Economic Competitiveness of Napier Grass in Irrigated and Non-irrigated Georgia Coastal Plain Cropping Systems

Abstract

Interest and focus on development of renewable biofuels has been increasing over the past decade leading to the introduction of a wide cadre of renewable feedstocks. As a result, numerous perennial warm-season grasses have been introduced and management practices evaluated to determine their suitability as biofuel feedstocks. BMerkeron^napier grass (Pennisetum purpureum) plots were established in 2010 and harvested during crop years 2011 through 2015 adjacent to an ongoing peanut (Arachis hypogaea L.), corn (Zea mays L.), and cotton (Gossypium hirsutum L.) cropping systems study conducted at the USDA/ARS Multi-crop Irrigation Research Farm in Shellman, GA (84 36 W, 30 44 N) on a Greenville fine sandy loam (fine, kaolinitic, thermic Rhodic Kandiudults). Napier grass was produced in both non-irrigated and two irrigated levels with different levels of nitrogen and potassium fertilizers. Peanut, corn, and cotton were produced in non-irrigated and full irrigation regimes. Breakeven prices for napier grass ranged from $65 to $84 Mg −1 at variable and total costs. The breakeven napier grass price was estimated such that the net returns were equal between napier grass and peanut, cotton, corn cropping systems. At variable production cost, comparative breakeven napier grass prices for non-irrigated, 50% irrigated, and full irrigated regimes were $77, $117, and $112 Mg −1 , respectively. Napier grass did not compete economically against traditional irrigated cropping systems. Depending on traditional crop prices and bioenergy feed stock prices, napier grass could offer economic opportunities in non-irrigated production environments, riparian buffer zone edges, or non-cropped marginal production areas.

Field Productivities of Napier Grass for Production of Sugars and Ethanol

“…Napier grass was selected as a bioenergy crop because it outproduces other perennial grasses for the Southeast, United States. 3 Three agronomic strategies were considered: single fertilizer application/single winter harvest; single fertilizer application/summer and winter harvests; double fertilizer application/summer and winter harvests. There are several advantages to using a multiple cut strategy.…”

“…Napier grass is also known as elephant grass (and Uganda grass). Annual production yields have exceeded 50 Mg/ha in studies from Puerto Rico and Thailand , and up to 30 Mg/ha in the southeastern U.S . Merkeron Napier grass also achieves full yield in the first year of establishment, , grows on a wide range of soils, is drought tolerant, and is well suited for production in low input production systems .…”

“…These are the interactions between crop management and processing quality, the interdependence of biofuel yield per hectare on biomass production versus process quality, and empirically determined ethanol yields based upon replicated field grown samples. Past field studies of Napier grass were limited to biomass production or used a general estimate of ethanol yield . For this study, Napier grass was grown for four years under three different crop management strategies with four field replicates that included a winter cutting or summer and winter cuttings.…”

“…Past field studies of Napier grass were limited to biomass production or used a general estimate of ethanol yield. 3 For this study, Napier grass was grown for four years under three different crop management strategies with four field replicates that included a winter cutting or summer and winter cuttings. The harvested biomass from years 2 and 4 were compared for composition and theoretical (e.g., maximum possible) ethanol yields on a mass basis.…”

Bio-aviation Fuel: A Comprehensive Review and Analysis of the Supply Chain Components

“…Nevertheless, there have been proposed demonstration facilities for the production of miscanthus-derived jet fuel (Ondrey, 2012;BBI International, 2018). • Napier grass or elephant grass (Pennisetum purpureum) is a perennial grass from the tropics with reported high yields of 20-140 t/ha/yr (Fontoura et al, 2015;Chang et al, 2017;Lamb et al, 2018;Rödl, 2018). It is a promising feedstock for the production of both solid and liquid biofuels (Fontoura et al, 2015;Lamb et al, 2018).…”