Research Accomplishment Reports 2011

Fate, Transport, and Ecological Effects of Livestock Antibiotics in Manure-Amended Agroecosystems

E. D'Angelo
Department of Plant and Soil Sciences

 

Non-Technical Summary

Arsenic and other antibiotics are widely fed to broiler chickens, and high concentrations of these compounds are commonly found in poultry litter. While poultry litter is considered a valuable fertilizer source when applied to agricultural soils, repeated and intense applications of litter can also contaminate surface and groundwater with arsenic and other livestock antibiotics, which poses health risks to people living in areas where poultry manure is used as a soil amendment. Little is known about the factors that regulate the occurrence and effects these compounds in the environment (e.g. bacterial diversity, development of antibiotic resistant bacteria, carbon and nutrient cycling, etc.).

Under certain environmental conditions, human and animal pathogens can acquire antibiotic resistance by genetic mutation and gene transfer from ARB. Objective 1 of this project will show whether livestock antibiotics affect soil bacteria diversity at different topographic positions (soil catenas) in the landscape. Results from this project will be useful for making improved management decisions about when and where to apply manure in order to maximize the benefits and minimize the ecological/health risks. Thus, the proposed research has a direct impact on both production agriculture and natural resource management in Kentucky and the nation.

Information about As levels and speciation in poultry manure determined in Objective 2 is critical for assessing health risks associated with applying large amounts of manure to the environment.

Information about the effect of tillage and manure application timing on As migration to the subsurface as addressed in Objective 3 would be useful for (i) predicting the fate and ecological effects of As and (ii) developing widely applicable best management practices that will maximize the benefits and minimize the health/ecological consequences of land application of manure wastes.

Results from the project will be disseminated through several outlets in order to inform scientists, Kentucky agricultural producers, and the public about the ecological and health consequences of applying poultry manure with As to agricultural fields. Results from the project will be (i) published in two refereed scientific journals, (ii) published as a Ph.D thesis, (iii) presented at local, regional, and national scientific conferences (e.g. American Society of Agronomy), (iv) published as two extension publications (e.g. Soil Science News and Views) and (v) posted on the extension Plant and Soil Sciences department web site.