Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 1, 2004
Publication Date: November 1, 2004
Citation: Eghball, B., Wienhold, B.J., Woodbury, B.L., Eigenberg, R.A. 2004. Plant availability of phosphorus in swine slurry and cattle feedlot manure. Agronomy Abstracts #3977. Technical Abstract: A laboratory incubation study was conducted to determine P mineralization and availability from applied swine and cattle feedlot manure in three soils. Treatments for each manure type included temperature (11, 18, 25, and 32 oC), water regime [constant 60% water filled pore space (WFPS), and variable which included four dry down cycles of 60% to 30% WFPS], time, and soils (Catlin silt loam, Sharpsburg silty clay loam, and Valentine fine sand). In another incubation study, synthetic P fertilizer was used to determine the quantity of P that becomes unavailable with time in the three soils. Constant water regime resulted in more P mineralization from cattle feedlot manure than variable soil water content at the P = 0.06 level. No significant effect of water regime was observed for the swine slurry. Water-soluble P followed a similar trend as soil test P during incubation. Phosphorus availability was 81 to 100 % of applied cattle manure P and 62 to 100% of swine slurry P in the three soils. Phosphorus availability was 100% of P in both manure types in the Sharpsburg soil. Phosphorus availability from manure is high and manure can be used similar to inorganic P fertilizer (100% available) in soils with adequate P or in areas susceptible to P loss in runoff. In P deficient soils, a P availability of 70% should be used.