Broiler (Gallus gallus) litter fertility regimes and nutrient removal by sorghum-sudangrass [Sorghum bicolor (L.) Moench] are not well defined. The objective of this study was to determine broiler litter fertility regimes for sorghum-sudangrass that would maximize nutrient removal and produce comparable forage nutritive value compared with inorganic fertilizers while reducing potential soil nutrient accumulation. A randomized, complete-block experiment with four replications and four treatments (litter applied at recommended nitrogen [N] rate [Litter-N], recommended phosphorus [P] rate plus supplemental inorganic N [Litter-P1N], recommended P rate [Litter-P], and inorganic fertilizer [INORG]) was established. Acid detergent fiber (ADF), neutral detergent fiber (NDF), crude protein (CP), P, Cu, Fe, and Zn were determined. Treatments did not affect ADF, NDF, Cu, or Fe in 2001, whereas ADF and NDF were similar for INORG and Litter-N in 2002. Greatest P concentrations were observed in Litter-N and Litter-P plots. Crude protein was greatest for INORG plots, similar for Litter-P1N and Litter-N treatments, and lowest for Litter-P plots. Treatments affected Cu and Zn: Forage from Litter-N plots contained 44% greater forage Cu than those from Litter-P plots in 2003. Iron concentration for 2003 was 60% higher than for 2001 in Litter-N plots, and there were 22% and 30% increases in P uptake in 2003 compared with 2001 for the Litter-N and Litter-P1N plots, respectively. Lower rates of broiler litter, applied based on the P requirement and supplemented with inorganic N, can produce similar forage nutritive value to that fertilized with inorganic fertilizer only or broiler litter applied to meet crop N requirements.

Norflurazon adsorption and dissipation under field and laboratory conditions, and distribution within the soil profile were determined in three soils representative of cotton-growing regions of the southeastern U.S. Norflurazon adsorption was greater in soil from 0 to 8 cm in a Lexington silt loam (Tennessee) and a Beulah silt loam (Mississippi) than in a Dothan loamy sand (Georgia). Adsorption was directly related to organic matter. Norflurazon degradation under controlled conditions in soil from 0 to 8 cm from each state was not different among locations, with half-lives ranging from 63 to 167 d. Degradation at 30 C in soil from the 30- to 45- and 60- to 90-cm depths was not different among locations, and was slower at the 60- to 90-cm depth than in surface soil. Norflurazon dissipation was more rapid under field conditions than under laboratory conditions, with half-lives ranging from 7 to 79 d in the 0- to 8-cm soil horizon. Dry field conditions slowed norflurazon dissipation. Norflurazon was not detected below 15 cm in the profile in any soil, and concentrations in the 8- to 15-cm soil zone were < 36 ppbw 112 d after treatment.

Fluometuron adsorption and dissipation under field and laboratory conditions, and distribution within the soil profile was determined in 3 soils from Tennessee, Mississippi, and Georgia that are representative of the cotton-growing regions of the southeastern United States. Fluometuron adsorption was correlated with organic matter, but not with clay content or soil pH. First-order kinetics explained fluometuron dissipation under field and controlled conditions (r2≥ 0.82). Field dissipation of fluometuron was slower under dry conditions. Fluometuron was not detected below 15 cm in the soil profile in any soil, and concentrations in the 8- to 15-cm soil zone were < 15 ppbw 112 d after treatment. Fluometuron dissipation was more rapid in soil from the 0- to 8-cm depth in Tennessee soil than in Mississippi soil under controlled conditions. Dissipation was more rapid under field conditions than under laboratory conditions at 2 of 3 locations. Fluometuron half-lives in soils from the 0- to 8-cm depth ranged from 9 to 28 d under field conditions and from 11 to 43 d in the laboratory. Fluometuron dissipation in soils from 30- to 45- and 60- to 90-cm depths was not different among soils, with half-lives ranging from 58 to 99 d under laboratory conditions. Fluometuron half-life was positively correlated with soil depth and inversely correlated with organic matter. These data indicate that organic matter, soil depth, and environmental conditions affect fluometuron dissipation.

A rapid, sensitive method for the determination of norflurazon in 4 soils is described. Data on the initial soil metabolite is also obtained in soils with low organic matter. The method consists of extraction of soil samples with methanol, filtration, liquid chromatographic separation of methanol-soluble components by using a C18 column, and fluorescence detection with excitation at 294 nm and emission measured at 398 nm. Recoveries from fortified soils were &gt;90% for norflurazon and &gt;80% for desmethylnorflurazon from the Shipps, Lexington, and Harkey soils. Average percent relative standard deviations over the soils examined was 5.5% for norflurazon and 8.7% for desmethylnorflurazon. The limit of detection for norflurazon was 10 ng/g soil, whereas the limit of detection for desmethylnorflurazon was 100 ng/g soil because of its smaller relative detector response.

Excessive nutrient accumulation in soils due to land application of broiler litter is a growing environmental concern. A four‐year study was conducted on a Pembroke silt loam soil (Mollic Paleudalf) cropped to orchardgrass (Dactylis glomerataL.) to evaluate accumulation of soil nutrients from broiler litter application. A randomized complete block design with four fertilization treatments was used. Broiler litter was applied at recommended nitrogen rate (L‐N), recommended phosphorus rate (L‐P), recommended phosphorus rate supplemented with inorganic nitrogen (L‐P+N) and inorganic fertilizer with no litter application (Inorg). The L‐P, L‐P+N, and Inorg treatments did not cause an increase in soil nutrient accumulation while L‐N increased soil phosphorus, copper, and zinc by five‐fold compared to values at initiation of this experiment. Maximum and minimum orchardgrass yields were observed with L‐N (18,019 kg/ha DM) and L‐P treatments (7189 kg/ha DM). According to our findings, applying broiler litter at the recommended phosphorus rate and supplementing with inorganic nitrogen may be an environmentally sustainable broiler litter management practice.