生物炭添加量对红壤坡耕地土壤水分运移的影响

华灿; 毛燕俊; 王妍鑫; 谢美娟; 何卫奇; 王洪; 舒晓庭; 陈正发

doi:10.19998/j.cnki.2095-1795.202511002

摘要: 为探究生物炭添加量对红壤坡耕地土壤水分运移的影响，开展不同浓度生物炭添加条件下红壤坡耕地土壤非饱和入渗试验。试验设置5个生物炭添加量梯度（0%、1%、3%、5%和10%），通过室内一维垂直定水头试验方法，分析土壤入渗过程湿润峰运移速率、入渗速率、累积入渗速率，以及入渗特征参数变化，并对其入渗过程进行拟合和适用性评价。结果表明，添加生物炭对湿润锋单位时间内的运移距离具有较强抑制作用，随生物炭添加量增加，湿润锋的运移距离逐渐降低。不同生物炭添加量处理下，红壤坡耕地的土壤入渗过程呈现一致的变化规律：初始阶段入渗速率较高，随入渗时间延长，入渗速率逐步减小并最终维持在稳定水平；累积入渗量随入渗时间的增加而提升，但提升幅度随生物炭添加量的增加而降低。不同生物炭添加量下，红壤坡耕地土壤入渗速率和累积入渗量呈现0%＞1%＞3%＞5%＞10%规律；土壤入渗特征参数均随生物炭添加量的增加而减小，稳定入渗速率较0%添加量处理分别减小8.5%、31.7%、34.1%和53.7%，平均入渗速率较0%添加量处理分别减小16.1%、29.4%、37.6%和55.6%。拟合结果表明，Horton、Green-Ampt和Philip模型3种入渗模型中，Horton模型拟合精度与效果优于其他2种模型。红壤坡耕地中添加生物炭可抑制土壤水分运移过程，并且抑制效果与生物炭添加量呈正相关关系，生物炭添加条件下红壤坡耕地土壤非饱和入渗过程可优先采用Horton模型进行拟合。

Abstract: To explore effects of biochar addition on soil water migration in red soil slope farmland, unsaturated infiltration experiment was carried out under different biochar addition conditions．Experiments were designed with five biochar addition gradients（0%, 1%, 3%, 5% and 10%）．By employing one-dimensional vertical constant head laboratory test, wetting peak migration rate, infiltration rate, cumulative infiltration rate, and infiltration characteristic parameters during soil infiltration process were analyzed, with infiltration process further fitted and evaluated for applicability．Results have indicated that biochar addition significantly inhibits migration distance of wetting front per unit time．As amount of biochar added increases, soil wetting front migration distance gradually decreases．Under different biochar addition treatments, soil infiltration process in red soil slope farmland exhibited a consistent pattern: infiltration rate was high in initial stage; as infiltration time increased, rate gradually decreased and eventually stabilized; while cumulative infiltration amount gradually increased with advance of infiltration time, but increase range decreased as biochar application rate increased．Soil infiltration rates and cumulative infiltration volumes of red soil slope farmland under different biochar addition treatments follow pattern: 0% > 1% > 3% > 5% > 10%．All soil infiltration parameters decreased with increasing biochar addition．Stable infiltration rates decreased by 8.5%, 31.7%, 34.1%, and 53.7%, respectively, compared to the 0% addition treatment, while average infiltration rates decreased by 16.1%, 29.4%, 37.6%, and 55.6%, respectively．Fitting results have indicated that among three infiltration models of Horton model, Green-Ampt model, and Philip model, Horton model demonstrated superior fitting accuracy and performance compared to the other two models．Biochar addition to red soil slope farmland significant inhibited soil water migration processes, and inhibitory effect was positively correlated with biochar addition．Under biochar-amended conditions, Horton model can be prioritized for fitting unsaturated infiltration processes in red soil slope farmland．

生物炭添加量对红壤坡耕地土壤水分运移的影响

Effects of biochar addition on soil water migration in red soil slope farmland