微咸水波涌畦灌对土壤水盐分布的影响

根据2005年在中国科学院南皮生态农业试验站的田间试验结果,对灌溉后土壤剖面和沿畦长方向的水盐分布进行了研究.结果表明,当灌水量相同时,灌水结束后波涌灌和连续灌0～100 cm土层含水率在整个畦田上存在较大差别.比较灌水均匀度的结果可知,供水时间为90 min时,N=3,r=1/2,T_(on)=30 min的处理含水率离散程度最小,灌水均匀度最满意.从主根区含盐量的变差系数来看,连续灌明显高于波涌灌,说明微咸水的波涌灌在畦首到畦尾的盐分分布离散程度低于连续灌.因此灌水方式的改变在不增加灌水量的条件下改善了土壤水盐分布状况.

Effect of Saline Water Surge Flow Border Irrigation on Soil Water-salt Distribution

Based on field experiment in Nanpi ecological experimental station of Chinese Academy of Sciences, the soil water salt distribution of post-irrigation both on soil profile and along the border was studied. The results showed that, when precipitation rate was the same, the moisture content in 0～100 cm soil layer presented difference between surge flow irrigation and continuous irrigation. The uniformity of water application was compared, and the best irrigation condition was observed when all water supply period were 90 min, which was N=3, r=1/2, and T_(on)=30 min. Meanwhile the soil moisture content had minimal dispersion degree, and the uniformity of water application was the most satisfactory. The taproot region salt content of continuous irrigation was apparently higher than surge flow irrigation from variation coefficient, which means that the salt distribution dispersion degree of surge flow irrigation was lower than that of continuous irrigation from border initial to border end. Changing irrigation method from continuous irrigation to surge flow irrigation can improve water salt distribution pattern under the condition of same precipitation rate.