隔畦灌溉适宜的土壤及灌水量研究

通过基于HYDRUS-2D模型所建模拟模型,模拟了不同土壤、灌水量和隔畦宽度情况下隔畦中不同深度土壤水分变化情况.基本结论为:①壤土侧渗效果最好,在灌水4～5 d后,灌溉畦与非灌溉畦(隔畦)土壤含水量基本接近,可达到隔畦灌溉的目的;②隔畦中湿润锋距离与灌水后时间呈线形关系;灌水畦灌水量越大,在窄畦中的湿润锋越远,但增大到1 050 m3/hm2以后因渗漏的增加,湿润锋距离增加不太明显;③综合考虑节水率、产量等因素,灌水量在600～900 m3/hm2之间,畦宽选择120 cm左右,灌水利用率最佳,与田间结果一致.项目研究结果为制定隔畦灌溉制度提供了基本参考依据.

Study on the Suitable Soil Conditions and Irrigation Water Quantity under Interval-border Irrigation

Through the simulation model based on HYDRUS-2D model, the changes of soil water content under different situations of soils, irrigation water quantity and interval-border width are studied in this paper. The main conclusions are as following. Firstly, the effect of side seepage in loam soil is the best among the three kinds of soils, in which the soil water content in irrigated-border and interval-border are very alike after irrigation 4-5 days. Secondly, the length of wetted front in interval-border has a linear relationship to the time after irrigation, and the more water irrigated, longer the wetted front, but the increase of the length is not notable when the water irrigated is more than 1 050 m^3 per hectare because of the vertical infiltration increases at the same time. Thirdly, comprehensively considering the factors of yield and water saving rate, the water use efficiency is the best in the cases that the irrigation water quantity is 600-900 m^3 per hectare and the width of interval-border is about 120 cm. The results provide basic reference to establish interval-border irrigation schemes.