Water-Quality effects of infiltration rate and manure application rate for soils receiving swine manure

Abstract

We investigated the effects of rain infiltration rate and manure application rate on the quality of leachate and runoff from four soils. Tall fescue (Festuca arundinacea Schreber) plots received swine (Sus scrofa L) manure slurry at 1 or 2 Mg (dry weight) ha -1 to provide N at 78.4 or 156.8 kg ha -1 . Simulated rain (75 mm hr -1 ) applied 24 hr after slurry application produced 30 min of runoff from each plot. Mean infiltration rates ranged from 7.7 to 60.6 mm hr -1 . Concentrations and mass losses of total Kjeldahl nitrogen (TKN), NH 4 -N, dissolved reactive P (DRP), and total P in runoff increased significantly (α = 0.05) following slurry applications, and doubled when slurry application doubled. High infiltration rates reduced runoff volumes and runoff concentrations of Cl, total dissolved solids, DRP, TKN, and NH 4 -N. Concentrations of NO 3 -N and NH 4 -N in leachate water, collected at 0.4 m depth by suction cup lysimeters, did not increase following slurry applications.