北疆棉田不同冬灌方式下的土壤水、盐分布的特点及适宜灌水定额

摘要

新疆地处西北干旱区,水资源严重不足,为探寻解决干旱区棉田冬季灌水问题,明晰北疆滴灌棉田不同灌水方式下冬灌灌水定额及其对水分、盐分和温度的影响,通过田间试验,从土壤的水分、盐分、灌水定额等综合调控以及非冬灌棉田作为对照(CK),设置滴灌和漫灌2种灌水方式,5个梯度的灌水定额(1200,1800,2400,3000,3600 m3/hm2)进行冬灌试验;通过对滴灌、漫灌和非冬灌的对比以及不同灌溉定额对水分、盐分的变化情况的分析,结果表明,冬灌对土壤水盐分布和含量的大小均有一定的影响,滴灌和漫灌均随灌水定额的增加,土壤水分和盐分影响深度随之加深,灌水定额为1200~2400 m3/hm2土壤水盐影响深度在150 cm左右,灌水定额为3000~3600 m3/hm2土壤水盐影响深度达到300 cm,滴灌和漫灌均有效淋洗并降低上层土壤盐分含量;相对漫灌方式而言,滴灌冬灌方式土壤水分入渗均匀和洗盐效果明显.综合考虑,在冬灌条件下,不同灌水方式的优劣秩序是:滴灌漫灌非冬灌;大定额灌溉比小定额灌溉(1200~2400 m3/hm2)保水储水更好,且洗盐压盐的效果更明显;综合水盐运移的复杂性以及洗盐效果,初步确定滴灌方式下灌溉定额为3000 m3/hm2为宜.%Xinjiang is located in the Northwest Arid Areas,a serious shortage of water resources,to solve the problem of cotton winter irrigation in arid areas,clear drip irrigation cotton fields of Northern Xinjiang winter irrigation irrigation quota under different irrigation methods and its influence on water,salinity and temperature,through field experiment,the soil moisture,salt,and irrigation quota and so on comprehensive control,and the not winter irrigation cotton as the control (CK),set the drip irrigation and flood irrigation mode,five gradient irrigation quota (1 200, 1 800,3 600,3 000,3 600 m3/ha) winter irrigation experiment was carried out. Winter irrigation in drip irrigation, flood irrigation,and through the contrast and the different irrigation quota on the analysis of the change of water,salt, the results showed that the winter irrigation on soil water and salt distribution and content all had certain influence, the size of the drip irrigation and flood irrigation with the increase of the irrigation quota,soil water and salt deepen influenced depth,irrigation quota on soil water and salt in 1 200-2 400 m3/ha influenced depth at 150 cm,irrigation quota on soil water and salt in 3 000-3 600 m3/ha influenced depth of 300 cm,drip irrigation and flood irrigation were effective leaching upper and lower soil salt content;Compared with the flood irrigation method,the soil water in-filtration uniform of drip irrigation mode and the rinsing salt were obvious. Comprebensive consideration,under the condition of winter irrigation,the superiority of different irrigation methods was drip irrigation flood irrigation not winter irrigation;Big ration irrigation was better than small quota of irrigation(1 200-2 400 m3/ha) water,salt and salt leaching pressure effect was more obvious; Synthesis of the complexity of the salt and water movement and salt leaching effect,preliminarily determine the drip irrigation quota under way was 3 000 m3/ha is advisable.