Effects of Poultry Litter Addition to a 31 Year Old Longleaf Pine Stand

Abstract

Nutrient depletion is a concern in longleaf (Pinus palustris) pinestands managed for pinestraw production in the Sandhills regions of the southeastern United States. The low-fertility soils associated with longleaf pine stands in the Sandhills region may not be able to sustain the repeated nutrient removal associated with pinestraw raking. Poultry litter, which is abundant in this region, may serve as a useful fertilizer amendment for offsetting nutrient removals. Nutrient cycling, water quality and productivity affects were examined under two poultry litter amendment regimes, a one time application of litter at 134 kg N ⁄ha (134 treatment) applied in the winter of 2000, and a two time application at the same rate applied in 1999 and 2000 resulting in a total application of 269 kg⁄ha (269 treatment).

Poultry litter addition significantly increased soil temperature, moisture, carbon (C) content, nitrogen (N) content, the effective cation exchange capacity (CECE), pH, base saturation, as well as the nitrate (N03- N) content in KCl extractable soil samples in the 269 treatment. The KCl extractable N in the surface 15 cm was greatest in the 269 treatment with a cumulative total of 56 kg N⁄ha of N reported versus 51 kg N⁄ha in the 0 treatment. Inorganic N enrichment occurred in soil solution measured at 15 and 60 cm deep in both treatments. At 15 cm, the N in solution ranged from 0.02 ppm (134 treatment) and 23.47 ppm (269 treatment). Vertical transport of N in solution was a major fate of the N measured at 15 cm, as solution N ranged from 0.20 ppm (0 treatment) and 33.82 ppm (269 treatment) at 60 cm. The increases in KCl extractable N and soil solution N concentrations following poultry litter application indicate that the litter was successful in enhancing N availability. Pinestraw production exhibited a significant increase of 17% in the 269 treatment as compared to the 0 treatment. Poultry litter is a viable soil amendment to longleaf stands managed for pinestraw production.