Environmental risks of increasing phosphorus addition in relation to soil sorption capacity

Phosphorus content of soil profiles, interstitial water, and shallow groundwater was determined in a semiurban region of Buenos Aires city in order to examine phosphorus leaching. Soils from different places and position in the slope were characterized and analysed for their P sorption–desorption capacities in order to understand transport processes and to assess potential environmental risks. Adsorption increases with depth and decreases with increasing additions of phosphorous. Interstitial water at 0.6 m depth showed greater P concentrations than shallow groundwater (9 to 30 m depth) in accordance with the importance of clays for P adsorption.