Ryegrass–Bermudagrass Production and Nutrient Uptake when Combining Nitrogen Fertilizer with Broiler Litter

A common problem when broiler litter is applied to pastures in the southeastern USA is the buildup of soil P because of the difference in N–P–K ratio of the broiler litter and forage crop requirements. A study was conducted to test the theory that if the N requirement of the forage crop is only partially met by the broiler litter, application of commercial N fertilizer would stimulate plant growth to remove excess soil P and K. A small‐plot study was conducted for 2 yr combining 9 Mg ha −1 broiler litter applied in October with various combinations of 56 kg N ha −1 applied in December, March, May, and July to an annual ryegrass ( Lolium multiflorum L.)–‘Coastal’ bermudagrass [ Cynodon dactylon (L.) Pers.] pasture system. Yield increased from 8.9 to a maximum of 13.4 Mg ha −1 when 56 kg N ha −1 was applied up to three times a year. Nitrogen uptake was directly related to the amount of N fertilizer applied, with a maximum of 285 kg N ha −1 removed following four applications. The most P and K was removed when N was applied in December and March or March and May. These treatments removed 23% more P and 43% more K than when no commercial N was applied. Ryegrass removed twice as much P and K as bermudagrass. Combining broiler litter with commercial N fertilizer as a nutrient source for pastures was an effective method to increase P and K uptake from an annual ryegrass–bermudagrass pasture.