Abstract:

To determine the feasibility of the substitution of organic fertilizer for chemical fertilizer in flue-cured tobacco production and the optimized proportions of chemical fertilizer reduction, we compared the effects of different amounts of organic fertilizer as the substitution for chemical fertilizer on the yield and quality of flue-cured tobacco as well as the physical and chemical properties and enzyme activities of soil. The results showed that: (1) the organic fertilizer substitution for 15% N chemical fertilizer treatment was superior to the control treatment in plant height, maximum leaf length, maximum leaf width, effective leaf number and stem circumference; (2) the yield, output value, mid-high grade tobacco, high grade tobacco and average price of tobacco in the organic fertilizer substitution for 15% N chemical fertilizer treatment were higher than those of the control treatment, especially the proportion of high grade tobacco was 78.18% higher; (3) the chemical constituents of middle leaves were all coordinated, and the organic substitution treatment was better than the control treatment; (4) compared with the control treatment, the organic fertilizer substitution for 15% N chemical fertilizer treatment increased soil available P, total N, total K and available Si content, notably, the available Si content increased significantly by 55.47%; the organic fertilizer substitution for 15% N chemical fertilizer treatment also increased soil invertase, urease, dehydrogenase activity. In conclusion, the organic fertilizer substitution for 15% N chemical fertilizer treatment has the best effect for improving the yield of flue-cured tobacco and soil fertility.

Key words: reducing chemical fertilizer, organic fertilizer substitution, flue-cured tobacco, yield and quality