Effects of Anaerobic Disinfection on Properties in Tobacco-planting Soil, Yield and Quality of Flue-cured Tobacco

Abstract

【Objective】The impact of anaerobic disinfection (ASD) on the properties of tobacco field soil, major soil-borne diseases of tobacco, and their yield and quality is investigated by employing effective and pollution-free soil improvement techniques through the application of different organic materials.【Method】The field experiment wasconducted in two tobacco production areas in Dapu and Nanxiong, Guangdong Province. Three treatment groups of rice bran (MK), wood chips (MX) and rice bran mixed with wood chips (KX) were set up for soil anaerobic disinfection (ASD), and that without the addition of organic materials was used as CK, then soil properties, occurrence of major diseases and economic traits of tobacco were analyzed between different treatments.【Result】The results showed that ASD treatments with organic materials significantly increased soil pH value, soil enzyme activity and soil nutrient content in two production areas when compared with CK, while reduced soil EC value. In the Dapu production area, the mass fractions of soil organic matter, total nitrogen, available nitrogen, available phosphorus, and available potassium increased by 29.0%-40.6%, 7.0%-24.2%, 18.0%-24.4%, 25.9%-43.0%, and 37.5%-81.7%, respectively, compared to the control group (CK). The incidence rates of tobacco blue mold and black shank disease decreased by 5.8-17.3 and 7.5-15.8 percentage points, respectively, compared to CK. The disease severity index decreased by 34.7%-69.0% and 30.4%~68.9%, respectively, compared to CK. In the Nanxiong production area, the mass fractions of soil organic matter, total nitrogen, available nitrogen, available phosphorus, and available potassium increased by 0.1%-35.2%, 55.8%-89.4%, 19.7%-30.0%, 22.2%-27.5%, and 34.0%-76.3%, respectively, compared to CK. The incidence rates of tobacco blue mold and black shank disease decreased by 5.6-12.6 and 11.7-18.0 percentage points, respectively, compared to CK. The disease severity index decreased by 16.1%-63.7% and 43.4%-64.3%, respectively, compared to CK. In both production areas, the average tobacco yield per hectare increased by at least 1 949.25 yuan compared to CK. The proportion of high-grade tobacco in Dapu and Nanxiong production areas increased by 1.2~4.2 and 0.7-2.9 percentage points, respectively, compared to CK. The results of redundancy analysis showed that the incidence of bacterial wilt and black shank of flue-cured tobacco in Dapu was greatly affected by sucrase activity, and the incidence of flue-cured tobacco in Nanxiong was greatly affected by urease activity.【Conclusion】Adding MK (10 t/hm2) for ASD treatment in tobacco fields with frequent continuous cropping and severe soil-borne diseases. This treatment can effectively improve soil characteristics and enhance the quality of tobacco production.

Keywords

• flue-cured tobacco
• anaerobic soil disinfestation (asd)
• soil quality
• bacterial wilt
• black shank