ARS | Publication request: THE SUITABILITY OF SOIL TEST PHOSPHORUS FOR PRIORITIZING FIELDS RECEIVING MANURE

Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: June 21, 1999
Publication Date: October 1, 1999
Citation: LORY, J.A., SCHARF, P.C., JOERN, B.C., POTE, D.H. 1999. THE SUITABILITY OF SOIL TEST PHOSPHORUS FOR PRIORITIZING FIELDS RECEIVING MANURE. SOIL SCIENCE SOCIETY OF AMERICA ANNUAL MEETING. p. 292.

Technical Abstract: Soil testing has traditionally focused on identifying fields where phosphorus (P) is a limiting nutrient for crop production. Recent concerns about the effects of runoff P on water quality have led to the successful use of soil test P (STP) to identify fields with high potential for P runoff. This has spurred interest in using STP thresholds as the sole or a partial criteria for limiting manure applications. We reviewed relationships reported in the literature between P applications (manure or fertilizer), STP, and runoff P to evaluate the hypothesis that moving manure applications from fields with high STP to soils with lower STP will improve water quality (reduce P in runoff) within a watershed. Our review suggests that such strategies may not be effective for soils containing up to 400 mg kg-1 Bray-I or Mehlich III P, except on some very low testing soils. This result emphasizes the importance of runoff potential as the core component for making manure application decisions on these soils. Additional research is needed at STP levels above 400 mg kg-1 Bray-I or Mehlich III P and to evaluate the effects of STP on the equilibration rate of applied P with the soil.