Nitrogen extraction by cotton fertilized with broiler litter

Inefficient extraction, of litter-derived N and its loss to the immediate environment is a concern When poultry litter is used as a fertilizer. This research determined the magnitude of N extraction by cotton (Gossypium hirsutum L.) fertilized with broiler litter with or without supplemental inorganic N. Extraction of N by cotton fertilized with litter rates of 2.2, 4.5, and 6.7 Mg ha(-1) in combination with 0, 34, or 67 kg ha-1 N as urea-ammonium nitrate (UAN) was determined on two farms, one at Cruger and another at Coffeeville-MS, in 2002 to 2004. The treatment that received 4.5 Mg ha(-1) litter plus 67 kg ha(-1) UAN-N was among the treatments that had the largest N extraction with an average across years of 233 kg N ha(-1) total extraction at Cruger and 183 kg N ha(-1) at Coffeeville. These extractions were more or only slightly less than the total applied N. An average of 56% of extracted N at Cruger and 62% at Coffeeville was partitioned to seed and represents an lint, which represents an amount that would removed from the field. The remainder is bound in plant parts with little or no risk of becoming relealsed to the immediate environment until the plant parts decompose. These results demonstrate cotten is efficient at extracting N supplied by as much litter as 6.7 Mg ha(-1) when supplemented with inorganic N. The risk of N detrimentally affecting the immediate environment when cotten is fertilized with litter plus inorganic N is no greater than when fertilized with 100% inorganic N fertilizers.