Distribution characteristics of phosphorus in topsoil of Jiangsu

Abstract：On the basis of relevant data from multi-target regional geochemical surveys in Jiangsu province, this paper presents the results of the latest study of the distribution of phosphorus in topsoil in the study areas and discusses the in-depth study of the results of the investigation and applied problems. The following has been preliminarily found: total phosphorus is of very uneven distribution in topsoil of the province and its content is very high on the surface; volcanic ash soil originating from basic rocks, fluvio-aquic soil and salinized soil are three major P-rich soil types in the province; the Olsen-P distribution is not completely controlled by total P and the Olsen-P concentration is >5 mg/kg in >85% of the topsoil in the province; the deficiency of Olsen-P is markedly superior to that of total P in topsoil. Data comparison indicates that: the land use pattern can directly affect the distribution of Olsen-P in topsoil; the Olsen-P content in the topsoil of grassland, shoals and forest is notably lower than that in others cultivated land; and regression analysis indicates that there is a pronounced positive correlation between total P and Olsen-P in topsoil samples from local places.