Nitrogen and harvest management of Conservation Reserve Program (CRP) grassland for sustainable biomass feedstock production

Abstract

The Biomass Regional Feedstock Partnership has identified grasslands planted under the Conservation Reserve Program (CRP) as a potential source for herbaceous bioenergy feedstock. The goal of this project is to assess the yield potential of CRP grasslands across diverse regions. Consistent with that goal, the objective of this project was to establish yield potential and quality parameters for several different CRP grasslands, representative of different growing environments. Standard field scale agricultural practices were used as management guidelines at each location. The test locations were identified and established based on known regions containing concentrated tracts of CRP grassland and represented variable climatic parameters and production histories. Biomass production potential for CRP land dominated by either warm-or cool-season grass mixtures in each location was evaluated over the course of three growing seasons (2008, 2009, and 2010). Specifically, a mixture of warmseason perennial grasses was evaluated in North Dakota, Kansas, and Oklahoma, while a cool-season mixture was evaluated in Montana, Georgia, and Missouri. Maximum biomass yields for the three warm-season CRP sites ranged from 4.0 to 7.2 Mg ha À1 and for the three cool-season CRP sites 3.4-6.0 Mg ha À1 . Our results demonstrate that CRP grassland has potential as a bioenergy feedstock resource if the appropriate management practices are followed.

Energy Potential of Biomass from Conservation Grasslands in Minnesota, USA

“…Elevated levels of soil N–NO 3 could come as a result of N fertilizer, which has been considered as a management tool to increase biomass yields in conservation grasslands [8], [23]. Fertilization experiments show that higher N fertilizer rates lead to higher concentrations of N in biomass tissue for C3-dominated mixed grasslands [49], for switchgrass [50], and other C4 grasses [51].…”

“…This has initiated questions regarding the economic viability of diverse grassland bioenergy, yet few studies have quantified bioenergy yields from diverse perennial plantings over multiple years. Only recently have studies compared the bioenergy potential of mixed-species grasslands harvested with production-scale techniques in various regions of the Upper Midwest [8].…”

“…One means of measuring biomass quantity is to multiply yields from CRP fields in different regions of North America by estimates of available acreage [8], [14]–[16]. These yields can then be extrapolated to estimate biomass from land not currently enrolled in, but eligible for conservation programs.…”

Carbon and nitrogen dynamics in bioenergy ecosystems: 2. Potential greenhouse gas emissions and global warming intensity in the conterminous United States

“…By classifying the land productivity according to soil productivity, topography, climate regimes, and other indicators, Cai et al ., () estimated a total of 43–123 Mha of land with marginal productivity in the United States. Other possible land sources including abandoned agricultural lands (Campbell et al ., ), degraded grassland (Wicke et al ., ) and Conservation Reserve Program grassland (Lee et al ., ) may also contribute to the production of biomass. With crop‐specific selection, these lands may potentially serve as land sources for planting cellulosic crops.…”

Biomass Yield of Warm‐Season Grasses Affected by Nitrogen and Harvest Management

“…Although numerous studies have been conducted to investigate the individual impacts of N fertilizer management and harvest regime on switchgrass biomass yield, only a few studies examined these factors simultaneously (Vogel et al, 2002;Guretzky et al, 2011;Lee et al, 2013;Seepaul et al, 2014).…”