|Newton, G - UNIVERSITY OF GEORGIA|
|Gascho, G - UNIVERSITY OF GEORGIA|
|Vellidis, G - UNIVERSITY OF GEORGIA|
|Hudson, Iii, W - UNIVERSITY OF GEORGIA|
Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: January 19, 1999
Publication Date: March 30, 1999
Citation: Newton, G.L., Gascho, G.J., Vellidis, G., Gates, R.N., Hubbard, R.K., Lowrance, R.R., Johnson, A.W., Hudson, III, W.G., Sumner, H.R., Williams, R.G. 1999. Nutrient balance for triple-crop forage production systems fertilized with dairy manure or commercial fertilizer. Georgia Water Resources Conf. 3/30-31, 1999, Athens, GA. Meeting Abstract Pp. 279-282. Interpretive Summary: Three forage crops/yr were grown on the same land to investigate production and environmental effects of manure fertilization.Crop sequences were corn silage-bermudagrass hay-rye/clover haylage or corn silage-corn 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 2 crops of corn silage has produced 26% greater forage dry matter than the system of one crop of corn 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 corn-bermuda-rye/clover system was 60.7% for manure and 54.4% for fertilizer while for the corn-corn-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 for manure fertilization. The long term effects of applying more phosphorus than is removed may limit the sustainability of manure application at this and similar rates.
Technical Abstract: Not required.