Impacts of management practices on bioenergy feedstock yield and economic feasibility on Conservation Reserve Program grasslands |
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| Authors: | Eric K Anderson Ezra Aberle Chengci Chen Josh Egenolf Keith Harmoney Vijaya Gopal Kakani Robert Kallenbach Madhu Khanna Weiwei Wang DoKyoung Lee |
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| Affiliation: | 1. Department of Crop Sciences, University of Illinois Urbana‐Champaign, Urbana, IL, USA;2. Carrington Research Extension Center, North Dakota State University, Carrington, ND, USA;3. Central Agricultural Research Center, Montana State University, Moccasin, MT, USA;4. Odum School of Ecology, The University of Georgia, Athens, GA, USA;5. Agricultural Research Center, Kansas State University, Hays, KS, USA;6. Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK, USA;7. Division of Plant Sciences, University of Missouri, Columbia, MO, USA;8. Department of Agricultural and Consumer Economics, University of Illinois Urbana‐Champaign, Urbana, IL, USA |
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| Abstract: | Perennial grass mixtures planted on Conservation Reserve Program (CRP) land are a potential source of dedicated bioenergy feedstock. Long‐term nitrogen (N) and harvest management are critical factors for maximizing biomass yield while maintaining the longevity of grass stands. A six‐year farm‐scale study was conducted to understand the impact of weather variability on biomass yield, determine optimal N fertilization and harvest timing management practices for sustainable biomass production, and estimate economic viability at six CRP sites in the United States. Precipitation during the growing season was a critical factor for annual biomass production across all regions, and annual biomass production was severely reduced when growing season precipitation was below 50% of average. The N rate of 112 kg ha?1 produced the highest biomass yield at each location. Harvest timing resulting in the highest biomass yield was site‐specific and was a factor of predominant grass type, seasonal precipitation, and the number of harvests taken per year. The use of N fertilizer for yield enhancement unambiguously increased the cost of biomass regardless of the harvest timing for all six sites. The breakeven price of biomass at the farmgate ranged from $37 to $311 Mg?1 depending on the rate of N application, timing of harvesting, and location when foregone opportunity costs were not considered. Breakeven prices ranged from $69 to $526 Mg?1 when the loss of CRP land rental payments was included as an opportunity cost. Annual cost of the CRP to the federal government could be reduced by over 8% in the states included in this study; however, this would require the biomass price to be much higher than in the case where the landowner receives the CRP land rent. This field research demonstrated the importance of long‐term, farm‐scale research for accurate estimation of biomass feedstock production and economic viability from perennial grasslands. |
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| Keywords: | biomass breakeven price cool‐season mixture harvest management nitrogen management opportunity cost perennial grasses warm‐season mixture |
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