of northern Henan , Yudong , western Henan , Henan , Central South , south of Henan Province and Henan , the use of the 1995 to 2004 a total of 10 years of soil moisture data , analysis of the frequency distribution of different soil moisture level of each partition during development of the crop . Based on the analysis of soil moisture variation , according to the soil water balance equation , winter wheat , summer corn soil moisture dynamic forecasting model . Inspection by the model , the accuracy is ± 8% .
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