Tommy Stephenson, Soil Science MS Student, Crop & Soil Sciences Department, NCSU.

Title: “Water Use of Bioenergy Cropping Systems in the North Carolina Piedmont”

Pre-seminar refreshments are served at 3:15 pm in the McKimmon Room (2223 WMS). Seminar begins at 3:40 pm in Williams Hall Auditorium (2215 WMS). Everyone is welcome to attend.

Abstract

Bioenergy crops are a potential alternative to traditional row crops and pasture/hay systems in the North Carolina piedmont, but there is limited information available about the water requirements of these crops and their water use efficiencies. The goal of this study is to evaluate the growth, water use, and yields of three potential bioenergy crops; switchgrass (Pancicum virgatum L.), giant miscanthus (Miscanthus x giganeus), and biomass sorghum (Sorghum bicolor spp.), and two traditional crops; corn silage (Zea mays L.) and fescue hay [Schedonorus arundinaceus (Schreb.) Dumort.]. Specific objectives are to quantify season long water use of these cropping systems and to develop crop coefficients to predict water use from reference evapotranspiration. The study was conducted at the piedmont research station in Salisbury North Carolina. The perennial systems were established in 2012 while annuals were planted each spring. Crop water use was evaluated for the 2016 and 2017 growing season using a water balance approach. Growth stage crop coefficients were developed from water balance data, and then used to predict season long water use of these systems using weather data. Giant miscanthus had the highest two year average biomass yield of 29.1 Mg ha^-1 followed by corn silage with 23.55 Mg ha^-1 and biomass sorghum at 22 Mg ha^-1. Fescue hay had the highest season-long water use both years of the study. Perennial grasses giant miscanthus and switchgrass both had similar seasonal water use but giant miscanthus had higher water use efficiency than switchgrass. The annual crops corn and sorghum both used less total water than the perennial systems because of their shorter growing season, and both had higher water use efficiencies. This information can aid growers when making management decisions about converting land into bioenergy cropping systems and managing the systems once they are in place.