土壤改良剂对苏打盐化草甸土水盐运移特性的影响

Effects of Soil Ameliorant on Characteristics of Soil Water and Salt Movement in Soda-salinized Meadow Soil

为明确外源添加改良剂后苏打盐化草甸土不同深度土层的水盐运移特征,采用室内淋溶土柱试验方法,设置5个改良剂施用处理(CK、T1、T2、T3和T4),依据土柱内径折算用量分别为0.0,8.9,44.3,88.5和221.25 kg·hm^(-2),研究不同改良剂用量对不同土层水分累计入渗量、湿润峰运移深度和全盐含量的影响。结果表明:与未施改良剂处理(CK)相比,入渗时间为15000 min时,T1、T2、T3和T4处理累计入渗量分别增加158%、167%、205%和257%,湿润峰累计运移深度分别增加144%、145%、266%和369%;入渗时间为25000 min时,T1、T2、T3和T4处理累计入渗量分别增加140%、163%、200%和239%,T1、T2和T3处理湿润峰运移深度分别增加155%、176%和284%,T4处理湿润峰运移深度超50 cm(装土深度50 cm);入渗时间为37440 min时(入渗稳定),在20~50 cm土层,T3与T4含水量分别增加415%和471%,脱盐率分别增加512%和556%,三相比最接近理想值。针对本次供试土壤盐渍化程度,综合改良效果及改良剂施用量,改良剂适宜用量为T3处理的88.5 kg·hm^(-2),可达到最优淋洗效果。

Understanding the relationship between the application of a soil ameliorant and soda-salinized meadow soil was crucial to investigate the characteristics of soil water and salt movement on different depths of soil layers.In this experiment,we conducted a simulated leaching soil column experiment in laboratory,set up five ameliorants application rates treatments,0.0,8.9,44.3,88.5,221.25 kg·ha^(-1),defined as CK,T1,T2,T3 and T4,respectively.And we analyzed the cumulative amount of water infiltration,wetting front depth and full salt content at different soil layers,in order to clarify the characteristics of soil water and salt movement with the number of different amendments.The results showed that compared with CK,when the infiltration time was 15000 min,the cumulative infiltration of T1,T2,T3 and T4 increased by 158%,167%,205%and 257%,the migration depth of wetting front of T1,T2,T3 and T4 increased by 144%,145%,266%and 369%,respectively.And when the infiltration time was 25000 min,the cumulative infiltration of T1,T2,T3 and T4 increased by 140%,163%,200%and 239%,the migration depth of wetting front with T4 reached 50 cm(the depth of soil loading is 50 cm).However,that of T1,T2 and T3 increased by 155%,176%and 284%,respectively.When the infiltration time was 37440 min(water infiltration tended to stop,and the test was terminated),compared with CK in 20-50 cm,the application of T3 and T4 treatment substantially increased the water content by 415%and 471%,increased the desalination rate by 512%and 556%,and the three-phase ratio was the closest to the ideal ratio.Based on comprehensive analysis of the effect of soil ameliorant on the characteristics of water and salt movement,according to the degree of soil salinity in this experiment,the optimum application rate for the specific soil salinization was proposed as T3 treatment of 88.5 kg·ha^(-1).