Seasonal Phosphorus Losses in Runoff from a Coastal Plain Soil

Abstract

Nutrients from agricultural fields can contaminate runoff and groundwater and enhance eutrophication. Runoff, soil loss, soluble P (SP), and bioavailable P (BP) associated with runoff and soil loss were measured from six 2 h simulated rainfall events (1 in./h) to determine amount of P transported during a corn (Zea mays L.) growing season and to develop relationships that predict P amounts and forms leaving different size field plots. Two 60-sq-ft microplots and two 6500-sq-ft mesoplots (3% slope) were located on a Tifton loamy sand (fine-loamy, siliceous, thermic Plinthic Kandiudult). Phosphorus was broadcast at 31 Ib P/acre, then incorporated to a depth of 6 in. Corn (conventional tillage) was planted after fertilizer application. Six simulated rainfall events occurred 5 d before and 1, 14, 29, 49, and 108 d after fertilizer application [...]