ARS | Publication request: Effects of broiler litter and nitrogen fertilization on uptake of major nutrients by coastal bermudagrass

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 4, 2006
Publication Date: April 1, 2006
Citation: Read, J.J., Brink, G.E., Oldham, J.L., Kingery, W.L., Sistani, K.R. 2006. Effects of broiler litter and nitrogen fertilization on uptake of major nutrients by coastal bermudagrass. Agronomy Journal. 98:1065-1072.

Interpretive Summary: Broiler litter (a mixture of chicken manure, wasted feed, and bedding materials) is commonly used as fertilizer for Coastal bermudagrass, an important forage crop in the Southeast USA. Agronomists and soil scientists conducted studies at two locations in Mississippi to determine if replacing the organic nitrogen (N) in litter with inorganic N fertilizer (ammonium nitrate) is an effective method to increase the annual uptake of N and phosphorus (P) by bermudagrass. Because potential losses of N and P to the environment may decrease water quality, a fertilizer combination was sought that would maximize plant productivity, and thereby, the uptake of these nutrient elements. The treatments were five rates of litter combined with five rates of inorganic fertilizer so that each treatment provided the annual N requirement of bermudagrass hay, about 240 pounds N/acre. Results from a location with a long history of litter application suggest a best management practice is to provide half the N requirement of bermudagrass with litter (about 2 tons/acre) in the spring and the remainder with inorganic N fertilizer. Results from a location with no history of litter application suggest yield and uptake of N and P were maximized when bermudagrass was provided a combination of 4 tons of broiler litter and 120 pounds of inorganic N. Results provide information to farmers on how to use broiler litter safely and efficiently in forage crop production.

Technical Abstract: Achieving adequate hay production from hybrid bermudagrass [Cynodon dactylon (L.) Pers.] when P nutrition is the basis for broiler litter applications requires supplementation with mineral N fertilizer. Field studies were conducted to determine if replacing broiler litter N with mineral N (ammonium nitrate, 34-0-0) increases annual P uptake (=biomass yield x tissue concentration) in Coastal bermudagrass. Plots were established at Mize, MS, in a pasture with soil test (STP) of about 409 kg/ha, and at Newton, MS, in a pasture with STP of about 52 kg/ha. Litter rates of 0, 4.5, 8.9, 13.4, and 17.9 Mg/ha/yr were made in increments of 4.5 Mg/ha beginning in April, and were supplemented with 67 kg N/ha after each harvest to provide 269, 202, 134, 67, and 0 kg N/ha/yr, respectively. Treatments, including an unfertilized check, were repeated on the same plots in 1999, 2000, and 2001. Year significantly affected P uptake because of above average rainfall in 2001. In fertilized plots and in all three years, herbage P concentrations were greatest numerically in litter only treatments. Averaged across years, maximum P uptake of about 40 kg/ha corresponded to 8.9 Mg litter + 134 kg N/ha/yr treatment at Newton, and to 4.5 Mg litter + 202 kg N/ha/yr treatment at Mize. Results suggest combining broiler litter with mineral N has potential to enhance forage productivity and the uptake of litter nutrients by bermudagrass.