滴灌条件下沙地土壤水分分布与运移规律

Water Distribution and transport in sandy soil under drip Irrigation

通过对不同流量的滴头，不同灌水历时条件下沙地土壤滴灌湿润体的大小与形状的观测观察，以及对滴灌停止后不同间隔时间的土壤湿润锋运移，湿润体的发展，土壤水分的分布与再分布测量分析，使之对滴灌条件下土壤湿润体的大小及发展、土壤水分的分布与再分布规律等有了比较清楚的认识。本文不进行理论上的土壤水分分布模拟，仅从众多的实测资料分析着手，揭示土壤水分分布与运移规律，旨在为砂壤地玉米滴灌的参数确定（滴头间距、流量、灌水历时等）提供基本依据。通过土壤水分与湿润体实测资料分析认为，滴灌玉米的滴头流量在２．０ｌ／ｈ左右，灌水历时２～３ｈ，滴头间距为５０ｃｍ左右为宜。过长的灌水历时（大于３ｈ）即可能导致灌溉水的无为损失，造成先进的节水灌溉技术条件下新的水浪费问题。滴头间距过密，会加大不必要的工程投资。

By observing the transfer of wet front, the development of wetted soil body during a irrigation, as well as the final forms and sizes of wetted soil body under different dripping rates and duration, the water distribution and redistribution in sandy soil under drip irrigation were analyzed systematically. Based on a great deal of on the spot data, this paper reveals the water distribution and transport laws under drip irrigation in sandy soil. Field experimental results show that the optimal parameters of a drip irrigation system for corn in Inter Mongolia Autonomous Region can be set as: emitter space is about 50 cm, emitting rate per emitter is about 2.0 L/hr, and duration time is 2￣3 hr for a irrigation.