Abstract: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.