Impacts of management practices on bioenergy feedstock yield and economic feasibility on Conservation Reserve Program grasslands
- Anderson, Eric K [ Univ Illinois, Dept Crop Sci, AW-101 Turner Hall,1102 S Goodwin Ave, Urbana, IL 61801 USA ]
- Aberle, Ezra [ North Dakota State Univ, Carrington Res Extens Ctr, 663 Hwy 281 N,POB 219, Carrington, ND 58421 USA ]
- Chen, Chengci [ Montana State University: Research Centers ]
- Egenolf, Josh [ Univ Georgia, Odum Sch Ecol, Athens, GA 30602 USA ]
- Harmoney, Keith [ Kansas State Univ, Agr Res Ctr, Hays, KS 67601 USA ]
- Kakani, Vijaya Gopal [ Oklahoma State Univ, Dept Plant & Soil Sci, 368 Agr Hall, Stillwater, OK 74078 USA ]
- Kallenbach, Robert [ Univ Missouri, Div Plant Sci, Waters 108, Columbia, MO 65211 USA ]
- Wang, Weiwei [ Univ Illinois, Dept Agr & Consumer Econ, 326 Mumford Hall,1301 W Gregory Dr, Urbana, IL 61801 USA ]
- Lee, DoKyoung [ Univ Illinois, Dept Crop Sci, AW-101 Turner Hall,1102 S Goodwin Ave, Urbana, IL 61801 USA ]
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.