Broiler litter x industrial by-products reduce nutrients and microbial losses in surface runoff when applied to forages

Authors: Adeli, Ardeshir; Read, John; Brooks, John; Miles, Dana; Feng, Gary; Jenkins, Johnie

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/2016
Publication Date: 3/17/2017
Publication URL: https://handle.nal.usda.gov/10113/5729150
Citation: Adeli, A., Read, J.J., Brooks, J.P., Miles, D.M., Feng, G.G., Jenkins, J.N. 2017. Broiler litter x industrial by-products reduce nutrients and microbial losses in surface runoff when applied to forages. Journal of Environmental Quality. 46:339-347.

Interpretive Summary: Broiler chicken (Gallus gallus) production is a major agricultural industry in the southeastern United States, and more than two-thirds of the total U.S. broiler production originates in this region. Recently, broiler litter became increasingly used as an alternative to and inexpensive source of fertilizer. Producers in regions with intense broiler production take advantage of the plant nutrients contained in broiler litter to enhance the yields of forage grasses or pasture nearby areas. The inability to incorporate manure into permanent pasture and hayfield leads to nutrients accumulation near the soil surface and potential for transport nutrient and pathogens off site by runoff water. Therefore, in recent years, researchers have searched for ways to mitigate and reduce the accumulation discharge of nutrients and pathogens from applied broiler litter into the environment. The objectives of this study were (1) to evaluate the effect of lignite and FGD gypsum with broiler litter application to hayfields on nutrients loss and microbial levels in runoff, (2) to determine the effectiveness of FGD and lignite on reducing P, N and microbial levels with the time of repeated rain events.

Technical Abstract: Rainfall simulations were used to determine the effect of broiler litter (BL) treated with N and P immobilizing agents on nutrient losses from a bermudagrass (Cynodon doctylon) hayfield on Marietta silt loam (Fine-loamy, siliceous, active, thermic Fluvaquentic Eutrudepts). The experimental design was a randomized complete block design with four treatments replicated three times. Treatments were no litter ( control), 13.4 Mg ha-1 litter treated with flue gas desulfurization (FGD) gypsum, and with lignite at 20% (dry weight, wt/wt). Repeated rain was applied with a 3 day interval to determine how long FGD gypsum and lignite are effective in protecting litter derived N, P and C from loss. Application of broiler litter substantially increased N, P and C concentrations in surface runoff as compared to the control (unfertilized). The addition of FGD gypsum reduced P in runoff by 76% as compared to broiler litter alone but was effective only at the first rain event. Lignite did not affect runoff P concentration, but significantly reduced runoff N by 60% as compared to litter alone. FGD gypsum was significantly effective in reducing P concentration only with the first rain event. Addition of FGD gypsum or lignite failed to significantly reduce microbial loads in runoff, though both reduced microbial levels by greater than 20%.Thus, broiler litter treated with FGD and lignite can be considered as a good management practice in mitigation of P and N and microbial levels in runoff, reduce water pollution and build healthy soil.