Project Number: 6602-12630-001-00
Project Type: Appropriated

Start Date: Apr 03, 2005
End Date: Apr 02, 2010

Objective:
1. Determine the effects of conservation tillage, cover crops, and composted municipal sludge on soil quality and crop yield. 2. Determine the biomass production rates of grass, wetland, and horticultural species grown as floating vegetative mats in wastewater lagoons, and the value of this material as a soil amendment following composting. 3. Determine the effect of strip versus conventional tillage systems (receiving poultry litter or inorganic fertilizers as based upon soil test results) on N cycling and C accretion rates in Coastal Plain soils. Determine NO3-N and NH4-N concentrations in shallow seasonally perched groundwater from these systems. Determine the effectiveness of grass buffers, including buffer length and grass species in assimilating nutrients in surface runoff from poultry litter applied to cotton. 4. Determine mineralization rates of poultry litter in southeastern Coastal Plain soils.

Approach:
Field and laboratory studies will be conducted to determine if the use of conservation tillage, cover crops, and composted municipal sludge will improve soil quality (moisture retention, hydraulic conductivity, bulk density and C, N, P, and K levels) and crop quality and yield on a sandy coastal plain soil. Field studies will be conducted to determine whether grasses, wetland, or horticultural species can be found that will grow on floating platforms in the high ammonium, low oxygen wastewater of anaerobic animal wastewater lagoons; whether the biomass from these species can be harvested and composted to produce a soil amendment; and whether the nutrient content of soil amendments will be superior to composted land based plants grown under conventional fertility systems. Field studies will be used to determine the effect of strip versus conventional tillage systems (with and without poultry litter) and of grass species selection and buffer length on: N cycling, C accretion rates, and nutrient assimilation from surface runoff during cotton production. Field and laboratory studies will also be conducted in collaboration with the ARS mineralization group to determine the effects of soil type, moisture, and temperature on the potential mineralization rates of poultry litter in southeastern Coastal Plain soils.