Effects of different application rates of rice straw biochar and bamboo biochar on yield and quality of greengrocery(Brassica chinensis) and soil properties

Effects of two kinds of biochar at different application rates on yield and quality of greengrocery(Brassica chinensis) and soil properties were investigated for providing a scientific basis for the effective utilization of biochar on vegetable production. A field experiment was carried out in a farm with 0, 5, 10, 20 and 40 t/ha of rice straw biochar and bamboo biochar amendment under the condition of nitrogen fertilization. Yield and quality of greengrocery and soil properties were determined after the harvest. The results show that both rice straw biochar application and bamboo biochar application at high rates(20 and 40 t/ha) significantly reduce soil bulk density, and increase soil pH, organic carbon, total nitrogen and available K. However, soil available phosphorus and cation exchange capacity do not show significant differences between the treatments with and without biochar amendment. The yields of greengrocery are improved with biochar amendment. The vitamin C contents of greengrocery are increased, and total sugar contents are significantly increased by 31.2% and 19.5% while nitrate contents are significantly decreased by 15.0% and 16.4% under 40 t/ha of rice straw biochar and bamboo biochar amendment, respectively. The yield and quality of greengrocery and soil fertility can be improved by the application of rice straw biochar and bamboo biochar. Biochar can be applied to vegetables as a kind of soil conditioner. However, the suitable application amounts are determined by the types of biochar and vegetable.