Influence of Biochar on Water Retention Capacity and Nitrogen and Potassium Loss of the Vegetation Substrate Based on Yellow River Sediment

The ecological restoration of the Yellow River Basin faces dual challenges of soil deficiency and water scarcity,further complicated by sediment accumulation.This study investigated the influence of three wood biochar application rates (0,1%,and 2%) on the water holding capacity,infiltration characteristics,and nitrogen and potassium losses of the vegetation substrate formulated from Yellow River sediment.The results indicate that the addition of biochar effectively enhances porosity,field water capacity,and saturated water content,while concurrently reducing stable infiltration rates,cumulative infiltration volumes,and saturated hydraulic conductivity of the vegetation substrate based on Yellow River sediment.There is an extremely significant negative correlation between biochar content and both the average loss rate and proportion of ammonium nitrogen and available potassium of the substrate (P<0.01).Taking into account both ecological restoration functions and economic costs,it is concluded that a biochar content of 1% can effectively enhance the water retention and nutrient retention capabilities of the vegetation substrate based on Yellow River sediment.