不同改良剂对河套灌区盐碱土入渗特性及水盐分布的影响

为对比研究改良剂对河套灌区盐碱土入渗特性及水盐分布的影响，设置对照组及2种施用水平(1%和2%)下的2种改良剂(生物炭和脱硫石膏)共5组处理，进行室内土柱试验。结果表明：(1)相比于对照组，1%施用量的生物炭能使入渗时间延缓8.9%,抑制水分入渗，降低相同时间内的土壤累积入渗量，2%施用量的生物炭对水分入渗过程起到先抑制后促进的作用，能使入渗时间缩短35.6%,2种施用量的脱硫石膏都能使入渗时间缩短91.1%,促进水分入渗，提高相同时间内的累积入渗量；只有2%施用量的生物炭使最终的累积入渗量大幅增加62.8%。(2)湿润锋运移距离与时间呈幂函数关系，用Kostiakov模型对累积入渗量和时间的关系拟合相对于Philip模型效果更好。(3)相比于对照组，只有1%施用量的生物炭使入渗后的土壤含水率降低2.7%,其余各处理均出现不同程度的增加；2种施用量的生物炭分别使入渗后的土壤含盐量显著降低28.5%和52.0%,但2种施用量的脱硫石膏分别使土壤表层含盐量显著提高184.3%和403.7%,其中2%施用量处理使土壤整体平均含盐量显著提高73.0%。综合考虑各处理改良后的入渗特性、土壤含水率...

Effects of Different Amendments on Infiltration Characteristics and Soil Water and Salt Distribution of Saline-alkali Soil in Hetao Irrigation District

In order to study the effect of amendments on infiltration characteristics and water and salt distribution of saline-alkali soil in Hetao Irrigation District, soil column experiment was carried out under five experimental conditions: control group and two contents (1% and 2%) of two modifiers (biochar and desulfurized gypsum). The results showed that: (1) Compared to the control group, 1% biochar made the infiltration time delay 8.9%, inhibited water infiltration, and reduced the amount of cumulative infiltration on the same time, while 2% biochar firstly inhibited and then promoted the process of infiltration, and it made the infiltration time shortened by 35.6%. Both desulfurized gypsum made the infiltration time shortened by 91.1%. They effectively promoted water infiltration and increased the amount of cumulative infiltration on the same time; Only 2% biochar significantly increased the final cumulative infiltration by 62.7%. (2) There was a power function relationship between the migration distance of wet front and time. Kostiakov model described the relationship between cumulative infiltration and time better than Philip model. (3) Compared to the control group, only 1% biochar reduced the soil moisture content by 2.7% after infiltration, while the other treatments had varying degrees of increase. The two application rates of biochar significantly reduced the soil salt content by 28.5% and 52.0%, respectively. However, the two contents of desulfurized gypsum significantly increased the soil surface salt content by 184.3% and 403.7%, respectively. The 2% application rate significantly increased the overall average soil salt content by 73.0%. By comprehensive consideration of the infiltration characteristics, soil moisture content and desalting effect of each treatment, biochar under the content of 2% is more suitable to improve saline-alkali soil in Hetao Irrigation District.