Characteristic Of Evaporetion And Transpiration In Winter Wheat/Spring Maize Intercropping System

Wheat/Maize Intercropping as a main cropping pattern is widely promoted in arid and semi-arid region of northwest China,but the high water consumption and high ratio of evaporation and evapotranspiration(E/ETc)restrict its large-scale application.This study was focused on winter wheat/spring maize Intercropping system,set different irrigations and corresponding monoculture treatments,there were three research directions in this study: Dynamic of soil moisture in winter wheat/spring maize Intercropping system,The compare of soil evaporation between winter wheat/spring maize Intercropping and corresponding monoculture,The separation of evapotranspiration and crop coefficient calculation of winter wheat/spring maize Intercropping.The main results were listed as follows:(1)Soil moisture content was difference in winter wheat/spring maize intercropping under three points with the development of crop growth.With the growth of wheat,soil moisture content of wheat lines were gradually reduce.And maize lines had the same change trend.Vertical soil moisture distribution was shown as: 0-40 cm soil moisture content increased with the increase of soil depth,40-50 cm slightly reduced,50-160 cm soil moisture content increase first and then decrease.(2)The soil evaporation of intercropping pattern at relatively high levels in each processing stage,and the movement of soil evaporation in monoculture is greater than intercropping pattern.The change of soil evaporation was obviously influenced by irrigation and rainfall,and the increase of soil evaporation had occurred after irrigation or rainfall.The peak of daily variation of soil evaporation in different points from 12:00 to 14:00,and it was obviously effected by solar radiation and surface coverage.It was a pulse wave change between soil evaporation and soil moisture content.Leaf area index(LAI)of intercropping pattern showed the tendency of the "two peaks",E/ETc was decreased with the increase of LAI and there was a negative exponential function relation between E/ETc and LAI.(3)The ETc and E/ETc in intercropping pattern were greater than monoculture,the Kc of intercropping pattern showed the tendency of the "two peaks" and the value were less than monoculture.The first peak appeared in the late of wheat + the development of maize,and the second peak appeared in the middle of spring maize.The order of cumulant of ETc in the whole growth period under different treatments were: WMI > WMN > SMI > SMN > SWI > SWN,the cumulant of E had the same order with ETc,but the order of cumulant of E/ETc was different,which was WMI > WMN > SMI > SMN > SWN > SWI.