Influence of Soil Physical Properties on Salt Content in Soil Profile of Farmland in Weibei Region
FAN Huimin;XU Mingxiang;LI Binbin;ZHANG Rongrong;ZHANG Shengmin;MA Luyang;Research Center of Institute of Soil and Water Conservation and Ecological Environment,Chinese Academy of Sciences and Ministry of Education;College of Forestry,Northwest A&F University;College of Natural Resources and Environment,Northwest A&F University;
Soil salinization is an important type of soil degradation,which seriously restricts the development of agricultural production.Weibei region is the second granary of Shaanxi province.However,due to the higher groundwater level and salinity,the region is suffering from soil salinization,big waterlogging disasters,and high soil compaction for a long time.In order to analyze the influences of soil physical properties,such as water-stable aggregate,soil bulk density and soil texture on salt distribution in soil profile,soil samples were collected from typical farmland in Weibei region through 10km×10km mesh point method.The results showed that:(1)Soil salinization in Weibei region was not very serious but at a high potential risk.The proportion of mild salinized soil accounted for 46.56%,while the moderate salinized soil only23.01%.(2)Soil salt content increased with the increasing of soil depths in the profile,which indicated that the soil salt would be accumulated to the topsoil with water evaporation in improper managements.Strong negative correlation was observed between water-stable aggregate and soil salt content in the studied profiles.While,the correlation between soil bulk density and salt content varied with the degree of soil salinization.The influence of water-stable aggregate on salt content in topsoil was stronger than that of soil bulk density.However,significant correlation occurred between soil texture and salt content only in 0—20cm soil layer.(3)The effect of soil physical properties on salt content was not only found in the same soil layers but also in different soil layers.Namely,the ectopic impact was found in the influence of soil physical properties on salt content,and this impact was related to the degree of soil salinization.When salt content was lower than 1g/kg,apower function relationship was observed between soil bulk density in 40—60cm layer and saltcontent in 20—40cm layer.An increasing function was observed between soil bulk density in 20—40cm layer and salt content in 0—20cm layer when salt content ranged from 2g/kg to 4g/kg.However,when salt content was higher than 2g/kg,a decreasing function would be found between soil bulk density in 0—20cm layer and salt content in 20—40cm layer.A decreasing function was observed between water-stable aggregate and salt content,especially when salt content was higher than 2g/kg.
【Fund】： 中国科学院重点部署项目(KJZD-EW-TZ-G10);; 科技基础性工作专项(2014FY210100)
【CateGory Index】： S156.4
【CateGory Index】： S156.4