Phosphorus Losses in Leachate from Three Agricultural Soils as affected by Varying Fertilizer Application Methods and Soil Wetting and Drying Cycles

Abstract

Eutrophication has been identified as a major environmental concern for freshwater aquatic ecosystem health. As climate and agricultural management practices change, changes in prominent water flow pathways and risk of P loss are expected. This study was conducted to evaluate variations in P losses, specifically DRP and TP, across MAP Fertilizer and wetting and drying cycles (WDC). Intact soil cores of different soil textures (clay, sandy loam and sand) were subjected to 12 rainfall events to generate leachate. Results from cumulative losses of DRP and TP tended to mask treatment effects; however, individual leaching events treatment differences were identified, notably the significant interaction between MAP placement and WDC which across all soils. Soils analysis by depth following all rainfall events did not conclusively indicate evidence of fertilizer P movement. Results suggest that management strategies to minimize P leaching are dependent upon soil conditions and the first leaching event.