Effect of Returning Agricultural Wastes on Tobacco-planting Soil Physical Properties and Root-knot Nematode Disease

In order to effectively control tobacco root-knot nematodes in tobacco plants, returning agricultural wastes (15 000 kg/ha) including rice shell, rice shell and chaff, tobacco stalks organic fertilizer, tea cake were studied on their effects on tobacco-planting soil physical properties and root-knot nematode disease in Xuan'en, Hubei province. The results showed that the physical properties of tobacco-planting soil could be improved in different degrees by increasing the content of soil water-stable aggregates more than 0.25 mm, soil total porosity, soil capillary water capacity and soil moisture, and reducing soil bulk density and soil capillary porosity. Agricultural wastes had a good effect on inhibiting the occurrence of tobacco root-knot nematode disease, with the control effect ranging from 23.86% to 84.50%, with rice shell and chaff showing the best control effect. Correlation analysis between soil physical properties and occurrence of tobacco root -knot nematode disease showed that the occurrence of tobacco root-knot nematodes had a significant negative correlation with soil total porosity and aeration porosity, and a significant positive correlation with soil bulk density. In summary, returning rice shell and chaff to the field can effectively improve the physical properties of tobacco-planting soil and control the root-knot nematodes.