Effects of drip irrigation frequency on the farmland soil water-heat distribution and spring maize growth in North China

Effects of drip irrigation frequency on soil water-heat distribution and root distribution and yield of spring maize were analyzed on the basis of the lower limits of optimum soil moisture and the same irrigation quota in Beijing District, where irrigation model was combined field irrigation of spring maize with precipitation. The results show that, under each drip irrigation treatment before the tasselling stage of spring maize, the fluctuation of average soil water content and soil matric potential at different soil depthes are comparative low under high frequency drip irrigation treatment (HDI), and the HDI can hold stable soil water content. The drip irrigation can obviously delay the effect of air temperature on the soil temperature, which was influenced by irrigation process, soil water content and crop growth stages. In addition, the irrigation frequency affects the spring maize root distribution in the soil, and the HDI improves the probability of root distribution in upper soil(0~40 cm). The yield difference of spring maize for irrigation frequency treatments is not significant under the typical field irrigation model combined irrigation with precipitation. Therefore, the low frequency drip irrigation method should be recommended for spring maize in North China under such irrigation model.