Restricting Second-Generation Energy Crop Production to Marginal Land

Abstract

Production of switchgrass as a dedicated energy crop in the USA was proposed as a way to produce valuable products on millions of hectares that had been bid from traditional crop production by a variety of federal programs. The objective of the present study is to determine the expected economic consequences in terms of cost to deliver biomass feedstock, from restricting switchgrass production to marginal land for a case study region, when (a) land use is restricted to class IV; (b) land use is restricted to classes III and IV; and (c) use of land capability classes I, II, III, and IV is permitted. A hypothetical biorefinery with a processing capacity of 2000 Mg/day is assumed with switchgrass as the single biomass source. Soils and weather data were used in combination with crop management data to simulate switchgrass yields for each land capability class, for 50 years, for each of 30 Oklahoma counties. Land opportunity cost required to bid land from current use for each land capability class and each county were simulated based on the 2013 revealed county average Conservation Reserve Program (CRP) rental rates adjusted across capability class by relative productivity. A mathematical programming model was constructed and solved to determine the optimal quantity, location, and quality of the land leased. For the case study region, restricting land use to only capability class IV increases the land requirement by 44 % and increases the cost to deliver feedstock by 32 % compared to when switchgrass production is permitted on land classes I–IV.