呼图壁县膜下滴灌棉花灌水时间研究

以大田不同滴灌管铺设方式下的滴灌棉花为对象,研究其最佳灌水时间。试验在同一灌区内不同滴灌管铺设模式下,通过滴头正下方开挖坡面,观察湿润锋的趋势及其随灌水时间的变化情况。结果表明:在大田膜下滴灌条件下,土壤水平湿润锋基本呈圆形分布;在一定灌水量和滴头流量条件下,土壤垂直湿润锋明显地大于水平湿润锋,且随着灌水时间的增大呈二项式关系,拟合公式R~2均大于0.98;由此可以确定该地区滴灌棉花一膜两管方式的滴灌棉花灌水时间8h为合理,一膜三管方式滴灌棉花灌水时间6h较为合理。

Study on Irrigation Time for Cotton with Drip Irrigation Under Mulch in Hutubi County

In this study,the field cotton under drip irrigation with different pipe layout types is taken as a studying obj ect to study its optimal irrigation time.The test is conducted in the same irrigation district with different pipes layout type.A slope is excavated j ust below the emitter to observe the tendency of wetting front and its change with irrigation time.The results show that:under the con-dition of field drip irrigation under mulch,the soil horizontal wetting front substantially presents circular distribution;under the con-dition of certain irrigation quantity and emitter flow,the soil vertical wetting front is significantly larger than the horizontal wetting front and presents binomial relations with the increase of irrigation time,and the R2 of fitting formula is greater than 0.98.So it can be concluded that in the study area,the optimal irrigation time for drip irrigation cotton is 8 hours and 6 hours,respectively,for the layout type of a film with two pipes and the layout type of a film with three pipes.