Abstract
Increases in number and size of dairy and poultry enterprises in Texas have contributed to concerns about potential hazards of waste management schemes to surface and groundwater quality. Results from two years of dairy effluent and poultry litter applications to bermudagrass (Cynodon dactylon) and ryegrass (Lolium multiflorum Lam) sods were used to quantify N03 leaching below the root zone of a Darco loamy fine sand (loamy, siliceous, thermic Grossarenic Paleudult) located at Overton, Texas. Rates of 0, 250, 500, and 1000 kg N ha-1 were spread in four equally split applications of dairy effluent or poultry litter. Nutrient analyses of soils and harvested biomass were used in monitoring fate of applied N, P, and K. Mean N03 content of leachates collected from porous ceramic-cup lysimeters were used to quantify N leaching. Results from leachate analysis indicated significant N03 loss from plots receiving either form of animal waste at 1000 kg N ha-1. At rates delivering equivalent quantities of N to soil, poultry litter had a greater impact on N03 and P leaching than did dairy effluent. Soil tests indicated some P leaching down to the 90-120 cm depth resulting from the high rate of P from poultry litter. This information has contributed to improvements in animal waste management systems.
Johnson, Andrew Floyd (1995). Forage, soil and water quality responses to animal waste application. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1995 -THESIS -J634.