EFFECTS OF DIFFERENT BIOCHAR FERTILIZATION MODELS ON RUNOFF AND SEDIMENT YIELD IN KARST YELLOW SOIL

Biochar is a carbon-rich solid substance produced by pyrolysis of biomass in anoxic or hypoxic environment, which has been an important application direction in agriculture in recent years. In this study, different concentrations of biochar were applied to the runoff plots of karst yellow soil, and the traditional farming and biochar fertilization methods were used for comparative experiments to analyze the effects of biochar on soil runoff and sediment reduction. The results showed that: 1. For runoff plot that have not taken any measures, the runoff yield and sediment yield were significantly positive correlated, R-2 =0.938, (P<0.01), and for runoff plots that have taken measures, the correlation between runoff yield and sediment yield was low, R-2 =0.048; 2. sediment retaining effects of different runoff plots were: runoff plot of surface covered with biochar > runoff plot of biochar + compound fertilizer> runoff plot of compound fertilizer> runoff plot of biochar> control plot, measures were taken to increase the sediment retaining rate of runoff plots entirely by 44.84% to 99.59% as well; runoff yield effects of different fertilization models were as follows: runoff plot of surface covered with biochar < runoff plot of biochar + compound fertilizer< runoff plot of compound fertilizer< runoff plot of biochar< control plot, and the range of runoff reduction in runoff plots where measures are taken was between 4.40% and 74.74%.