Perennial grasses display many beneficial attributes as energy crops, and there has been increasing interest in their use in the US and Europe since the mid-1980s. In the US, the Herbaceous Energy Crops Research Program (HECP), funded by the US Department of Energy (DOE), was established in 1984. After evaluating 35 potential herbaceous crops of which 18 were perennial grasses it was concluded that switchgrass (Panicum virgatum) was the native perennial grass which showed the greatest potential. In 1991, the DOE's Bioenergy Feedstock Development Program (BFDP), which evolved from the HECP, decided to focus research on a “model” crop system and to concentrate research resources on switchgrass, in order to rapidly attain its maximal output as a biomass crop. In Europe, about 20 perennial grasses have been tested and four perennial rhizomatous grasses (PRG), namely miscanthus (Miscanthus spp.), reed canarygrass (Phalaris arundinacea), giant reed (Arundo donax) and switchgrass (Panicum virgatum) were chosen for more extensive research programs. Reed canarygrass and giant reed are grasses with the C3 photosynthetic pathway, and are native to Europe. Miscanthus, which originated in Southeast Asia, and switchgrass, native to North America, are both C4 grasses. These four grasses differ in their ecological/climatic demands, their yield potentials, biomass characteristics and crop management requirements. Efficient production of bioenergy from such perennial grasses requires the choice of the most appropriate grass species for the given ecological/climatic conditions. In temperate and warm regions, C4 grasses outyield C3 grasses due to their more efficient photosynthetic pathway. However, the further north perennial grasses are planted, the more likely cool season grasses are to yield more than warm season grasses. Low winter temperatures and short vegetation periods are major limits to the growth of C4 grasses in northern Europe. With increasing temperatures towards central and southern Europe, the productivity of C4 grasses and therefore their biomass yields and competitiveness increase.

Since breeding of and research on perennial rhizomatous grasses (PRG) is comparatively recent, there is still a significant need for further development. Some of the given limitations, like insufficient biomass quality or the need for adaption to certain ecological/climatic zones, may be overcome by breeding varieties especially for biomass production. Furthermore, sure and cost-effective establishment methods for some of the grasses, and effective crop production and harvest methods, have yet to be developed.

This review summarizes the experience with selecting perennial grasses for bioenergy production in both the US and Europe, and gives an overview of the characteristics and requirements of the four most investigated perennial rhizomatous grasses; switchgrass, miscanthus, reed canarygrass and giant reed.

The development and current status of perennial rhizomatous grasses as energy crops in the US and Europe

The Report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of “potential” biomass within the contiguous United States based on numerous assumptions about current and
future inventory and production capacity, availability, and technology. In the 2005 BTS, a strategic analysis was undertaken to determine if U.S. agriculture and forest resources have the capability to potentially produce at least one billion dry tons of biomass annually, in a sustainable manner—enough to displace approximately
30% of the country’s present petroleum consumption. To ensure reasonable confidence in the study results, an effort was made to use relatively conservative assumptions. However, for both agriculture and forestry, the resource potential was not restricted by price. That is, all identified biomass was potentially available, even though some potential feedstock would more than likely be too expensive to actually be economically available.
In addition to updating the 2005 study, this report attempts to address a number of its shortcomings

/pdf/u-s-billion-ton-update-biomass-supply-for-a-bioenergy-and-39t7zcevg2.pdf

U.S. Billion-ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry

This chapter offers a comprehensive survey of the economic analysis of advertising. A first objective is to organize the literature in a manner that clarifies what is known. A second objective is to clarify how this knowledge has been obtained. The chapter begins with a discussion of the key initial writings that are associated with the persuasive, informative and complementary views of advertising. Next, work that characterizes empirical regularities between advertising and other variables is considered. Much of this work is conducted at the inter-industry level but important industry studies are also discussed. The chapter then offers several sections that summarize formal economic theories of advertising. In particular, respective sections are devoted to positive and normative theories of monopoly advertising, theories of price and non-price advertising, theories of advertising and product quality, and theories that explore the potential role for advertising in deterring entry. At this point, the chapter considers the empirical support for the formal economic theories of advertising. A summary is provided of empirical work that evaluates the predictions of recent theories of advertising, including work that specifies and estimates explicitly structural models of firm and consumer conduct. This work is characterized by the use of industry (or brand) and even household-level data. The chapter then considers work on endogenous and exogenous sunk cost industries. At a methodological level, this work is integrative in nature: it develops new theory that delivers a few robust predictions, and it then explores the empirical relevance of these predictions at both inter-industry and industry levels. Finally, the chapter considers new directions and other topics. Here, recent work on advertising and media markets is discussed, and research on behavioral economics and neuroeconomics is also featured. A final section offers some concluding thoughts.

/pdf/the-economic-analysis-of-advertising-18bel9imim.pdf

The economic analysis of advertising

Switchgrass (Panicum virgatum L.)—a perennial, warm-season (C4) species—evolved across North America into multiple, divergent populations. The resulting natural variation within the species presents considerable morphological diversity and a wide range of adaptation. The species was adopted as a crop—initially as a forage—only in the last 50 yr. Its potential uses have recently been expanded to include biofuels. Management of switchgrass for biofuels is informed by an understanding of the plant's biology. Successful establishment requires attention to seed dormancy and weed control as well as proper depth and date of planting. The plant's growth rate is closely tied to temperature, but timing of reproductive development is linked to photoperiod. Accordingly, the period of vegetative growth can be extended by planting lower-latitude cultivars at higher latitudes. This strategy may provide a yield advantage, but cold tolerance can become limiting. Switchgrass is thrifty in its use of applied N; it appears a...

The Biology and Agronomy of Switchgrass for Biofuels

The adoption of agricultural innovations: A review

The competitive firm's response to risk

Herbaceous crops may be an important source of renewable energy. Production costs can be more competitive by increasing yields so that overhead costs are applied to more biomass. Most previous economic studies of energy crops have concentrated on the production of switchgrass (Panicum virgatum L.). This study analyzes the biomass yield and economic potential of several high-yielding annual and perennial crops on prime and marginal, sloping land. Crops evaluated were reed canarygrass (Phalaris arundinacea L.) harvested twice per year; switchgrass and big bluestem (Andropogon gerardii Vitman var. gerardii); alfalfa (Medicago sativa L.); and sweet sorghum, forage sorghum [both Sorghum bicolor (L.) Moench], and maize (Zea mays L.). The intercropping of the two sorghum species into reed canarygrass and alfalfa was also analyzed. All crops but alfalfa were fertilized with 0, 70, 140, or 280 kg N ha −1 , with economic analysis performed assuming 140 kg N ha −1 . Sorghums were most productive, with more than 16 t of dry matter ha−1. Switchgrass was the highest-yielding perennial crop. Costs per ton of biomass produced were lowest for sorghum, somewhat higher for switchgrass, higher still for big bluestem, and highest for alfalfa and reed canarygrass. Yields per ton for intercropped species were higher than for perennial species but lower than for monocrop sorghum. Costs per ton for intercropped species were less than for either alfalfa or reed canarygrass, but were higher than costs per ton of monocrop sorghum. Although the sorghums had the highest yields, high potential for erosion on sloping soils may preclude their use on these soils.

Comparative Economic Analysis of Perennial, Annual and Intercrops for Biomass Production

Comparative economic analysis of perennial, annual, and intercrops for biomass production ☆

Empirical studies of economies of size in agriculture have generally found the cost curve to be "L"-shaped. Changes in the structure of agriculture over time are not necessarily consistent with this cost structure. These differences can be reconciled by appeal to external, non-size factors, and to difficulties in correctly measuring size economies. In addition to size economies, important factors affecting the size structure of agriculture include pecuniary economies at the firm and industry level, technical change, management and information, values and goals, and opportunity costs outside the agricultural sector. Size economies may be incorrectly measured due to poor data, misspecified technologies, unrealistic assumptions, and aggregation error.

Arne Hallam

Papers

The competitive firm's response to risk

Comparative Economic Analysis of Perennial, Annual and Intercrops for Biomass Production

Comparative economic analysis of perennial, annual, and intercrops for biomass production ☆

Economies of Size and Scale in Agriculture: An Interpretive Review of Empirical Measurement

Commodity Costs and Returns Estimation Handbook: A Report of the Aaea Task Force on Commodity Costs and Returns