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Water Quality Impacts of Converting to a Poultry Litter Fertilization Strategy
Author(s) -
Harmel R. D.,
Torbert H. A.,
Haggard B. E.,
Haney R.,
Dozier M.
Publication year - 2004
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2004.2229
Subject(s) - surface runoff , environmental science , litter , poultry litter , pasture , water quality , nutrient , agronomy , fertilizer , hydrology (agriculture) , zoology , watershed , ecology , biology , geotechnical engineering , engineering , machine learning , computer science
When improperly managed, land application of animal manures can harm the environment; however, limited watershed‐scale runoff water quality data are available to research and address this issue. The water quality impacts of conversion to poultry litter fertilization on cultivated and pasture watersheds in the Texas Blackland Prairie were evaluated in this three‐year study. Edge‐of‐field N and P concentrations and loads in surface runoff from new litter application sites were compared with losses under inorganic fertilization. The impact on downstream nutrient loss was also examined. In the fallow year with no fertilizer application, nutrient losses averaged 3 kg N ha −1 and 0.9 kg P ha −1 for the cultivated watersheds and were below 0.1 kg ha −1 for the pasture watersheds. Following litter application, PO 4 –P concentrations in runoff were positively correlated to litter application rate and Mehlich‐3 soil P levels. Following litter application, NO 3 –N and NH 4 –N concentrations in runoff were typically greater from cultivated watersheds, but PO 4 –P concentrations were greater for the pasture watersheds. Total N and P loads from the pasture watersheds (0.2 kg N ha −1 and 0.7 kg P ha −1 ) were significantly lower than from the cultivated watersheds (32 kg N ha −1 and 5 kg P ha −1 ) partly due to lower runoff volumes from the pasture watersheds. Downstream N and P concentrations and per‐area loads were much lower than from edge‐of‐field watersheds. Results demonstrate that a properly managed annual litter application (4.5 Mg ha −1 or less depending on litter N and P content) with supplemental N should supply necessary nutrients without detrimental water quality impacts.