Effects of Organic Fertilizer Combined with Rice Husk Biochar on Soil Quality and Crop Productivity

As global warming accelerates, carbon sequestration in agricultural soils is essential for mitigating climate change.This study investigated the effects of organic fertilization with the 0%, 10%, and 30% (w/w) of rice husk biochar on soil quality and Chinese cabbage yield.The field-based experiments were conducted with four treatments, including non-organic fertilization and three mixing ratios of rice husk biochar in organic fertilizer.The combination of organic fertilizer and rice husk biochar at a 7:3 ratio improved the soil fertility, as indicated by increased available nitrogen (219.00 mg/kg) and phosphorus (404.77mg/kg) contents for crop plants.Additionally, carbon sequestration efficiency increased with higher biochar ratios in organic fertilizer, reaching 23.60 Mg C/ha in the 7:3 mixture of organic fertilizer and rice husk biochar.Although the crop yield decreased as the mixing ratio of biochar increased, the differences were not significant across treatments.This study found that combination of organic fertilizer and biochar improved soil carbon stock and nutrient availability, but crop yield was not varied by mixing ratio of biochar.For effective soil improvement, combining organic fertilizer and rice husk biochar at a ratio of 7:3 (w/w) is the optimal strategy.