Submitted to: Journal of Dairy Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/5/2003
Publication Date: 6/20/2003
Citation: NEWTON, G.L., BERNARD, J.K., HUBBARD, R.K., ALLISON, J.R., LOWRANCE, R.R., GASCHO, G.J., GATES, R.N., VELLIDIS, G. MANAGING MANURE NUTRIENTS THROUGH MULTI-CROP FORAGE PRODUCTION. JOURNAL OF DAIRY SCIENCE. 86(6):2243-2252. 2003. Interpretive Summary: Concentrated sources of dairy manure represent significant water pollution potential. The Southern US may be more vulnerable to water quality problems than some other regions because of climate, land available on animal production farms, and cropping practices. Dairies require large amounts of high quality forage. It is more difficult to produce high quality forages in the South because of climatic effects on the selection of forages and direct effects on plants. Dairy manure can be an effective source of plant nutrients and large quantities of nutrients can be recycled through forage production, especially when multi-cropping is practiced. Such systems can produce acceptable to high quality forage, protect the environment, and be economically attractive. An optimum manure-forage system will depend on the farm characteristics, and specific local conditions. Buffers and nutrient sinks can protect streams and water bodies from migrating nutrients and should be included as part of crop production systems. Research was conducted at Tifton GA using dairy lagoon wastewater as a nutrient for multi-crop forage production. Two systems were investigated: a mixture of Abruzzi rye and crimson clover overseeded in fall into a Tifton 44 bermudagrass sod, minimum tillage silage corn seeded after rye/clover harvest, and bermudagrass hay harvested in summer (CBR); and conventional minimum tillage rye and clover established in fall, a first crop of temperate corn in spring and a second crop of tropical corn in summer (both for silage) (CCR).. The management practices as implemented were proven to be economically profitable. Manure application resulted in lower nematode and soil borne fungal disease pressure compared to commercial fertilizer, possibly contributing to an 8% yield advantage for manure compared to fertilizer. This research is important to animal producers and land managers because it provides information which will assist them in utilizing animal wastes while reducing the risk of environmental contamination.
Technical Abstract: Contamination of soils, surface waters, and ground waters from animal wastes is an environmental concern. Intensive animal operations can result in high nitrogen (N) or phosphorus (P) loading rates to soils and waters. Land treatment of systems for animal wastes may include application of wastewater to crops, pasture , or vegetated buffer systems. Research at Tifton GA has investigated the utilization of dairy manure on a frequent year round basis in an attempt to reduce manure storage and its associated cost and potential for nutrient loss, odor and overflow; to maximize recycling of nutrients in crops; and reduce labor demands associated with seasonal manure application. Forage systems were selected to allow the maintenance of vegetative plants on the soil on an essentially continuous basis. The two systems investigated were a mixture of Abruzzi rye and crimson clover overseeded in fall into a Tifton 44 bermudagrass sod, minimum tillage silage corn seeded after rye/clover harvest, and bermudagrass hay harvest in summer (CBR); and conventional minimum tillage (no living cover crop) rye and clover established in fall (for haylage), a first crop of temperate corn in spring and a second crop of tropical corn in summer (both for silage) (CCR). These systems were investigated at field scale under a pivot irrigation system and in replicated small plots, and included comparisons between manure and commercial fertilizer which was applied at rates based on soil test. With liquid dairy manure as the only nutrient source, DM yields over 4 yr averaged 29.3 and 32.5 tonne/ha for the CBR and CCR systems respectively. The system including the deep rooted perennial cover crop - bermudgrass - recovered a higher proportion of the applied N. Manure application resulted in lower nematode and soil borne fungal disease pressure compared to commercial fertilizer, possibly contributing to an 8% yield advantage for manure compared to fertilizer.