Remote Sensing of Tall Fescue (Schedonorus arundinaceus) Plant Health with Varying Endophyte and Fertilizer Types: A Case for Improving Poultry Manuresheds

Abstract:

Tall fescue (Schedonorus arundinaceus) is a common perennial forage in cattle pastures of the southeastern United States. A mutualistic fungal endophyte normally infects the grass and produces ergot alkaloids toxic to livestock, but fungal biotypes that have no ergot alkaloid production have been developed. We used remote sensing methods to assess plant health in 1-ha grazed paddocks that different combinations of fertilizer source (inorganic and broiler litter) and endophyte association (wild, novel, and free). Broiler litter fertilization is common in the region from numerous chicken farms, and its price is comparable to inorganic fertilizer depending on distance from source to application. We tested the sensitivity of three indices: normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and land surface water index (LSWI) to assess plant health. Indices were obtained from satellite imagery provided by Landsat 7 ETM between the years 2005 and 2009. Sensitivity analytics suggested the best index to apply to the study area to determine fescue plant health. No difference in plant health (p>0.05, ANOVA test) was detected among fertilizer sources and endophyte associations. Without a significant difference, this research supports the recommendation of combining broiler litter with the MaxQ-type (novel) fescue to minimize detrimental impacts on cattle and improve manuresheds of the Georgia Piedmont.