Nitrogen Mineralization of Typical Tobacco-growing Soils in Guizhou Province

In order to investigate the organic nitrogen mineralization of tobacco-growing soils, three typical tobacco-growing soils: Yellow soil, Calcareous soil and Purple soil were chosen to measure the nitrogen mineralization by using the Stanford aerobic incubation method. The results indicated that the soil mineralization rate showed a tendency to decrease significantly, decrease gently and tend to be stable under aerobic condition. The average mineralization rate was Calcareous soil > Yellow soil > Purple soil. The accumulation of the soil mineralizable N increased slowly with the incubation time under aerobic condition. The tendency of the accumulation of the mineralizable N was similar with that of the soil mineralization rate. The accumulation of the mineralizable N increased rapidly from 0 to 63 days, accounting for about 78.42%~83.36% of the total accumulation of the mineralizable N. The accumulation of the mineralizable N was positively correlated with soil organic matter content. Prediction models of the accumulation of the mineralizable N in different typical tobacco-growing soils were also constructed by using soil mineralizable N content, organic matter content, and incubation time.