Assessing Marginal Land Availability Based on Land Use Change Information in the Contiguous United States.
23 Jul 2021-Environmental Science & Technology (American Chemical Society (ACS))-Vol. 55, Iss: 15, pp 10794-10804
TL;DR: In this article, the authors developed a novel framework to quantify marginal land for the Contiguous United States (CONUS) based on a history of satellite-observed land use change (LUC) over the 2008-2015 period.
Abstract: Utilization of marginal land for growing dedicated bioenergy crops for second-generation biofuels is appealing to avoid conflicts with food production. This study develops a novel framework to quantify marginal land for the Contiguous United States (CONUS) based on a history of satellite-observed land use change (LUC) over the 2008-2015 period. Frequent LUC between crop and noncrop is assumed to be an indicator of economically marginal land; this land is also likely to have a lower opportunity cost of conversion from food crop to bioenergy crop production. We first present an approach to identify cropland in transition using the time series of Cropland Data Layer (CDL) land cover product and determine the amount of land that can be considered marginal with a high degree of confidence vs with uncertainty across the CONUS. We find that the biophysical characteristics of this land and its productivity and environmental vulnerability vary across the land and lie in between that of permanent cropland and permanent natural vegetation/bare areas; this land also has relatively low intrinsic value and agricultural profit but a high financial burden and economic risk. We find that the total area of marginal land with confidence vs with uncertainty is 10.2 and 58.4 million hectares, respectively, and mainly located along the 100th meridian. Only a portion of this marginal land (1.4-2.2 million hectares with confidence and 14.8-19.4 million hectares with uncertainty) is in the rainfed region and not in crop production and, thus, suitable for producing energy crops without diverting land from food crops in 2016. These estimates are much smaller than the estimates obtained by previous studies, which consider all biophysically low-quality land to be marginal without considering economical marginality. The estimate of marginal land for bioenergy crops obtained in this study is an indicator of the availability of economically marginal land that is suitable for bioenergy crop production; whether this land is actually converted to bioenergy crops will depend on the market conditions. We note the inability to conduct field-level validation of cropland in transition and leave it to future advances in technology to ground-truth land use change and its relationship to economically marginal land.
Citations
More filters
29 citations
TL;DR: In this paper, the authors developed an integrated economic-biophysical model to quantify the water quality impacts of three potential policy scenarios that provided corn ethanol at levels before the RFS2 (RFS1 baseline); 15 billion gallons of corn ethanol (corn ethanol only); or 16 billion gallons (16 billion gallons) of cellulosic ethanol in addition to corn ethanol, corn + ethanol.
Abstract: Demand for biofuel production driven by the Renewable Fuel Standard (RFS2) has coincided with increased land in corn production and increasing nitrogen (N) loss to the Gulf of Mexico. Diversifying cropland with perennial energy crops (miscanthus and switchgrass) may reduce N loss and improve water quality. However, the extent of these benefits depends on the mix of biomass feedstocks (corn stover, perennials) incentivized by the RFS2 and the extent to which energy crops displace N-intensive row crops. We developed an integrated economic-biophysical model to quantify the water quality impacts of three potential policy scenarios that provided corn ethanol at levels before the RFS2 (RFS1 baseline); 15 billion gallons of corn ethanol (corn ethanol only); or 16 billion gallons of cellulosic ethanol in addition to corn ethanol (corn + cellulosic ethanol). Our results showed that economically optimal locations for perennial energy crop production were distributed across idle cropland with lower intrinsic N loss than active cropland. We found stover removal incentivized by the RFS2 offset N loss benefits of perennial energy crops. This finding suggests that targeted incentives for N loss reduction are needed to supplement the RFS2 to induce displacement of N-intensive row crops with energy crops to reduce N losses.
12 citations
TL;DR: In this article , the authors focus on the key economically important plants used for phytoremediation, as well as the challenges to plant growth and phytormediation capability with emphasis on the advantages and limits of plant growth in marginal land soil.
Abstract: Land that has little to no utility for agriculture or industry is considered marginal land. This kind of terrain is frequently found on the edge of deserts or other arid regions. The amount of land that can be used for agriculture continues to be constrained by increasing desertification, which is being caused by climate change and the deterioration of agriculturally marginal areas. Plants and associated microorganisms are used to remediate and enhance the soil quality of marginal land. They represent a low-cost and usually long-term solution for restoring soil fertility. Among various phytoremediation processes (viz., phytodegradation, phytoextraction, phytostabilization, phytovolatilization, phytofiltration, phytostimulation, and phytodesalination), the employment of a specific mechanism is determined by the state of the soil, the presence and concentration of contaminants, and the plant species involved. This review focuses on the key economically important plants used for phytoremediation, as well as the challenges to plant growth and phytoremediation capability with emphasis on the advantages and limits of plant growth in marginal land soil. Plant growth-promoting bacteria (PGPB) boost plant development and promote soil bioremediation by secreting a variety of metabolites and hormones, through nitrogen fixation, and by increasing other nutrients’ bioavailability through mineral solubilization. This review also emphasizes the role of PGPB under different abiotic stresses, including heavy-metal-contaminated land, high salinity environments, and organic contaminants. In our opinion, the improved soil fertility of marginal lands using PGPB with economically significant plants (e.g., Miscanthus) in dual precession technology will result in the reclamation of general agriculture as well as the restoration of native vegetation.
6 citations
TL;DR: In this article , the authors provide an in-depth review of alternative technologies for sustainable aviation revealed to date, which are classified into four main categories, namely i) bio-fuels, ii) electro-fins, iii) electric (battery-based), and iv) hydrogen aviation.
3 citations
TL;DR: A growing portfolio of satellite data products is available to support the transition to a sustainable energy system as discussed by the authors , which poses a massive challenge to communities, nations and the global economy in the next decade and beyond.
Abstract: Transitioning to a sustainable energy system poses a massive challenge to communities, nations, and the global economy in the next decade and beyond. A growing portfolio of satellite data products is available to support this transition. Satellite data complement other information sources to provide a more complete picture of the global energy system, often with continuous spatial coverage over targeted areas or even the entire Earth. We find that satellite data are already being applied to a wide range of energy issues with varying information needs, from planning and operation of renewable energy projects, to tracking changing patterns in energy access and use, to monitoring environmental impacts and verifying the effectiveness of emissions reduction efforts. While satellite data could play a larger role throughout the policy and planning lifecycle, there are technical, social, and structural barriers to their increased use. We conclude with a discussion of opportunities for satellite data applications to energy and recommendations for research to maximize the value of satellite data for sustainable energy transitions.
2 citations
References
More filters
TL;DR: The tutorial provided in this paper reviews both binary morphology and gray scale morphology, covering the operations of dilation, erosion, opening, and closing and their relations.
Abstract: For the purposes of object or defect identification required in industrial vision applications, the operations of mathematical morphology are more useful than the convolution operations employed in signal processing because the morphological operators relate directly to shape. The tutorial provided in this paper reviews both binary morphology and gray scale morphology, covering the operations of dilation, erosion, opening, and closing and their relations. Examples are given for each morphological concept and explanations are given for many of their interrelationships.
2,676 citations
TL;DR: The National Agricultural Statistics Service (NASS) of the US Department of Agriculture (USDA) produces the Cropland Data Layer (CDL) product, which is a raster-formatted, geo-referenced, crop-specific, land cover map as mentioned in this paper.
Abstract: The National Agricultural Statistics Service (NASS) of the US Department of Agriculture (USDA) produces the Cropland Data Layer (CDL) product, which is a raster-formatted, geo-referenced, crop-specific, land cover map. CDL program inputs include medium resolution satellite imagery, USDA collected ground truth and other ancillary data, such as the National Land Cover Data set. A decision tree-supervised classification method is used to generate the freely available state-level crop cover classifications and provide crop acreage estimates based upon the CDL and NASS June Agricultural Survey ground truth to the NASS Agricultural Statistics Board. This paper provides an overview of the NASS CDL program. It describes various input data, processing procedures, classification and validation, accuracy assessment, CDL product specifications, dissemination venues and the crop acreage estimation methodology. In general, total crop mapping accuracies for the 2009 CDLs ranged from 85% to 95% for the major crop categories.
788 citations
TL;DR: The area with the greatest potential for yielding biomass energy that reduces net warming and avoids competition with food production is land that was previously used for agriculture or pasture but that has been abandoned and not converted to forest or urban areas.
Abstract: Increased production of biomass for energy has the potential to offset substantial use of fossil fuels, but it also has the potential to threaten conservation areas, pollute water resources and decrease food security. The net effect of biomass energy agriculture on climate could be eithercoolingor warming, depending on the crop,the technology for converting biomass into useable energy, and the difference in carbon stocks and reflectance of solar radiation between the biomass crop and the preexisting vegetation. The area with the greatest potential for yielding biomass energy that reduces net warming andavoidscompetitionwithfoodproduction islandthat was previously used for agriculture or pasture but that has been abandoned and not converted to forest or urban areas. At the global scale, potential above-ground plant growth on these abandoned lands has an energy content representing � 5% of world primary energy consumption in 2006. The global potential for biomass energy production is large in absolute terms, but it is notenoughtoreplacemore thana fewpercentof current fossil fuel usage. Increasing biomass energy production beyond this level would probably reduce food security and exacerbate forcing of climate change. Biomass energy in context Biomass energy sources are among the most promising, most hyped and most heavily subsidized renewable energy sources. They have real potential to heighten energy security in regions without abundant fossil fuel reserves, to increase supplies of liquid transportation fuels and to decrease net emissions of carbon into the atmosphere per unit of energy delivered. However, increased exploitation of biomass energy also risks sacrificing natural areas to managed monocultures, contaminating waterways with agricultural pollutants, threatening food supplies or farm lifestyles through competition for land and increasing net emissions of carbon to the atmosphere, as a consequence of increased deforestation or energy-demanding manufacturing technologies. The opportunities are real, but the concerns are also justified. As investments in biomass energy increase, there needs to be an active, continuing discussion on strategies for balancing the pros and cons of biomass energy. The future of biomass energy in the global energy system is dependent on the complex interplay of four major factors. The first is conversion technology and the prospects for using new plant and microbe varieties as well as novel biomass-to-fuel conversion processes for increasing the yield of usable energy from each unit of available land or water. The second is the intrinsic productive capacity of the land and ocean ecosystems that can be used for biomass energy production. The third is alternative uses for the land and water resources that are candidate sites for biomass energy production. The fourth is offsite implications of biomass energy technologies for invasive species [1] and for levels of air and water pollution. These factors must be effectively integrated to maximize the benefits and minimize the ecosystem and societal costs of biomass energy production. In particular, constraints owing to ecosystem characteristics, competition from alternative land uses and offsite impacts can lead to practical or desirable levels of biomass energy production that are much smaller than theoretical potential levels. A clear picture of these constraints can be an important asset in encouraging rational development of the biomass energy industry. In this article we briefly review all four of these factors, with an emphasis on their integration. We first discuss the main types of biomass energy production systems, their relative efficiencies, and their environmental impacts. Next, we consider the role of existing vegetation in the distinction between energy and climate security, arguing that biomass energy production on current forest or crop lands is unlikely to result in significant climate benefits relative to fossil fuel use. Finally, we assess the potential total production of biomass on land other than forests or croplands.
708 citations
TL;DR: The potential for marginal lands in ten Midwestern US states to produce sizeable amounts of biomass and concurrently mitigate greenhouse gas emissions is evaluated, finding that successional herbaceous vegetation, once well established, has a direct GHG emissions mitigation capacity that rivals that of purpose-grown crops.
Abstract: A comparative assessment of six alternative cropping systems over 20 years shows that, once well established, successional herbaceous vegetation grown on marginal lands has a direct greenhouse gas emissions mitigation capacity that rivals that of purpose-grown crops. Productive agricultural land that could otherwise be used to produce much-needed food crops is being diverted towards grain-based ethanol production in both Europe and the United States, partly in response to government legislation. An alternative is to grow cellulosic crops on so-called marginal lands. An evaluation of the potential of marginal lands in the Midwestern United States to produce biofuel while mitigating direct greenhouse gas emissions now finds that they have the capacity to produce a significant amount of biofuel energy without the initial carbon debt and indirect land-use costs associated with food-based biofuels. Legislation on biofuels production in the USA1 and Europe2,3 is directing food crops towards the production of grain-based ethanol2,3, which can have detrimental consequences for soil carbon sequestration4, nitrous oxide emissions5, nitrate pollution6, biodiversity7 and human health8. An alternative is to grow lignocellulosic (cellulosic) crops on ‘marginal’ lands9. Cellulosic feedstocks can have positive environmental outcomes10,11 and could make up a substantial proportion of future energy portfolios12,13. However, the availability of marginal lands for cellulosic feedstock production, and the resulting greenhouse gas (GHG) emissions, remains uncertain. Here we evaluate the potential for marginal lands in ten Midwestern US states to produce sizeable amounts of biomass and concurrently mitigate GHG emissions. In a comparative assessment of six alternative cropping systems over 20 years, we found that successional herbaceous vegetation, once well established, has a direct GHG emissions mitigation capacity that rivals that of purpose-grown crops (−851 ± 46 grams of CO2 equivalent emissions per square metre per year (gCO2e m−2 yr−1)). If fertilized, these communities have the capacity to produce about 63 ± 5 gigajoules of ethanol energy per hectare per year. By contrast, an adjacent, no-till corn–soybean–wheat rotation produces on average 41 ± 1 gigajoules of biofuel energy per hectare per year and has a net direct mitigation capacity of −397 ± 32 gCO2e m−2 yr−1; a continuous corn rotation would probably produce about 62 ± 7 gigajoules of biofuel energy per hectare per year, with 13% less mitigation. We also perform quantitative modelling of successional vegetation on marginal lands in the region at a resolution of 0.4 hectares, constrained by the requirement that each modelled location be within 80 kilometres of a potential biorefinery. Our results suggest that such vegetation could produce about 21 gigalitres of ethanol per year from around 11 million hectares, or approximately 25 per cent of the 2022 target for cellulosic biofuel mandated by the US Energy Independence and Security Act of 2007, with no initial carbon debt nor the indirect land-use costs associated with food-based biofuels. Other regional-scale aspects of biofuel sustainability2, such as water quality11,14 and biodiversity15, await future study.
628 citations
TL;DR: The global potential for bioenergy on abandoned agriculture lands is shown to be less than 8% of current primary energy demand, based on historical land use data, satellite-derived land cover data, and global ecosystem modeling.
Abstract: Converting forest lands into bioenergy agriculture could accelerate climate change by emitting carbon stored in forests, while converting food agriculture lands into bioenergy agriculture could threaten food security. Both problems are potentially avoided by using abandoned agriculture lands for bioenergy agriculture. Here we show the global potential for bioenergy on abandoned agriculture lands to be less than 8% of current primary energy demand, based on historical land use data, satellite-derived land cover data, and global ecosystem modeling. The estimated global area of abandoned agriculture is 385-472 million hectares, or 66-110% of the areas reported in previous preliminary assessments. The area-weighted mean production of above-ground biomass is 4.3 tons ha(-1) y(-1), in contrast to estimates of up to 10 tons ha(-1) y(-1) in previous assessments. The energy content of potential biomass grown on 100% of abandoned agriculture lands is less than 10% of primary energy demand for most nations in North America, Europe, and Asia, but it represents many times the energy demand in some African nations where grasslands are relatively productive and current energy demand is low.
619 citations