不同措施对河套灌区重度盐渍土改良效果

Effects of Different Measures on the Improvement of Severe Saline Soil in Hetao Irrigation Area

为了探究不同灌溉模式施加不同改良剂对河套灌区重度盐渍土的改良效果,设置秸秆深埋(SL)、石膏+有机肥(SF)、对照(CK)3个处理,对河套灌区重度盐渍土土壤盐分在0-70 cm剖面上的分布特点进行研究。结果表明:不同灌溉模式,SL和SF处理在0-15 cm土层均有效降低土壤pH,随改良时间延长改良深度增加pH持续降低,有一定的长效性,滴灌SL与SF处理pH较CK分别下降0.35,0.49,黄灌下降0.42,1.33,对30-70 cm土层影响较小。SF处理碱化度第2年下降达43%,SL处理为40%,滴灌更利于碱化度降低。从抑制盐分积累来看,SL与SF处理能有效抑制盐分0-15 cm土层聚集,黄灌SL与SF处理较CK分别下降13.60%,7.70%,滴灌分别下降31.60%,6.90%,SL处理抑盐效果较显著。土壤盐基离子表明,不同灌溉模式,SL与SF处理均显著降低0-15 cm土层Na^+与HCO^3-的含量,滴灌降低比例高于黄灌,随着改良时间延长效果越显著,15-70 cm土层无明显变化。石膏加有机肥的施入提高0-70 cm土层SO 4^2-、Ca^2+及Cl^-的含量。通过对比分析,对河套灌区重度盐渍土治理而言,秸秆深埋和石膏+有机肥均能有效抑制重度盐渍土土壤积盐,有效降低pH及碱化度。整体来看,滴灌模式下石膏+有机肥改良效果优于秸秆深埋。

In order to explore the effects of different irrigation modes on the improvement of severe saline soil in Hetao Irrigation District,this experiment set up three treatments of straw deep burial(SL),gypsum+organic fertilizer(SF)and control(CK),and the distribution characteristics of soil salinity in the 0-70 cm profile of the soil were studied.The results showed that under different irrigation patterns,SL and SF effectively reduced soil pH in 0-15 cm soil layer,the pH decreased continuously with the extension of the treatment time and the increasing of improvement depth.Compared with CK,the pH of SL and SF under drip irrigation decreased by 0.35 and 0.49,respectively,and that of SL and SF under yellow river irrigation decreased by 0.42 and 1.33,respectively,while irrigation mode had little effect on 30-70 cm soil layer.The alkalinity of SF decreased by 43%in the second year and that of SL decreased by 40%,drip irrigation was beneficial to the reduction of alkalinity.In terms of inhibiting salt accumulation,SL and SF could effectively inhibit the aggregation of salt in 0—15 cm soil layer.Compared with CK,the salt of SL and SF under yellow river irrigation decreased by 13.60%and 7.70%,respectively,and that under drip irrigation decreased by 31.60%and 6.90%,respectively.SL had significant salt inhibition effect.The soil salt-based ions showed that the SL and SF significantly reduced the contents of Na^+ and HCO^3- in 0-15 cm soil layer under different irrigation modes,the reduction ratio of drip irrigation was higher than that of yellow river irrigation,and the effect was more obvious with the extension of the improvement time.While there was no significant change in 15-70 cm soil layer.The application of gypsum and organic fertilizer increased the contents of SO4^2-,Ca^2+and Cl^-in 0-70 cm soil layer.Through comparative analysis,for the treatment of severe saline soil in Hetao Irrigation Area,both deep burying and gypsum+organic fertilizer could effectively inhibit salt accumulation in severe saline soil,reduce pH and alkalinity.Overall,the improvement effect of gypsum+organic fertilizer under drip irrigation mode was better than the deep straw burial.