Seasonal Changes in Available Phosphorus and Different Enzyme Activities in Arid Soil

Abstract

Available P and phosphatases and dehydrogenase activities associated with Arid soil were assessed over a 12 month period under crops, grass, trees and fallow land. There were considerable seasonal fluctuations. Generally, maximum enzyme activities as well as available P status were observed during the rainy season in all the soils, while the activities of dehydrogenase and phosphatases and the amount of available P were at minimum during summer months. The soils under crops and trees had significantly higher activities of dehydrogenase and phosphatases and available P than those observed under grass and fallow. Surface soil (0-15 cm) had significantly higher available P and enzyme activities compared to sub-surface soil (15-30 cm). The results indicated that enzyme activities and available P status in the soil are dependent upon vegetation, temperature and moisture.