DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
Department of Agricultural and Consumer Economics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
Environ Sci Technol. 2021 Jan 19;55(2):1301-1309. doi: 10.1021/acs.est.0c06133. Epub 2021 Jan 7.
Using land already enrolled in the Conservation Reserve Program (CRP) in the eastern region of the U.S. for producing energy crops for bioenergy while reducing land rental payments offers the potential for lowering the program costs, increasing returns to CRP landowners, and displacing greenhouse gas (GHG) emissions from fossil fuels. We develop an integrated modeling approach to analyze the combination of biomass prices and CRP land rental payment reductions that can incentivize energy crop production on CRP land and its potential to increase soil carbon stocks and displace fossil fuel emissions. We find that conversion of 3.4 million ha in the CRP can be economically viable at a minimum biomass price of $75 Mg with full CRP land rental payment or at $100 Mg with 75% of this land rental payment; this conversion can result in savings of 0.52 and 1.25 billion Mg CO-eq in life-cycle emissions through the displacement of energy-equivalent fossil fuels and coal-based electricity, respectively, and an additional 0.11 billion Mg CO-eq soil carbon sequestration relative to the status quo, with CRP left unharvested over the 2016-2030 period. The soil carbon debt due to the transition from unharvested CRP land to energy crops is short-lived and more than offset by the reduction in fossil fuel emissions. The net discounted benefits from producing energy crops on CRP land through a reduced need for government payments to maintain existing enrollment, higher returns to CRP landowners, and the value of the reduction in GHG emissions could be as high as $16-$30 billion by using them for cellulosic biofuels to displace gasoline and $35-$68 billion by displacing coal-based electricity over the 2016-2030 period if biomass prices are $75-$125 Mg and land rental payments are reduced by 25%.
利用美国东部已纳入保护储备计划（CRP）的土地来生产生物能源所需的能源作物，同时降低土地租赁付款，这有可能降低项目成本，增加 CRP 土地所有者的回报，并减少温室气体（GHG）排放。我们开发了一种综合建模方法来分析生物质价格和 CRP 土地租赁付款减少的组合，这可以激励 CRP 土地上的能源作物生产，以及增加土壤碳储量和减少化石燃料排放的潜力。我们发现，在最低生物质价格为 75 美元/吨、CRP 土地租赁全额支付或 100 美元/吨、75%土地租赁支付的情况下，340 万公顷 CRP 土地的转换在经济上是可行的；通过替代能源等价化石燃料和基于煤炭的电力，这种转换可以在生命周期排放中节省 0.52 亿至 1.25 亿公吨二氧化碳当量，与现状相比，还可以额外增加 0.11 亿公吨二氧化碳当量的土壤碳封存，而 CRP 在 2016-2030 年期间则不会被收割。从未收割的 CRP 土地向能源作物过渡所产生的土壤碳债务是短暂的，并且由于化石燃料排放的减少而被大大抵消。通过减少维持现有登记所需的政府支付、增加 CRP 土地所有者的回报以及减少温室气体排放的价值，从 CRP 土地上生产能源作物的净贴现收益可能高达 160 亿至 300 亿美元，用于替代汽油的纤维素生物燃料，以及在 2016-2030 年期间通过替代基于煤炭的电力产生 350 亿至 680 亿美元的收益，如果生物质价格为 75-125 美元/吨，土地租赁支付减少 25%。
