Publication Date:
2015-12-22
Description:
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 U.S. 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 were included as opportunity costs. 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. This article is protected by copyright. All rights reserved.
Print ISSN:
1757-1693
Electronic ISSN:
1757-1707
Topics:
Energy, Environment Protection, Nuclear Power Engineering
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