Abstract:

The effects of different previous crops on soil nutrients were compared in Chuxiong to screen suitable previous crops for tobacco. It was of great significance to guide the production of flue-cured tobacco. The results showed that the pH of some soil in winter fallow field and after barley planting was much higher, and the content of available nitrogen was much lower. So it was necessary to improve the soil pH and increase the amount of organic matter when planting flue-cured tobacco. After planting broad beans, 33.33% of the soil pH was higher, and the content of organic matter in some soil was in a very deficient level, and the content of organic carbon was low. After wheat planting, more than 98% of the soil pH was suitable for tobacco planting, and the content of soil organic matter, organic carbon and available potassium was the highest. The soil fertility was suitable for subsequent tobacco planting. After planting rape, the soil organic matter and organic carbon content were rich, the content of available potassium and available nitrogen and fertility was moderate. In all, wheat was suitable previous crop for flue-cured tobacco, followed by rape. After planting broad beans, soil pH needed to be improved. Winter fallow fields and after planting barley, attention should be paid to adjusting pH and increasing organic matter.

Key words: previous crops, tobacco planting soil, soil acidity and alkalinity, soil nutrient, grade of nutrient