Nutrient Balance for Triple-crop Forage Production Systems Fertilized with Dairy Manure or Commercial Fertilizer

Thumbnail Image
Newton, G. Larry
Vellidis, George
Gates, R. N.
Hubbard, Robert K.
Lowrance, Richard
Johnson, A. W.
Hudson, W. G.
Sumner, H. R
Williams, R. G.
Allison, J. R.
Hatcher, Kathryn J.
Associated Organization(s)
Supplementary to
Three forage crops per year were grown on the same land to investigate production and environmental effects of manure fertilization. Crop sequences were com silage-bermudagrass hay-rye/clover haylage or com silagecom silage-rye/clover haylage. Both systems received each of two fertilizer sources; liquid dairy manure (600 kg of N/ha/year), and commercial fertilizer (recommended rates based on soil test). The cropping sequence including two crops of com silage has produced 26% greater forage dry matter than the system of one crop of com silage, and manure fertilization has produced 29% greater forage dry matter yields than commercial fertilizer application. For the first full cycle of crops, nitrogen recovery in crops for the com-bermuda-rye/clover system was 60.7% for manure and 54.4% for fertilizer while for the comcom- rye/clover system it was 55.3% for manure and 48.3% for fertilizer. There was a trend for increasing nitrate in the soil water at 0.8 meter depth under both cropping systems during early fall. This effect tended to be greatest for the system including bermudagrass and for commercial fertilizer application. For the manured treatments, an average of 33% of the phosphorus applied was removed in forage while for the fertilized treatments 205% of the amount applied was removed in forage. Phosphorus removal was similar for both cropping systems, but tended to be greater (on a kg/ha basis) for manure fertilization. This is a study-in-progress, but at the current time it appears that crop production (digestible dry matter yield) and nitrogen (recovery and movement) parameters may be somewhat superior for manure compared to commercial fertilization. The long term effects of applying more phosphorus than is removed may limit the sustainability of manure application at this and similar rates
Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of Technology
Date Issued
Resource Type
Resource Subtype
Rights Statement
Rights URI