Effect of Copper Levels in Swine Manure on Corn and Soil1
- A. L. Sutton,
- D. W. Nelson,
- V. B. Mayrose and
- D. T. Kelly2
Effects of Cu levels in liquid swine manure were studied for 5 y on corn (Zea mays L.) and Crosby silt loam soil (Aerie Ochraqualfs). Pigs housed on slatted floors above pits were fed 16% crude protein corn-soy diets with either 0, 125, or 250 mg/kg of supplemental Cu as CuSO4. Swine manure (3.2–5.2% dry matter) collected from the anaerobic pits was surface-applied annually to soil at rates of 90, 180, and 270 t/ha for 4 y. No manure was applied the fifth year to determine the effects of residual nutrients. Check and inorganic fertilizer (168 kg N/ha, 56 kg P/ha, 112 kg K/ha) treatments were also included.
Supplemental CuSO4 in the swine diet increased Cu levels in manure and consequent Cu application to the soil. Copper-enriched manure increased the 1N HCl-extractable Cu in the upper portion of the soil profile (0–31 cm), but not at lower depths. High Cu applications from manure did not elevate plant leaf Cu concentrations, and did not adversely affect corn yields.
Corn yields and leaf composition were not affected by rate of manure application since crop nutrient requirements were exceeded. Applied K and NO3−-N moved downward in the soil profile, but a majority of these nutrients in soil were depleted by the end of the study. In contrast, applied P accumulated in the upper soil profile (0–31 cm).
Application of liquid swine manure from pigs fed a high level of CuSO4 over a 4-y period at the rates used in this study did not lead to excessive soil accumulation or enrichment of corn tissue with Cu.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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