肥液浓度和生物质掺混量对微润灌溉入渗特性的影响

为了探明肥液质量浓度和生物质掺混质量比对微润灌溉土壤水分入渗特性的影响,采用室内土箱模拟试验的方法,设置3个肥液质量浓度水平(清水F₀:0 mg/L,低浓度F_L:200 mg/L,高浓度F_H:400 mg/L)和4个生物质掺混质量比水平(自然风干土B₀:0 g/kg,低掺混量B_L:15 g/kg,中掺混量B_M:30 g/kg,高掺混量B_H:45 g/kg),以发酵腐熟花生壳粉末为掺混生物质,研究微润灌溉的水分入渗速率、累积入渗量、湿润体体积以及湿润体质量含水率的分布特征.试验结果表明:肥液质量浓度和生物质掺混质量比对微润灌溉的初始入渗速率、稳定入渗速率、累积入渗量和湿润体质量含水率均值影响均具有统计学意义.与水平F₀B₀相比,增加肥液质量浓度和生物质掺混质量比可提高初始入渗速率13.02%~44.85%、稳定入渗速率13.50%~48.78%、累积入渗量5.65%~56.62%和湿润体质量含水率均值6.62%~30.09%;不同入渗时间内的累积入渗量符合Kostiakov模型;湿润体体积随肥液质量浓度和生物质掺混质量比增大而增大,且湿润体体积与入渗时间呈二次多项式关系;湿润体剖面面积和灌水均匀系数随肥液质量浓度和生物质掺混质量比增大而增大.

Effects of fertilizer solution concentration and biomass content on infiltration characteristic of moistube irrigation

In order to identify effects of fertilizer solution concentration and biomass content on soil water infiltration characteristics in moistube irrigation where fermented peanut shell power was used as mixed biomass, a series of indoor soil box simulation experiments were performed. In the experiments, the fertilizer solution concentration was at three levels(F₀-pure water: 0 mg/L, F_L- low concentration: 200 mg/L, F_H-high concentration: 400 mg/L), the mixed biomass content was at four levels(B₀-natural air-dry soil: 0 g/kg, B_L-low mixed content: 15 g/kg, B_M-moderate mixed content: 30 g/kg, B_H-high mixed content: 45 g/kg), and infiltration rate, cumulative infiltration, wetted soil volume and distribution characteristics of soil moisture were examined. The results indicate that the fertilizer solution concentration and mixed biomass content have a statistically significant effect on the initial infiltration rate, steady infiltration rate, cumulative infiltration and average content of soil moisture. Compared with the control treatment F₀B₀, increasing fertilizer solution concentration and biomass content has improved the initial infiltration rate by 13.02%-44.85%, the steady infiltration rate by 13.50%-48.78%, the cumulative infiltration by 5.65%-56.62% and the average content of soil moisture by 6.62%-30.09%, respectively. The cumulative infiltration in terms of time is accorded with Kostiakov model. The wetted soil volume increases with increasing fertilizer solution concentration and biomass content, and can be fitted with a quadratic polynomial of infiltration time. The cross-sectional area of wetted soil and the uniformity coefficient of moistube irrigation increase with increasing fertilizer solution concentration and biomass content. 