Establishing energy grasses in sprayfields
As part of its project to establish energy grasses in the southeastern part of the state on hog lagoon sprayfields and verify the economic opportunities for biofuels, the Biofuels Center has planted energy grasses on a number of locations in several counties. This project is being developed in partnership with ethanol companies, pork integrators, the N.C. Pork Council, N.C. State University, and N.C. Department of Environment and Natural Resources.
The Cottle Farm near Kenansville (the Murphy-Brown site) and the Williamsdale Biofuels Farm near Wallace (the N.C. State University energy crops field laboratory) have been planted with annual crops for several years. As a result, these sites have proved to be relatively easy to prepare and plant. During May and June of 2011, Sweet Sorghum, Forage Sorghum, Switchgrass, Giant Miscanthus, and Coastal Bermudagrass were planted on both sites. The Cottle Farm will be under the same nutrient application practices that are typical for Coastal Bermudagrass used on hog lagoon sprayfields.
The Williamsdale Biofuels Farm is a control site where several different rates of commercial nitrogen will be applied to all crops. This will enable researchers and the Center to compare how these crops respond to the lack of nitrogen versus relatively high rates of nitrogen. In the future, this information will be used to determine more accurately the practical rates of nitrogen that can be applied from hog lagoon effluent.
The Prestage Farms site (the Keener Farm near Clinton) and the Maxwell Foods site (near Goldsboro) have been established with Coastal Bermudagrass for many years. Eliminating the existing Bermudagrass has been challenging. There have been two applications of the systemic herbicide, glyphosate. A third application plus two preemergent herbicides were applied in June of 2011. The shading from the tall sorghum helped in eliminating the Bermudagrass. The results of this process were evaluated in the fall of 2011 after the harvest of the sorghum, providing the basis for next steps to be determined. This process enabled plots to be ready for the establishment of perennials in the fall of 2011, and the annuals were fully planted and established in the spring of 2012.
The learning gained from eradication of Bermudagrass and establishment of perennial energy grasses will be valuable as research plot information is expanded to commercial-scale farming operations.