摘要
苏打盐渍化土壤胶体吸附大量交换性Na+,造成土壤团聚体崩解,粘粒分散,阻塞土壤孔隙。改良苏打盐渍土需两步:一是提供钙源替换交换性Na+,二是排出盐分。本文研究了腐解玉米秸秆和脱硫石膏不同改良组合对苏打盐渍土淋洗脱盐效率影响。结果表明,所有改良处理均能改善土壤入渗,入渗速率大小为:脱硫石膏>脱硫石膏+腐解秸秆>腐解秸秆>对照;含脱硫石膏处理显著提高土壤饱和导水率(Ks),在短时间内腐解秸秆处理不能改善土壤导水性,在70 d后才有效果;腐解秸秆处理土壤含水率最高,材料保水性好;淋出液化学性质显示,各改良处理均能促进钠离子的淋洗;土壤化学性质显示,淋洗后各处理土壤盐分均显著下降;脱硫石膏和脱硫石膏+腐解秸秆处理与对照相比,土壤pH降低更显著;各改良处理土壤可溶性钠离子含量显著低于对照,并且土壤中可溶性钙镁等二价阳离子显著高于对照;各改良处理土壤钠吸附比(SAR)均显著低于对照组。
Saline-sodic soil colloids contain a large number of exchangeable sodium ions,leading to soil aggregates breakdown,clay dispersion and soil pores blocking.Saline-sodic soils improvement requires two processes,providing calcium source to exchange with sodium on soil surface and removing salt through leaching or drainage.In this study,we used corn straw and desulfurized gypsum to improve the saline-sodic soil,and investigated the effect of different treatments on the desalination efficiency of saline-sodic soil during leaching.The results showed that all the treatments improved soil infiltration,and the infiltration rate was in an order of desulfurized gypsum>desulfurized gypsum+decomposed straw>control.Compared with the control,the treatments with desulfurized gypsum significantly increased the saturated hydraulic conductivity of the soil.Decomposed straw treatment would not improve soil hydraulic conductivity right in short time after start of leaching,but increased soil hydraulic conductivity after 70 d.The moisture content with decomposed straw treatment was the highest,meaning the material was with good water retention.The leachate chemical properties showed that all the treatments enhanced sodium ions leaching.The soil chemical properties showed that the salt content of each treatment significantly decreased after leaching.The soil pH with desulfurized gypsum and combined application treatments were significantly lower than those with the control and straw treatment.The contents of soil soluble sodium with all improved treatments were significantly lower than that of the control,and the contents of divalent cations such as soluble calcium and magnesium in the soil were significantly higher than that of the control.After leaching,the soil sodium adsorption ratios with all improved treatments were significantly lower than that of the control.
作者
廖栩
杨帆
王志春
管清杰
何明良
安丰华
杨洪涛
赵丹丹
朱文东
LIAO Xu;YANG Fan;WANG Zhichun;GUAN Qingjie;HE Mingliang;AN Fenghua;YANG Hongtao;ZHAO Dandan;ZHU Wendong(Northeast Institute of Geography and Agroecology, CAS, Changchun 130102, China;Aerospace Kaitian Environmental Technology Co.,Ltd.Changsha 410000,China;Northeast Forestry University, Harbin 150040,China;Northeast Institute of Geography and Agroecology,CAS,Harbin 150081,China;University of Chinese Academy of Sciences, Beijing 100049,China)
出处
《土壤与作物》
2020年第1期74-82,共9页
Soils and Crops
基金
国家重点研发计划资助项目(2016YFC0501200)
国家自然科学基金资助项目(41571210,41771250)
吉林省科技发展计划项目(20180201012SF).
关键词
苏打盐渍土
腐解秸秆
脱硫石膏
淋洗
脱盐效率
saline-sodic soil
decomposed straw
desulfurized gypsum
leaching
desalination efficiency.
