Control Effect of Biochar-based Fertilizer on Chinese Cabbage Follow-up Tobacco Soil-borne Diseases and Its Mechanism

Abstract：The previous investigations found that the Chinese cabbage follow-up tobacco soil was poor,re-sulting in worse botany characters and more serious root diseases. In order to explore method for follow-up tobacco soil health remediation,the field trial was carried out to assess the control effect of biochar-based fertilizers on soil-borne diseases of follow-up tobacco and to analyze its mechanism. The result showed that application of biochar could significantly decrease the incidence and disease indexes of tobacco root-knot nematode,black shank and black root rot(P<0. 01). The relative control effect on the three diseases of the liquid biochar(M-20,300 kg/ha) was 74. 23%—78. 26%,and that of the mixture of solid biochar (EC-40,300 kg/ha)with liquid biochar(M-20,300 kg/ha) was 77. 32%—86. 36%. Both of the two bio-char-based fertilizer treatments could improve the plant height,number of productive leaves,and the big-gest leaf area. Meanwhile,the mixture was better than the liquid biochar. Microecological analysis of the soil samples indicated that the biochar could effectively increase bacterial number,organic matter content, activities of soil invertase,amylase and cellulase. In general,application of biochar on Chinese cabbage follow-up tobacco could quickly remediate soil health,improve plant development and effectively controltobacco soil-borne diseases,which is a practical method with great potential.