Abstract:To explore the effects of biochar on soil and water conservation in slopping farmland of black soil region, the experiments for the influences of different amounts of biochar supply (0t/hm2,25t/hm2,50t/hm2,75t/hm2 and 100t/hm2) on soil structure, water holding property, runoff and sediment control, etc. were conducted in the runoff plots, which were located at the slopping farmland with three degrees of terrain slope in Hongxing state farm of Beian City, Heilongjiang Province in the typical black soil belt. The results showed that the biochar could effectively improve the soil structure in black soil region, and the soil bulk density was decreased with the increase of amount of biochar, but the soil porosity was just opposite. And some indexes for indicating the soil water holding capacity, such as saturated soil water content, field water capacity and soil water storage were all increased with the increase of biochar supply amount. The runoff and soil erosion in slopping farmland could also be controlled by suitable supply of biochar, the best treatment for run-off and sediments control was that with 75t/hm2, and the effect of runoff control was better than that of the sediment control. Biochar supply also could reduce the soil nutrient loss and improve the spacial distribution of soil nutrient at different degrees, and the soil nutrient contents for the four treatments of biochar supply were all higher than that without biochar supply, and the evenness degree of soil nutrients distribution was also improved obviously, which made the differences of soil nutrients between upslope and downslope reduced. The results could provide a new way for efficient, green and recycling utilization of straw resource in the northeast black soil region, the theoretical foundation for prevention and control of water and soil erosion in slopping farmland of black soil region, which have important significance to promote the regional sustainable development of agriculture.
