沼液穴灌土壤水分运移的交汇入渗特征

通过室内试验研究不同沼液浓度(原液与水的体积比为1∶4、1∶6、1∶8、CK)和穴孔直径(3、5、7 cm)对沼液穴灌土壤水分运移交汇入渗特征的影响。结果显示:相同入渗时间内,累积入渗量随沼液浓度的增大而减小;相同沼液浓度条件下,土壤水分累积入渗量随穴孔直径的增大而增大,土壤水分入渗速率随入渗距离的增大而减小;在相同穴孔直径及入渗位置,沼液浓度越大,土壤入渗速率越小;在相同入渗位置,随穴孔直径的增加,土壤入渗速率逐渐增加;Kostiakov入渗模型准确描述了累积入渗量随入渗时间增加而增加的关系,且模型拟合系数R2均大于0.99;沼液浓度相同时,土壤含水率为22%等值线以上的面积随着穴孔直径的增加而增大;土壤含水率为22%等值线以上的面积随沼液浓度的减小而增大。综合分析结果表明,沼液穴灌交汇入渗速率、累积入渗量及土壤含水率分布受沼液浓度、穴孔直径的影响。

Interference infiltration characteristics of the soil water movement under the hole irrigation with biogas slurry

Different concentration of biogas slurry (1∶4, 1∶6, 1∶8, and CK) and different diameters of soil hole condition(3, 5, 7 cm) were designed in the laboratory to investigate the characteristics of interference infiltration in soil under hole irrigation with biogas slurry. The results showed that the cumulative infiltration decreased with the concentration of biogas slurry increase during the same infiltration time, while they increased with diameters of soil hole at the same biogas slurry concentration; soil water infiltration rate decreased with the infiltration distance increase at the same biogas slurry level. The higher the concentration of biogas slurry, the lower the infiltration rate at the same diameter and infiltration distance. Infiltration rate increased gradually with the diameter of soil hole at the same infiltration sites. The case that the cumulative infiltration increased with time could be better described by Kostiakov infiltration model. The correlation coefficient (R2) from all treatments were larger than 0.99. The areas that soil water content larger than or equal to 22% increased with the diameters of soil hole, and they also increased with the biogas slurry decrease. These results demonstrated that the interference infiltration rate, cumulative infiltration and soil water content were jointly affected by biogas slurry concentration and diameter of soil hole.