Species Composition Changes in Conservation Reserve Program (CRP) Grassland When Managed for Biomass Feedstock Production
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Grasslands enrolled in the Conservation Reserve Program (CRP) serve as one of the potential national herbaceous resources for use as a dedicated bioenergy feedstock. The goal of this project was to assess the yield potential and suitability of CRP grassland as a bioenergy feedstock source across the USA in regions with significant CRP land resources. In addition to that goal, one major objective of this project was to assess vegetation composition changes that also occurred on these different CRP grasslands over time with different harvest and fertilization management strategies. Three levels of nitrogen fertilization (0, 56, and 112 kg ha−1) and two harvest timings [peak standing crop (PSC) or end of growing season (EGS)] were evaluated for effects on biomass production and resulting species composition changes. Three sites in regions containing concentrated tracts of CRP grassland and representing variable climatic parameters were analyzed for vegetation composition trends over the course of six growing seasons (2008–2013). Specifically, a mixture of warm-season perennial grasses was evaluated in Kansas (KS), while a cool-season mixture was evaluated in Missouri (MO). North Dakota (ND) contained a mixture of both warm- and cool-season grasses. At the MO and KS sites, nitrogen fertilization significantly altered the grass and legume composition over time by lowering the legume percentage in the stand. In KS and ND, the two sites with warm-season grasses, harvesting in mid-summer at PSC, greatly reduced warm-season grass composition over time in favor of annual cool-season grass invaders or perennial cool-season grasses. Any shift to less desirable or less productive species limits the ability of these lands to provide a sustainable or reliable feedstock for bioenergy production.
KeywordsWarm-season grass Cool-season grass Harvest management Nitrogen management Legumes Dry-weight-rank
This research was supported by the funding from the North Central Regional Sun Grant Center at South Dakota State University through a grant provided by the US Department of Energy Office of Biomass Programs under award number DE-FC36-05GO85041. We also express gratitude to Ryan Lock for suggested improvements to the manuscript.
Contribution no. 16-244-J from the Kansas Agricultural Experiment Station.
- 4.FAPRI (2007) Estimating water quality, air quality, and soil carbon benefits of the Conservation Reserve Program. FAPRI-UMC Report #01–07. Food and Agricultural Policy Research Institute, University of Missouri-Columbia, Columbia http://www.fsa.usda.gov/Assets/USDA-FSA-Public/usdafiles/EPAS/PDF/606586_hr.pdf. Accessed 24 Nov 2015Google Scholar
- 5.George JR, Blanchet KM, Gettle RM (2000) Growing legumes in mixtures with warm-season grasses. In: Moore KJ, Anderson BE (eds) Native warm-season grasses: research trends and issues. Crop Science Society of America and American Society of Agronomy, Madison, WI, pp. 67–82. doi: 10.2135/cssaspecpub30.c5 Google Scholar
- 11.Harmoney K, Jaeger J (2013) Precipitation effects on shortgrass rangeland: vegetation production and steer gain. Report of Progress 1086. Kansas State University Agricultural Experiment Station, Manhattan. Pgs. 36–41Google Scholar
- 15.Lindstrom MJ, Schumacher TE, Blecha ML (1994) Management considerations for returning CRP lands to crop production. J Soil Water Conserv 49:420–425Google Scholar
- 23.Mulligan KR, Barbato LS, Santosh S, Rainwater K, Smith L 2013. CRP effects on the Ogallala Aquifer. RWO 82. Final Report submitted to the United States Geological Survey. http://www.fsa.usda.gov/Assets/USDA-FSA-Public/usdafiles/EPAS/PDF/ceap2_rwo_82_final_050713.pdf. Accessed 24 Nov 2015
- 27.USDA-FSA. 2015. Conservation reserve program monthly summary—September 2015. http://www.fsa.usda.gov/Assets/USDA-FSA-Public/usdafiles/Conservation/PDF/sep2015summary.pdf. Accessed 20 Nov 2015