Effects Induced by Inputting Biochar into the Saliferous Gray Desert Soil on the Soil Moisture Movement

Objective To study the effect of biomass carbon input on soil moisture vertical movement in chloride-sulfate saliferous gray desert soil.MethodThe study materials were gray desert soil in three salinization levels which level 1 was low salinization,level 2 was medium salinization and level 3 was high salinization.Under different percentages of biochar inputs before and through the dropwise add of ddH2O,the time-varying of wetting front and accumulative infiltration capacity were calculated and analyzed.ResultThe vertical migration distance and the cumulative infiltration rate of wetting front were significantly increased(P < 0.05)with the infiltration time of different biomass carbon inputs in each degree of saline soil.The soil moisture movement in level 2 and level 3 saliferous soil were hindered by the biomass carbon;when the input percentage of biomass carbon was less than 4;to level 1 saliferous soil,the soil moisture movement could be facilitated by the biomass carbon;The relationship of biomass carbon input percentage with accumulative infiltration capacity in these three salinization soil were negatively correlated;there was no found in the relationship of biomass carbon inputs percentage with the accumulative infiltration capacity of vertical depth of wetting front in different salinization soil.ConclusionThe ratio of biomass carbon input,the degree of salinization and the interaction effect of the two have a significant impact on the infiltration efficiency and cumulative infiltration of soil water.The infiltration rate and infiltration amount to moderately saline soil were prominent.Low level input has a promoting effect on water transport in mildly saline soil and inhibitory effect on both cumulative infiltration rate and infiltration rate in severe saline soil.