Effects of Potato Straw Biochar on Soil Water Infiltration and Evaporation

【Objective】 The purpose of this study is to investigate the effect of biochar on soil water transport and nitrogen in the mountainous area of southern Ningxia. 【Methods】 Soil columns experiment was used to investigate the effects of potato straw biochar on typical soil water infiltration process, evaporation characteristics and nitrate leaching in southern Ningxia Mountains. There were six treatments with different active contents of carbon:0, 1%, 2%, 3%, 5% and 6%. 【Results】 The migration rate of wetting front and cumulative infiltration amount of mountain meadow soil was decreased after the biochar addition, dark loessial soil increased to a certain degree and then declined. Philip infiltration model was suiTable for the simulation of mountain meadow soil water infiltration process under biochar treatments, Kostiakov infiltration model was suiTable for the simulation of dark loessial soil water infiltration process under biochar treatments. During the successive evaporation of 33 days, biochar addition had significant effects on the cumulative evaporation in mountain meadow soil and dark loessial soil, there were extremely significant power function relationships between the cumulative evaporation and time under different rates of biochar treatments; The loss of nitrate nitrogen (NO^-₃-N) in the two soils showed a trend of first increasing, then decreasing and then strengthening with the increase of biochar addition, and the decrease was the smallest at 1% and the largest at 6%. 【Conclusion】 The application of potato biochar can improve the soil water holding capacity and reduce the loss of nitrate nitrogen.