1.     They should be carbon neutral and, preferably, carbon negative.
2.     They should have low–input production requirements.
3.     They should not compete with established food/feed systems and they should not compete for established food/feed cropland.
4.     They must have low water use requirements.
5.     They must be profitable to agriculture, the processing/conversion industry, and others.
6.     They must have desirable sociological impacts and characteristics.

Flux Farm's Biomass work is focused entirely on cropping systems that will work in the Intermountain West.

A significant portion of the irrigated acreage in the intermountain western U.S. is comprised of cool season grass pastures. Droughts, coupled with increasing demands for limited water supplies in the region, have decreased the water volumes available for irrigating these pastures and other crops. Consequently, relationship between crop yield and irrigation (water production functions) should be defined for various species and cultivars to help growers and water managers make appropriate selections based on water availability.

During a 3-year study on the Colorado Plateau, a line-source irrigation system was used to evaluate the relationship between applied water and dry forage production of orchardgrass (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), meadow brome (Bromus riparius Rehmann), smooth brome (Bromus inermis Leyss.), two cultivars of intermediate wheatgrass (Elytrigia intermedium [Host] Nevski), crested wheatgrass (Agropyron cristatum L. Gaertn. X desertorum [Fisch. ex Link] J.A. Schultes) and perennial ryegrass (Lolium perenne L.). Irrigation treatments, including precipitation, ranged from 457 to 970 mm in 1996, 427 to 754 mm in 1997 and 490 to 998 mm in 1998. There was a positive linear relationship between yield and irrigation for all cultivars when averaged over all years but the relationships varied between cultivars and years. Orchardgrass, meadow brome and tall fescue produced more dry forage than the other grasses at the highest irrigation levels in all years. These grasses also produced the greatest rates of yield increase per unit of irrigation (average of 0.0129 Mg ha−1 mm−1) and exhibited greater yield stability from year to year than the other grasses at irrigation levels above 700 mm. The intermediate wheatgrasses produced more forage than the other grasses under limited irrigation (less than 600 mm) but the average production rate with irrigation (0.0066 Mg ha−1 mm−1) was only about half that of the aforementioned grasses. The average rate of forage produced per mm of irrigation was intermediate in the smooth brome (0.0096 Mg ha−1) and lowest in the crested wheatgrass and perennial ryegrass (0.0048 and 0.0034 Mg ha−1, respectively). These results suggest that orchardgrass and meadow brome be included in irrigated pastures receiving more than 700 mm of water annually while the intermediate wheatgrasses be selected for pastures receiving an annual water application of less than 700 mm.  FIND ARTICLE HERE

Biofuels derived from low-input high-diversity (LIHD) mixtures of native grassland perennials can provide more usable energy, greater greenhouse gas reductions, and less agrichemical pollution per hectare than can corn grain ethanol or soybean biodiesel. High-diversity grasslands had increasingly higher bioenergy yields that were 238% greater than monoculture yields after a decade. LIHD biofuelsare carbon negative because net ecosystem carbon dioxide sequestration (4.4 megagram hectare–1year–1 of carbon dioxide in soil and roots) exceeds fossil carbon dioxide release during biofuel production (0.32 megagram hectare–1 year–1). Moreover, LIHD biofuels can be produced on agriculturally degraded lands and thus need to neither displace food production nor cause loss of biodiversity via habitat destruction.  FIND ARTICLE HERE

In this study an assessment is made of the future demand of fertilizers from bioenergy crop production. A representative sample of various assessments on the contribution of bioenergy is derived from literature. The projections are translated into fertilizer demand, assuming that all bioenergy is produced from dedicated woody bioenergy crops. The amount of nutrients in the harvested biomass is used as a proxy for the fertilizer demand. Results indicate that the global demand for fertilizer for bioenergy crop production is limited to 1% to 8% in 2015 and 2% to 16% in 2030 of the total global demand for fertilizers for agriculture (excluding bioenergy crop production), equal to 1 Mt, 12 Mt, 4 Mt and 26 Mt, respectively (sum of N, P2O5 and K2O). Particularly during the second quarter of the 21st century the production of bioenergy crops could increase rapidly, which could result in a fertilizer demand (sum of N, P2O5 and K2O) of 16 Mt to 63 Mt in 2050. The technical potential for bioenergy crop production are however much larger, comparable to a technical fertilizer demand in 2050 of 108 Mt to 640 Mt.  FIND ARTICLE HERE

Biomass currently supplies 3 percent of the total energy consumption in the United States, making it the largest source of domestic renewable energy. More than 50 percent of this biomass comes from wood residues and pulping liquors generated by the forest products industry. Biomass is particularly attractive because it is currently the only source of renewable transportation fuels (ethanol and biodiesel). To meet the U.S. Department of Energy's goal to achieve a 30 percent replacement of current domestic petroleum consumption by 2030, alterations in land use strategy will be needed.

This reports addresses the potential availability of biomass feedstock projected over the long term, emphasizing forest, agriculture, and urban derived biomass sources such as: dedicated fuel crops, animal manures and residues, municipal and urban wood residues, packaging materials, yard and tree trimmings, logging residues, crop residues, and perennially grown grasses and woody crops.

The following assumptions were made for the production of this report: all forested areas with out access to roads were excluded, all environmentally sensitive areas were excluded, equipment recovery limitations were considered, yields of corn, wheat and other grains were increased by 50%, the residue-to-grain ratio for soybeans was increased to 2:1, harvest technologies were capable of extracting 75% of crop residues, all crop land was managed with no-till methods, 55 million acres was dedicated to the production of perennial bioenergy crops, all excess manure residues were used for biofuel, all available residues were utilized.

If all of the assumptions were made, a total of 1.366 billion tons of biomass could be domestically produced (368 million tons from forest resources and 998 tons from agricultural resources) by 2030. As of 2005, a total of 190 million tons of biomass were produced domestically (142 million tons from forest resources and 48 million tons from agriculture resources).

Potential concerns and impacts of increased biomass production are also addressed, however little emphasis is placed on domestic food security.  FIND ARTICLE HERE

The total physical supply potential of biofuel feedstock from domestic municipal solid waste, forestry residues, crops residues and dedicated energy crops grown on existing cropland are estimated using optimistic assumptions about the promises of near-term conversion technologies. The production of between 30-100% of the 2003 gasoline demand can be met with liquid biofuels if changes in land use are made. The estimations are based on a computer model that maps interactions between the agriculture and energy sectors optimizing the cropland allocation of major crops with a pre-determined food security variable. The model indicates that increases in biofuel production will not adversely affect domestic food security, but will require livestock diets to be changed from hay and soymeal to whole corn or coproducts of biofuel processing (i.e. distillers grains).  FIND ARTICLE HERE

Increasing energy use, climate change, and carbon dioxide (CO2) emissions from fossil fuels make switching to low-carbon fuels a high priority. Biofuels are a potential low-carbon energy source, but whether biofuels offer carbon savings depends on how they are produced. Converting rainforests, peatlands, savannas, or grasslands to produce food crop–based biofuels in Brazil, Southeast Asia, and the United States creates a "biofuel carbon debt" by releasing 17 to 420 times more CO2 than the annual greenhouse gas (GHG) reductions that these biofuels would provide by displacing fossil fuels. In contrast, biofuels made from waste biomass or from biomass grown on degraded and abandoned agricultural lands planted with perennials incur little or no carbon debt and can offer immediate and sustained GHG advantages.  FIND ARTICLE HERE

This assessment estimates quantities of various biomass resources throughout the WGA region on a county or city basis for use as feedstocks for liquid fuel (transportation) production. The estimates are used to generate potential supply curves, calculate the effect of biomass and crop production on water use and carbon dioxide emissions, and provide quantities and supply curve data for an integrated GIS analysis. And finally, the assessment examines the impact that bioenergy crop production (grain and stover/straw) has on water use and carbon dioxide emissions due to irrigation and emissions of CO2 from crop planting/establishment, field maintenance, and harvesting.  FIND ARTICLE HERE

Treatment of municipal wastewater results worldwide in the production of large amounts of sewage sludge.  The major part of the dry matter content of this sludge consists of nontoxic organic compounds, in general a combination of primary sludge and secondary (microbiological) sludge. The sludge also contains a substantial amount of inorganic material and a small amount of toxic components.

There are many sludge-management options in which production of energy (heat, electricity, or biofuel) is one of the key treatment steps. The most important options are anaerobic digestion, co-digestion, incineration in combination with energy recovery, co- incineration in coal-fired power plants, co-incineration in combination with organic waste focused on energy recovery, use as an energy source in the production of cement or building materials, pyrolysis, gasification, supercritical (wet) oxidation, hydrolysis at high temperature, production of hydrogen, acetone, butanol, or ethanol, and direct generation of electrical energy by means of specific micro-organisms. Incineration and co- incineration with energy recovery and use of sewage sludge in the production of Portland cement are applied on a large scale. In these processes, the toxic organics are destructed and the heavy metals are immobilized in the ash or cement. The energy efficiency of these processes strongly depends upon the dewatering and drying step. It is expected that these applications will strongly increase in the future. Supercritical wet oxidation is a promising innovative technology but is still in the development stage.

With the exception of biogas production, the other biological methods to produce energy are still in the initial research phase. Production of biogas from sewage sludge is already applied worldwide on small, medium, and large scales. With this process, a substantial experience exists and it is expected that this application is getting more and more attention. Besides the increasing focus on the recovery and reuse of energy, inorganics, and phosphorous, there is also an increasing focus to solve completely the problem of the toxic organics and inorganic compounds in sludge. In the assessment and selection of options for energy recovery by means of biological methods, this aspect has to be taken into account.  FIND ARTICLE HERE

Warm-season grasses have shown great potential for biomass production. However, their productivity under irrigated conditions has not been thoroughly documented. This study evaluated the biomass production potential and production stability of a number of warm- and cool-season grasses across an irrigation gradient. Under the multiple-harvest management strategy, the cool-season grasses were most productive across the entire growing season. Nevertheless, when considering only the summer harvests, the switchgrass and big bluestem entries were the most productive, although the lowland cultivar Alamo did not perform well under the conditions. Overall, cool-season grasses were clearly the most productive for total biomass production across the growing season. However, based on the high biomass production of switchgrass, this species may have potential as a high-producing option for animal feed during the summer months when the cool-season grasses are unproductive.  FIND ARTICLE HERE

Establishment of Warm-Season Grasses in Summer and Damage in Winter Under Supplementary Irrigation in a Semi-Arid Environment at High Elevation in Western United States of America

As with other areas of the world, herbage production of cool-season grasses in irrigated semi-arid areas of the western USA at high elevation declines during summer. The use of warm-season grasses during this period could be a possible way to ameliorate this decline in herbage production. The ability of twenty-one grass cultivars, representing seven warm-season grass species, to establish in the summer of 2005, as measured by stand frequency and herbage production, the potential for damage in winter under irrigated conditions in 2005-2006 and the stand frequency in 2006 at two sites in semi-arid environments of the western USA was compared with that of a cultivar of each of six cool-season grass species. Some warm-season grass species, including switchgrass (Panicum virgatum), showed potential for use in this environment, based on their similar herbage production in 2005 and similar values of stand frequency in 2005 and 2006 to that of cool-season grasses. All the cultivars of the warm-season grass species suffered greater winter damage than did the cultivars of the cool-season species. The higher winter damage to the species of warm-season grasses did not correspond with a lower stand frequency in the second year.  FIND ARTICLE HERE

Many crop species will be required to meet goals for energy production from biomass and biofuels. Perennial grasses will be one of the more important categories of crops, partly due to high biomass yield potential, the native status of many species, and their potential to serve multiple functions that include soil and water conservation, wildlife habitat, and landscape diversification. In the USA, switchgrass (Panicum virgatum), big bluestem (Andropogon gerardii), bermudagrass (Cynodon dactylon), napiergrass (Pennisetum purpureum), eastern gamagrass (Tripsacum dactyloides), reed canarygrass (Phalaris arundinacea), and wildryes (Leymus triticoides and L. cinerus) are currently undergoing germplasm assemblage, pre-breeding, advanced breeding, and/or cultivar development efforts for bioenergy production. Switchgrass represents the most advanced of these species, largely because the US DOE chose switchgrass as its herbaceous model species in the early 1990s, supporting existing programs and creating new programs with funding infusions through 2002. The remainder of these breeding programs are just beginning or are developing as spin-offs from existing breeding programs aimed at the livestock industry. Breeding objectives for these species include, first-and-foremost, increased biomass yield, followed by increased stress tolerances, improved biomass quality (conversion efficiency), and other agronomic traits, depending on the species and region.  FIND ARTICLE HERE

Forage kochia (Kochia prostrata (L.) Schrad.), also known as prostrate kochia, or prostrate summer cypress is a long-lived, perennial, semi-evergreen, half-shrub well adapted to the temperate, semiarid and arid regions of central Asia and the western U.S. In these areas it has proven to be a valuable forage plant for sheep, goats, camels, cattle, and horses. Forage kochia is a C4 plant that is extremely drought and heat tolerant, in part due to a taproot that can extend up to 6.5m in depth. It is also very salt tolerant and well adapted to some ecosystems dominated by halophytic species. It has been reported to be very productive when grown in soils with salinity electrical conductivity (EC) levels approaching 20dS/m, and capable of persisting at much higher EC levels. Forage kochia's biomass yield depends upon the subspecies and environment, but reports generally range from 1000 to 1800kg/ha in environments receiving 100–200mm annual precipitation. Studies and practical experience have shown that forage kochia is very palatable and nutritious, especially during the late summer through winter period. Its nutritional characteristics include fall and winter crude protein levels above 70g/kg needed for gestating ruminants. It also has low tannins and oxalates, and has not been reported to be a nitrate accumulator. When fed alone, it has acceptable fiber qualities, but research has shown that it can improve digestion kinetics when in a mixed diet with the low quality grasses as is common during late summer, fall, and winter months. Overall, forage kochia has the potential to improve the sustainability of small ruminant production in semiarid regions that frequently experience extended drought and saline conditions.
FIND ARTICLE HERE

Interest in producing cellulosic ethanol from renewable energy sources is growing. Potential energy crops include row crops such as corn (Zea mays L.), perennial warm-season grasses (WSGs), and short-rotation woody crops (SRWCs). However, impacts of growing dedicated energy crops as biofuel on soil and environment have not been well documented. Th is article reviews the (i) impacts of growing WSGs and SRWCs on soil properties, soil organic carbon (SOC) sequestration, and water quality, and (ii) performance of energy crops in marginal lands. Literature shows that excessive (≥50%) crop residue removal adversely impacts soil and environmental quality as well as crop yields. Growing WSGs and SRWCs can be potential alternatives to crop residue removal as biofuel. Warm-season grasses and SRWCs can improve soil properties, reduce soil erosion, and sequester SOC. Crop residue removal reduces SOC concentration by 1 to 3 Mg ha−1 yr−1 in the top 10 cm, whereas growing WSGs and SRWCs increase SOC concentration while providing biofuel feedstocks. Th e WSGs can store SOC between 0 and 3 Mg C ha−1 yr−1 in the top 5 cm of soil, while the SRWCs can store between 0 and 1.6 Mg ha−1 yr−1 of SOC in the top 100 cm. Th e WSGs and SRWCs have more benefi cial eff ects on soil and environment when grown in marginal lands than when grown in croplands or natural forests. Indeed, they can grow in nutrient-depleted, compacted, poorly drained, acid, and eroded soils. Development of sustainable systems of WSGs and SRWCs in marginal lands is a high priority.  FIND ARTICLE HERE

Biofuels are a major topic of global interest and technology development. Whereas bioenergy crop production is highly dependent on water, bioenergy development requires effective allocation and management of water. The objectives of this investigation were to assess the bioenergy production relative to the impacts on water resource related factors: (1) climate and weather impact on water supplies for biomass production; (2) water use for major bioenergy crop production; and (3) potential alternatives to improve water supplies for bioenergy. Shifts to alternative bioenergy crops with greater water demand may produce unintended consequences for both water resources and energy feedstocks. Sugarcane and corn require 458 and 2036 m3 water/m3 ethanol produced, respectively. The water requirements for corn grain production to meet the US-DOE Billion-Ton Vision may increase approximately 6-fold from 8.6 to 50.1 km3. Furthermore, climate change is impacting water resources throughout the world. In the western US, runoff from snowmelt is occurring earlier altering the timing of water availability. Weather extremes, both drought and flooding, have occurred more frequently over the last 30 years than the previous 100 years. All of these weather events impact bioenergy crop production. These events may be partially mitigated by alternative water management systems that offer potential for more effective water use and conservation. A few potential alternatives include controlled drainage and new next-generation livestock waste treatment systems. Controlled drainage can increase water available to plants and simultaneously improve water quality. New livestock waste treatments systems offer the potential to utilize treated wastewater to produce bioenergy crops. New technologies for cellulosic biomass conversion via thermochemical conversion offer the potential for using more diverse feedstocks with dramatically reduced water requirements. The development of bioenergy feedstocks in the US and throughout the world should carefully consider water resource limitations and their critical connections to ecosystem integrity and sustainability of human food.  FIND ARTICLE HERE

An irrigated study was conducted at the Western Colorado Research Center at Fruita for 6 years to evaluate eight hybrid poplar clones under short-term, intensive culture. The eight clones included in the study were Populus nigra x P. maximowiczii (NM6), P. trichocarpa x P. deltoides (52225, OP367), and P. deltoides x P. nigra (Norway, Noreaster, Raverdaus, 14274, 14272). Data were collected for growth, aerial biomass yield, dry matter partitioning, carbon sequestration, and insect and disease infestation. OP367 and 52225 consistently had larger tree diameters than other hybrids for each of the 6 years. Averaged across clones, yield was 58.4 Mg ha−1. OP367 had the highest yield at 72.2 Mg ha−1 and 14274 had the lowest yield at 41.0 Mg ha−1. The yield of OP367 was 1.8 times greater than that of 14274. Carbon yield over the 6 years of testing was highest for OP367 at 33.4 Mg C ha−1 and lowest for 14274 at 18.8 Mg C ha−1. Of the eight clones tested, OP367 was the most adapted and productive clone in this short-term, intensive culture system in the arid environment of the Grand Valley of western Colorado as evidenced by its productive growth, yield, insect resistance, winterhardiness, and tree architecture. Several insect species infested the poplar clones over the course of the rotation. Best management practices for growers who produce hybrid poplar under short-term, intensive culture should include the following: (1) plant highly productive clones, (2) poplar clones with suitable tree architecture for production and market objectives should be used, (3) if carbon sequestration is an important production objective, plant a suitable clone, (4) some poplar clones develop chlorosis when planted in high pH soils and should be avoided, and (5) use poplar clones that have been shown to exhibit resistance to specific insect species.  FIND ARTICLE HERE

The rapid growth rates of hybrid poplar (Populus spp.) enable rotations of 3–6 years for biofuels or 10–15 years to obtain merchantable timber, but many clones are susceptible to nutrient deficiencies when grown in alkaline soils. A 1995 Oregon study demonstrated that clone OP-367 (P. deltoides × P. nigra) was the only clone tested that performed well on alkaline soils. Tests in Colorado and New Mexico confirmed the adaptation of this clone. A multi-clonal trial was established in 2003 at Farmington, New Mexico and Ontario, Oregon in order to screen a larger number of clones for adaptability to alkaline soils. Trees were planted at 1.5 × 1.5 m spacing and irrigated by surface drip irrigation. Diameter at breast height (DBH) and tree height were recorded annually (2003–2006); wood volumes (WVol) and total above ground biomass (TAB) were calculated from these measurements. Of the 25 clones tested, 19 were common to both sites. Mean height was greater at the Ontario site through the first 3 years (2003–2005). By the end of four seasons, the tallest Farmington entry was OP-367 at 9.4 m with 177 Mg ha−1 TAB while the tallest Ontario entry was Malheur-3 at 8.9 m with 195 Mg ha−1 TAB and several other clones had statistically similar production. Given the growth and productivity range at these two sites, it is difficult to make generalizations across wide areas, but it appears feasible to identify clones suited to alkaline soils in arid and semi-arid regions.  FIND ARTICLE HERE