研究膜上灌水条件下,有无地下水补给的情况下,玉米田土壤水盐变化的特征。以宁夏引黄灌区石嘴山市惠农区玉米田土壤为研究对象,设置了有无地下水补给下膜上灌水与常规露地灌水2种灌溉方式,4个处理,每个处理重复3次,共12个试验小区,测定了玉米生育期间田间土壤的含水率和全盐量的变化情况、玉米产量及水分生产率。结果表明:在膜上灌水和露地灌水2种灌溉方式下,有地下水补给的处理土壤含水率显著高于无地下水补给的处理,全盐量也高于无地下水补给的处理;在无地下水补给的条件下,膜上灌水处理的土壤含水率显著高于露地灌水处理,有地下水补给的条件下,膜上灌水处理的全盐量显著低于露地灌水处理;土壤含水率及其不同处理之间的差值随土层的加深而增大,土壤全盐量的变异性随土层的加深而减小,露地灌水处理的全盐量变异性整体大于膜上灌水处理;土壤全盐量和含水率之间呈明显的负相关,且上层相关性更为密切。膜上灌水有利于玉米的生长,其产量和水分生产率高于露地灌水,有补给的小区玉米产量和作物系数高于无补给的,水分生产率低于无补给的小区。
In this study,we investigated the change characteristics of soil water and salt in the maize field under film hole irrigation,with and without groundwater replenishment.We sampled soils from the maize field in Huinong district,Shizuishan city,which was located in Yellow River irrigation area of Ningxia.4treatments were established,in which film hole irrigation and conventional bare soil surface irrigation were used,with and without groundwater replenishment,respectively.There were 3replications for each treatment.Therefore,there are 12 experiment plots in total,where the changes of soil water content and total salt content,maize yield and water productivity were measured during maize growing period.The results showed that soil water content and total salt content under both irrigation modes were obviously higher with groundwater replenishment than without it.When there was no groundwater replenishment,soil water content was higher under film hole irrigation than under bare soil surface irrigation,while total salt content in soil showed an opposite trend when groundwater was supplied.With the increase of soil depth,soil water content,as well as the difference of soil water content between different treatments,obviously increased,while the variability of soil total salt content reduced.The variability of soil total salt content was greater under bare soil surface irrigation than under film hole irrigation.Soil total salt content and soil water content were negatively correlated,especially in upper soil layers.Film hole irrigation can benefit growth of maize.The maize yield and water productivity were higher under film hole irrigation than under bare soil surface irrigation.The maize yield and crop coefficients with groundwater replenishment were higher than those without groundwater replenishment,while maize water productivity showed an opposite trend.