Marginal land is land that is of little agricultural or developmental value because crops produced from the area would be worth less than any rent paid for access to the area. [1] Although the term marginal is often used in a subjective sense for less-than-ideal lands, it is fundamentally an economic term [2] that is defined by the local economic context. Thus what constitutes marginal land varies both with location and over time: for example, "a soil profile with a set of specific biophysical characteristics reported as “marginal” in the US corn belt may be one of the better soils available in another context". [3] Changes in product values – such as the ethanol-demand induced spike in corn prices – can result in formerly marginal lands becoming profitable. [3] Marginal lands can therefore be more difficult to delineate as compared to "abandoned crop lands" which reflect more clearly definable landowner-initiated land use changes. [4]
Land may be marginal for a number of reasons, including poor water supply, poor soil quality, pollution from previous industrial activities, terrain challenges such as excessive slope, or excessive distance from means of transportation. [5]
Marginal land is not entirely useless for human purposes. For example, certain breeds of free-roaming livestock, such as the English Leicester sheep, are able to forage on such land. There are also some plants that can be grown in land that would be considered marginal for most agricultural uses. For example, Cucurbita foetidissima , the buffalo gourd, is well adapted to marginal agricultural lands such as sandy loam soils which have to be well-drained. [6] [7] Land that is marginal for conventional row-crop production is often well-suited to perennial crops, [8] including low-input crops grown as bioenergy or bioproduct feedstocks such as switchgrass (Panicum virgatum), shrub willow (Salix spp.), and giant miscanthus (Miscanthus x giganteus), allowing production of these crops without inducing competition for prime farmlands.
Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels such as oil. Biofuel can be produced from plants or from agricultural, domestic or industrial biowaste. Biofuels are mostly used for transportation, but can also be used for heating and electricity. Biofuels are regarded as a renewable energy source. The use of biofuel has been subject to criticism regarding the "food vs fuel" debate, varied assessments of their sustainability, and ongoing deforestation and biodiversity loss as a result of biofuel production.
Panicum virgatum, commonly known as switchgrass, is a perennial warm season bunchgrass native to North America, where it occurs naturally from 55°N latitude in Canada southwards into the United States and Mexico. Switchgrass is one of the dominant species of the central North American tallgrass prairie and can be found in remnant prairies, in native grass pastures, and naturalized along roadsides. It is used primarily for soil conservation, forage production, game cover, as an ornamental grass, in phytoremediation projects, fiber, electricity, heat production, for biosequestration of atmospheric carbon dioxide, and more recently as a biomass crop for the production of ethanol and butanol.
Cellulosic ethanol is ethanol produced from cellulose rather than from the plant's seeds or fruit. It can be produced from grasses, wood, algae, or other plants. It is generally discussed for use as a biofuel. The carbon dioxide that plants absorb as they grow offsets some of the carbon dioxide emitted when ethanol made from them is burned, so cellulosic ethanol fuel has the potential to have a lower carbon footprint than fossil fuels.
A biorefinery is a refinery that converts biomass to energy and other beneficial byproducts. The International Energy Agency Bioenergy Task 42 defined biorefining as "the sustainable processing of biomass into a spectrum of bio-based products and bioenergy ". As refineries, biorefineries can provide multiple chemicals by fractioning an initial raw material (biomass) into multiple intermediates that can be further converted into value-added products. Each refining phase is also referred to as a "cascading phase". The use of biomass as feedstock can provide a benefit by reducing the impacts on the environment, as lower pollutants emissions and reduction in the emissions of hazard products. In addition, biorefineries are intended to achieve the following goals:
Bioenergy is a type of renewable energy that is derived from plants and animal waste. The biomass that is used as input materials consists of recently living organisms, mainly plants. Thus, fossil fuels are not regarded as biomass under this definition. Types of biomass commonly used for bioenergy include wood, food crops such as corn, energy crops and waste from forests, yards, or farms.
Crop residues are waste materials generated by agriculture. The two types are:
Corn stover consists of the leaves, stalks, and cobs of corn (maize) plants left in a field after harvest. Such stover makes up about half of the yield of a corn crop and is similar to straw from other cereal grasses; in Britain it is sometimes called corn straw. Corn stover is a very common agricultural product in areas of large amounts of corn production. As well as the non-grain part of harvested corn, the stover can also contain other weeds and grasses. Field corn and sweet corn, two different types of maize, have relatively similar corn stover.
Cenchrus purpureus, synonym Pennisetum purpureum, also known as Napier grass, elephant grass or Uganda grass, is a species of perennial tropical grass native to African grasslands. It has low water and nutrient requirements, and therefore can make use of otherwise uncultivated lands.
Energy forestry is a form of forestry in which a fast-growing species of tree or woody shrub is grown specifically to provide biomass or biofuel for heating or power generation.
Energy crops are low-cost and low-maintenance crops grown solely for renewable bioenergy production. The crops are processed into solid, liquid or gaseous fuels, such as pellets, bioethanol or biogas. The fuels are burned to generate electrical power or heat.
Biochar is charcoal, sometimes modified, that is intended for organic use, as in soil. It is the lightweight black remnants, consisting of carbon and ashes, remaining after the pyrolysis of biomass, and is a form of charcoal. Biochar is defined by the International Biochar Initiative as the "solid material obtained from the thermochemical conversion of biomass in an oxygen-limited environment".
In the context of energy production, biomass is matter from recently living organisms which is used for bioenergy production. Examples include wood, wood residues, energy crops, agricultural residues including straw, and organic waste from industry and households. Wood and wood residues is the largest biomass energy source today. Wood can be used as a fuel directly or processed into pellet fuel or other forms of fuels. Other plants can also be used as fuel, for instance maize, switchgrass, miscanthus and bamboo. The main waste feedstocks are wood waste, agricultural waste, municipal solid waste, and manufacturing waste. Upgrading raw biomass to higher grade fuels can be achieved by different methods, broadly classified as thermal, chemical, or biochemical.
Miscanthus × giganteus, also known as the giant miscanthus, is a sterile hybrid of Miscanthus sinensis and Miscanthus sacchariflorus. It is a perennial grass with bamboo-like stems that can grow to heights of 3–4 metres (13 ft) in one season. Just like Pennisetum purpureum, Arundo donax and Saccharum ravennae, it is also called elephant grass.
Short rotation coppice (SRC) is coppice grown as an energy crop. This woody solid biomass can be used in applications such as district heating, electric power generating stations, alone or in combination with other fuels. Currently, the leading countries in area planted for energy generation are Sweden and the UK.
Second-generation biofuels, also known as advanced biofuels, are fuels that can be manufactured from various types of non-food biomass. Biomass in this context means plant materials and animal waste used especially as a source of fuel.
China has set the goal of attaining one percent of its renewable energy generation through bioenergy in 2020.
Sustainable biofuel is biofuel produced in a sustainable manner. It is not based on petroleum or other fossil fuels. It includes not using plants that are used for food stuff to produce the fuel thus disrupting the world's food supply.
Issues relating to biofuel are social, economic, environmental and technical problems that may arise from biofuel production and use. Social and economic issues include the "food vs fuel" debate and the need to develop responsible policies and economic instruments to ensure sustainable biofuel production. Farming for biofuels feedstock can be detrimental to the environment if not done sustainably. Environmental concerns include deforestation, biodiversity loss and soil erosion as a result of land clearing for biofuels agriculture. While biofuels can contribute to reduction in global carbon emissions, indirect land use change for biofuel production can have the inverse effect. Technical issues include possible modifications necessary to run the engine on biofuel, as well as energy balance and efficiency.
The Louisiana State University Agricultural Center, or the LSU AgCenter, is an agriculture research center associated with the Louisiana State University System and headquartered in Baton Rouge, Louisiana. The center conducts agricultural-based research through its Louisiana Agricultural Experiment Station and extends the knowledge derived from research to the people of the state of Louisiana through its Louisiana Cooperative Extension Service. The LSU AgCenter, one of 11 institutions within the Louisiana State University System, shares physical facilities with the LSU A&M campus.
Bioenergy forms a small part of the Turkish energy sector. There is unrealised potential to generate bioenergy using waste from the country's vast agricultural sector and forest resources. The possibility of expanding biogas, biofuel and bioethanol production and use has been suggested to supplement Turkey's energy needs, reduce dependency on fossil fuel imports and cut greenhouse gas emissions.