Field-scale evaluation of phosphorus leaching in acid sandy soils receiving swine waste

J Environ Qual. 2005 Oct 12;34(6):2024-35. doi: 10.2134/jeq2004.0445. Print 2005 Nov-Dec.

Abstract

Accurate descriptions of P leaching are important because excess P applied to soils can enter surface water via leaching and subsurface transport, thereby negatively impacting water quality. The objectives of this study were to monitor P leaching in soils with a long-term history of waste application, relate soil solution P concentrations to soil P status, and quantify P leaching losses. Soil solution was monitored for 20 mo with samplers installed at 45-, 90-, and 135-cm depths in two pits (1 x 3 x 1.5 m) in Autryville (loamy, siliceous, thermic Arenic Paleudults) and Blanton (loamy, siliceous, semiactive, thermic Grossarenic Paleudults) soils located in a grazed pasture in Sampson County, NC, which had received swine waste for >20 yr. Maximum soil solution P concentrations at 45 cm exceeded 18 mg L(-1) in both soils. Soil solution P concentrations at 90 cm in the Blanton soil were similar to that at 45 cm indicating low P sorption. Soil solution P concentrations at 90 cm in the Autryville soil averaged 0.05 mg L(-1) compared to 10 mg L(-1) at 45 cm. A split-line model related soil solution P concentration to the degree of phosphorus saturation (DPS), identifying a change point at 45% DPS. Phosphorus movement past 45 cm equaled or exceeded surplus P additions for both soils. Long-term waste applications resulted in DPS > 90%, high soil solution P concentrations, and substantial vertical P movement. Phosphorus leaching should be considered when assessing long-term risk of P loss from waste-amended soils.

MeSH terms

  • Animal Husbandry / methods
  • Animals
  • Manure
  • Phosphorus / metabolism*
  • Soil Pollutants / metabolism
  • Soil*
  • Swine*

Substances

  • Manure
  • Soil
  • Soil Pollutants
  • Phosphorus