华北地区滴灌灌水频率对春玉米生长和农田土壤水热分布的影响

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

针对华北地区春玉米田间灌溉和降雨相结合的灌溉模式,以北京为典型试验区,在保证作物最优土壤水分下限和灌溉定额相同的基础上,研究了滴灌灌水频率对土壤水、热分布及春玉米根系分布和产量的影响。试验结果表明:在春玉米抽雄期以前阶段实施的滴灌各处理中,高频滴灌下土壤平均含水率和不同深度处的土壤基质势波动幅度较小,高频滴灌下土壤水分能保持在一个比较稳定的范围;土壤温度受灌水过程、土壤含水率及作物生育阶段的影响较明显,滴灌能显著延迟气温对土壤温度的影响;灌水频率对春玉米根系分布存在一定影响,高频灌溉能显著促进春玉米根系在上层土壤(0～40 cm)中的分布;此外,在这种典型的灌溉和降雨相结合灌溉模式下,不同灌水频率下玉米产量差异不显著。因此,建议华北地区春玉米滴灌模式采用低频滴灌。

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.