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Herbaceous Crops On Marginal Sites — Erosion And Economics
Published 1989 · Environmental Science
Erosional and economic analyses of herbaceous energy cropping on marginal sites in the Virginia Piedmont have been conducted in conjunction with a US Department of Energy-funded project. Eight species (sorghum-sudangrass, switchgrass, weeping lovegrass, tall fescue, sericea lespedeza, flatpea, crownvetch, and birdsfoot trefoil) are being evaluated in a five-year study for their potential to produce biomass on three Virginia Piedmont soils (Appling, Cecil and Davidson) that are acidic and highly erodible. Erosional analyses using the Universal Soil Loss Equation suggested that no-till seeding methods and crop perenniality combine to produce low levels of erosion, even on highly erodible sites. Except for sorghum-sudangrass and birdsfoot trefoil grown on Cecil and Davidson soils, erosion levels, which ranged from 1.6 to 9.1 Mg ha−1, were within the US Soil Conservation Service tolerance levels and were not appreciably greater than the soil loss for undisturbed land, which ranged from 1.6 to 5.4 Mg ha−1. Economic analyses showed that annual costs for biomass production computed on the basis of land area or amount of biomass are quite species-dependent, and the high-yielding warm-season perennial grasses showed the most promise, based on the preliminary yield data obtained during the first three seasons. Per-unit costs of production of the energy crops were greatly influenced by land area in production and biomass yield.