A team led by sustainability theme leader Madhu Khanna proposes a new use of land registered in the Conservation Reserve Program (CRP) which could be a “ win-win ” scenario for both the economy and the environment.
Researchers at the Center for Advanced Bioenergy and Bio-Product Innovation (CABBI) found that converting land registered in the Conservation Reserve Program (CRP) to bioenergy cultivation could be beneficial to US landowners, the government, and the environment.
The land registered in the CRP cannot currently be used to produce bioenergy crops, as high-yielding plants (such as miscanthus and switchgrass) are harvested to convert them into marketable bio-products that replace fossil fuels and coal-based energy. Established by the United States Department of Agriculture in 1985, it incentivizes landowners to retire from environmentally degraded crop lands, exchange agricultural productivity with native habitats and accept annual government payments in return.
As the world warms and its population expands dramatically, the global demand for food production is in conflict with declining agricultural productivity threatened by harsh climatic conditions. Therefore, allocating CRP lands to high-yielding energy biomass may eliminate the need for bioenergy and food crops to compete for space.
A team led by Madhu Khanna, Leader of Sustainability Theme at CABBI and PhD. Student Luoye Chen developed an integrated modeling approach to assess the viability of moving CRP lands in the eastern United States to permanent bioenergy crops. Their paper was published in Environmental Science and Technology In January 2021, the transition to land use is already viable provided certain key conditions are met.
“As advocates of a safer and more sustainable bio-economy, we must prioritize replacing fossil fuels,” said Khanna, who is also director of the Institute for Sustainability, Energy and the Environment (iSEE) at the University of Illinois, Urbana-Champaign. “As scientists, it is our responsibility to take a thoughtful and innovative approach to mitigating greenhouse gases in a way that will prove beneficial in the long term.
The transport and electricity sectors are looking to expand production of bioenergy, and it is imperative that the agricultural sector do the same. This necessitates a program in which bioenergy cropland and food crop land coexist rather than compete.
The CABBI team takes an integrated approach to weighing the costs and benefits of switching the status quo of CRP – the uncultivated area – for bioenergy, combining the Biofuel and Environmental Policy Analysis Model (BEPAM) with the Biogeochemical Model DayCent (Daily Time Step Version of the Century Model).
BEPAM assesses net profitability, answering the key question: What are the exact economic conditions that will motivate CRP landowners to switch to cropland for bioenergy? As an environmental counterpoint to BEPAM, DayCent simulates the full ecosystem impacts of transition in a given county, providing a ‘peek’ into the future and highlighting how this land use change affects factors such as crop productivity, nutrient exchange, and soil carbon sequestration.
A key component of this study is pooling data from both models to formulate a greenhouse gas life cycle (GHG) assessment, which calculates the total greenhouse gases mitigated through the process as a whole – from the physical act of agriculture to the introduction of clean energy into the bioeconomy.
“Really, assessing the entire life cycle is the key to understanding the big picture results of our research,” Chen said. “We take everything into account – the process of planting and harvesting the feedstocks, the carbon trapped in the soil, the fact that we will eventually replace fossil fuels with biofuels, and coal-based electricity with bioelectricity.
“Keeping this bottom line in mind links everything else to the ultimate goal of a net positive environmental impact.”
The team concluded that converting 3.4 million hectares of CRP land into bioenergy from 2016 to 2030 is economically and environmentally viable – under certain conditions.
Economically, all systems “work” if the market price for biomass is high and the government continues to distribute appropriate CRP land lease payments. These factors could ideally act as a counterweight: if biomass prices fall, substantial land rental payments may alleviate financial pressures from farmers and encourage their continued commitment to bioenergy Instead, higher biomass prices would justify relaxing government subsidies, saving taxpayers’ money. The team identified two ideal pairs: 1) Landlords receive 100 percent of their original government payments and sell biomass at $ 75 per metric ton. Or 2) Landowners receive 75 percent of their original payment and sell the biomass for $ 100 / metric ton. Ideally, both parties benefit.
Converting CRP lands into bioenergy can also result in significant greenhouse gas savings. Previous studies indicate that large “soil carbon debts” can accumulate at the start of a project, during years of forage and grass cultivation. However, taking into account the aforementioned full life cycle assessment, the research team determined that the long-term implications of replacing fossil fuel and coal-based energy with bio-products would offset this temporary loss.
Considering landowner’s income from biomass sales, savings in government payments to maintain a current record in CRP, the monetary benefits of greenhouse gas mitigation through fossil fuel displacement (quantified using the ‘social cost of carbon’), the total net worth of CRP land conversion into energy Vitality could reach $ 28 billion to $ 125 billion during the 2016-2030 period.
In addition to Chen and Khanna, the team includes postdoctoral researcher Elena Planck-Pettis, CABBI and iSEE, University of Illinois, Urbana-Champaign. Associate Professor Tara W. Hodeburg, CABBI, University of Idaho; Daniel Hellerstein, Economic Research Service, United States Department of Agriculture (USDA); Stephen Waller, Economic Research Service, USDA; And Professor Evan H. DeLuchia, CABBI, iSEE, University of Illinois, Urbana-Champaign.