Title: A Year Round Forage Production Manure Utilization System

Cooperators: G. Larry Newton, George Vellidis, Gary Gascho, J. C. Johnson, Jr., B.G. Mullinix, J.R. Allison, W.G. Hudson, III, R.K. Hubbard, R. Lowrance, R.N. Gates, A.W. Johnson, W.C. Johnson, III.

Problem:

Manure is recognized as a problem by our society. Dairy, livestock and poultry production has concentrated into units with greater animal numbers and, regardless of unit size, in localities with specialized infrastructure. This production, oftern on farms limited in acreage or suitability for extensive manure distribution, is potentially non-sustainable. Can an intensively managed, year round, manure irrigation-crop production system be economically and environmentally sustainable under production maximizing conditions?

Approach:

This research using liquid dairy manure or inorganic fertilizers is being conducted at both the plot and center pivot scales. Nutrient and water inputs, crops, soil and soil water are being sampled and monitored on both plots and under a center pivot in order to develop cropping, soil, and vadose zone portions of water and nutrient budgets. There are 12 replicated plots (10 m x 10 m) which are serviced by an array of irrigation sprinklers to apply liquid manure or inorganic fertilizers. One cropping system for the study is a mixture of Abruzzi rye and crimson clover overseeded in fall on a Tifton 44 bermudagrass sod (for spring haylage), minimum tillage silage corn seeded after rye/clover harvest, and bermudagrass hay harvest in summer. The other cropping system includes conventional minimum tillage with 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). Manure is applied to one half the plots, with applications every 7 to 21 days depending on rainfall and farming tasks. The remaining plots receive chemigated inorganic fertilizer and surface spread lime, based on soil test and Georgia Extension Service recommendations for each crop. Surface runoff, shallow groundwater, and deeper groundwater samples are being collected to monitor environmental impact.

Results

This is an ongoing research project and final results and conclusions are not available at this time.