生物炭-土壤结皮对土壤水分入渗和蒸发特征的影响

Effects of biochar-soil crust on soil water infiltration and evaporation

为提高降水资源利用效率和选择适宜生物炭覆盖量,采用垂直一维定水头入渗法,研究土壤结皮(生物炭覆盖量为0×104 kg/hm 2)、单倍炭-土壤结皮(生物炭覆盖量为3×104 kg/hm 2)和双倍炭-土壤结皮(生物炭覆盖量为6×104 kg/hm 2)对土壤入渗和蒸发特征的影响。结果表明:生物炭-土壤结皮的累计入渗量、初始入渗速率、稳定入渗速率和平均入渗速率随生物炭覆盖量增加而增加,与土壤结皮相比,单倍炭-土壤结皮的累计入渗量、初始入渗速率、稳定入渗速率和平均入渗速率分别增加16.9%、30.8%、2.6%和16.9%,双倍炭-土壤结皮分别增加32.1%、59.5%、3.7%和32.1%。经过3种模型(Philip、Kostiakov和Horton)模拟精度比较,Horton入渗模型适用于生物炭-土壤结皮的土壤水分入渗特征的模拟。生物炭-土壤结皮的累计蒸发量随生物炭覆盖量增加而减少,与土壤结皮相比,单倍炭-土壤结皮和双倍炭-土壤结皮的0~60 d累计蒸发量分别减少7.4%和12.3%。生物炭-土壤结皮的研究将关注于持水力、疏水性等方面研究。

To increase rainwater?use efficiency and find a suitable biochar application rate,effects of biochar-soil crust on soil water infiltration and evaporation were studied by one-dimensional vertical infiltration of water.The treatments included soil crust(with biochar application rate at 0×104 kg/ha),single biochar-soil crust(with biochar application rate at 3×104 kg/ha)and double biochar-soil crust(with biochar application rate at 6×104 kg/ha)with three replications.Cumulative infiltration,initial soil infiltration rate,stable infiltration rate,mean soil infiltration rate increased as biochar application rate increased.Compared with soil crust,the cumulative infiltration,initial soil infiltration rate,stable infiltration rate and average soil infiltration rate increased by 16.9%,30.8%,2.6%and 16.9%,respectively,for single biochar-soil crust,and by 32.1%,59.5%,3.7%,and 32.1%,respectively,for double biochar-soil crust.The performance of the Horton model was applicable to the infiltration estimation of biochar-soil crust after comparing the coefficients of simulation accuracy among three models.Biochar-soil crust decreased soil evaporation.Compared with soil crust,cumulative evaporation decreased by 7.4%and 12.3%,respectively,for single biochar-soil crust and double biochar-soil crust.The effects of biochar-soil crust on soil water retention and soil water repellency warrants further study in future.