Analysis On Nutrient Condition And Security Of Soil In The Tobacco Field Of Yaoan County

In order to evaluate the quality of soil and find the measure of soil improvement, the soils of tobacco production base in Yaoan county was analyzed, and the major results are as follows:1.1.In accordance with the relevant classification standards of soil fertility and the soil N supply capacity index of the high quality tobacco of China, the soil organic matter of paddy field and hilly field both achieve to the third level in Yaoan county,the difference is5.31g/kg. The average content of organic matter in production, should pay attention to use the quality of compost organic fertilizer after the full maturity.2. In accordance with the relevant classification standards of soil fertility and the high quality tobacco planting soil nutrient index of China, in soil of paddy field in Yaoan county total N achieves to the second level, available P achieves to the third level, available K achieves to the fourth level. In soil of hilly field total N achieves to the first level, available P achieves to the third level, available K achieves to the fourth level. Yaoan county available K content is extremely low, while total N is higher, the production should be strictly controlled in flue-cured tobacco nitrogen, and pay attention to the ratio of N、P、K fertilizer application, which can timely and quality of flue cured tobacco leaf yellowing.3. The heavy metal of the soil in tobacco production base was in the standard of "safety qualification of non—pollution tobacco", but in the Dahekou village of Guantun Base, the available Cd is beyond the standard achieves to0.334mg/kg, and in Yaoan Base, the available Cd is near to the critical level.4. In tobacco growth process,The average soil bulk desity of Yaoan county is between1.28～1.44g/m3, more suitable for the growing of tobacco roots, and suitable for the growth of tobacco plants,and the soil bulk desity is very heavy in the late stage of tobacco growth.5. In tobacco growth process,the soil pH of paddy field is between6.13-6.83,and the soil pH of hilly field is between5.2～45.90,while The soil pH of paddy field value reached6.83in the upper leaf harvest period, go beyond the most suitable pH for tobacco growth—5.5～6.5.and The upward trend evident.6. To improve the soil quality of Yaoan Base, the measures are as follows:fertilizing properly,regulating the soil physical condition properly, crop rotating properly, using green manure properly, paying more attention to cultivation and designing the field properly.