Energy production from forages (or American agriculture-back to the future)

At the turn of the century, with the exception of trains and water transportation, the transportation and agriculture industries of the U.S. were powered largely by herbaceous biomass. The herbaceous biomass was converted to usable energy by draft animals, primarily horses and mules. After 1900, automobiles, trucks, and tractors began to be used in transportation and agriculture. However, in 1920 there were still 25 million horses and mules on farms and ranches and 2 million draft animals in the cities of the United States (Ensminger 1955; (census of Agriculture 1920). The energy requirements of these animals were considerable. In the midwest, the feed requirements for a work horse during the six month crop growing season were 5,200 Ibs of roughage (hay or herbaceous biomass), 3,200 lbs of concentrate, usually oats, and pasture (Williams and Speelman 1934). Horses were an important source of power during and immediately after World War II. By 1954, U.S. agriculture and industry was largely powered by gasoline, diesel, or electrical motors and there were only 5 million horses and mules in the U.S (Census of Agriculture 1954). The decrease in the numbers of draft animals released approximately 80 million acres of land for other purposes (Census of Agriculture 1954)

Comparison of Two Perennial Grass Breeding Systems with Switchgrass

Two breeding systems, between- and withinfamily selection (BWFS) and multistep family selection (MFS), were compared using three switchgrass (Panicum virgatum L.) populations to determine which system was the most effective in improving biomass yield and in vitro dry matter digestibility (IVDMD). With BWFS, half-sib families are produced and evaluated on a family basis and then the best plants within the best families are selected for crossing to produce a new strain. With MFS, parent genotypes of the half-sib families being evaluated in the BWFS selection nursery are maintained and the genotypes whose progeny were the best in the BWFS evaluation trial are selected and polycrossed to produce a new strain. Methods were compared using two populations in which improved biomass yield and IVDMD were the selected traits and with a population for which improved IVDMD and winter survival were the selected traits. For the populations for which yield was a selection criteria, the BWFS breeding system produced strains with significantly greater biomass yields than the MFS system. For one of these populations, the BWFS and MFS systems did not differ for IVDMD but the MFS system produced a strain with higher IVDMD for the other population. For the population in which IVDMD and winter survival were the selection criteria, the BWFS strain had greater IVDMD than the MFS strain. Overall, the BWFS system was superior and required less work

Improving Warm-Season Forage Grasses Using Selection, Breeding, and Biotechnology

Plant breeding is human-directed evolution. Plant breeders manipulate the genetic resources of a species, i.e., its germplasm, to produce plants that are of increased value to humanity. Although humans have successfully manipulated the genetic resources of plants and animals for several thousand years, the science of genetics was not developed until this century. Breeding work on most forage grasses in the USA did not began until the 1930s and initial work was focused on developing strains that had good establishment capability, persistence, high forage and seed yields, and good insect and disease resistance. These are essential attributes of forages (Burton, 1986). This initial breeding work resulted in the development of grasses such as \u27Coastal\u27 bermudagrass (Cynodon dactylon L.), \u27Lincoln\u27 smooth bromegrass (Bromus inennis Leyss.), and \u27Kentucky 31\u27 tall fescue (Festuca arundinacea Schreb.) (Vogel & Sieper, 1994). Limited animal evaluation was involved in the development of these cultivars. The initial breeding work on warm-season native grasses also began in the mid 1930s as a result of efforts to reseed land damaged by erosion, i.e., the dust bowl, in the Great Plains of the USA

Switchgrass

Switchgrass (Panicum virgatum L.) is an erect, warm-season perennial whose native habitat originally included the prairies, open woods, brackish marches, and pinewoods (Pinus spp.) of most of North America except for the areas west of the Rocky Mountains and north of 55°N lat. (Hitchcock, 1951; Stubbendieck et aI., 1991). It is a polymorphic species with two distinct ecotypes, lowland and upland (Brunken and Estes, 1975), and with two major ploidy levels, tetraploid and octaploid (Hopkins et al, 1996; Hultquist et aI., 1996, 1997). The ecotypes are cross-fertile when plants with the same ploidy level are intermated (Martinez et aI., 2001). Ecotypes and cytotypes of switchgrass are classified as a single species

Seeding Rates for Establishing Big Bluestem and Switchgrass with Preemergence Atrazine Applications

The purpose of this study was to determine seeding rates for establishing switchgrass (Panicum virgatum L.) and debearded big bluestem (Andropogon gerardii Vitman) when atrazine [6-chloro-N-ethyl-N-(1-methylethyl)-l,3,5-triazine-2,4-diamine] is used as a preemergence herbicide. The high seed cost of these grasses makes it uneconomical to use higher seeding rates than necessary. The study was conducted on four eastern Nebraska sites during the period 1981 to 1985. The experimental design was a randomized complete block with six replications. Treatments were grasses (big bluestem and switchgrass) and seeding rates [107, 215, 325, and 430 pure live seeds (PLS) m-2] in a factorial arrangement. Plots were seeded in late spring with a plot seeder with double disk openers on a clean, firm seedbed, and broadcast sprayed with 2.2 or 3.0 kg ha-1 atrazine the day after seeding. Stands and forage yields were measured the first (Year 1) and second year (Year 2) following establishment. The 107 PLS m-2 seeding rate resulted in thinner, but still acceptable, stands (10-20 plants m-2) than the higher seeding rates in Year 1 and at two of the sites in Year 2. The stands from the higher rates, in general, did not differ within a site and were good to excellent (\u3e20 plants nv-2). The lowest seeding rate produced lower forage yields than the other rates in Year 1, but these differences were significant at only one site. There were no differences for Year 1 yield for the other rates or for Year 2 yields for all rates

4 Humans, Climate, and Plants: the Migration of Crested Wheatgrass and Smooth Bromegrass to the Great Plains of North America

The cultivation practices that were used in Europe and the eastern half of North America were utilized in the initial settlement of the Great Plains. Unfamiliarity with the climate of the Great Plains and Midwest and insufficient knowledge and technology to adapt crop production systems to the soils and climate lead to a major agriculture disaster which resulted in millions of hectares of land that needed to be re-seeded to grasses. Unrestricted grazing on public lands in the intermountain west resulted in severe rangeland degradation. Lack of knowledge and technology for using native plants and some specific characteristics of native plants that made them difficult to use resulted in the use of crested wheatgrasses and smooth bromegrass which had characteristics that met specific revegetation and production requirements. Crested wheatgrass and smooth bromegrass plant materials were from regions that were climatic analogs of the Great Plains and were adapted. These two grasses literally preserved the remaining top soil on millions of hectares of land. In the subsequent half-century, agronomist, geneticists, and rangeland scientists have learned how to establish and manage native grasses such as switchgrass (Panicum virgatum L.), big bluestem (Andropogon gerardii Vitman), indiangrass [Sorghastrum nutans (L.) Nash] and others so they are now available for use in revegetation. Although native grasses are available for use in the Great Plains and the Midwest of North America, crested wheatgrass and smooth bromegrass are now naturalized North American species and will continue to be vital to the economy of the USA and Canada. Their forage production patterns fits gaps in the forage production cycle for ruminant livestock that cannot be adequately met by native species in regions where bromegrass and crested wheatgrasses are well adapted

The Challenge: High Quality Seed of Native Plants to Ensure Successful Establishment

Native species are planted to re-vegetate former cropland, degraded pastures and rangelands, mined lands, natural areas, roadside right-of-ways, and other land management areas with plants, usually perennials, to stabilize and provide desirable classes of vegetation. Acceptable stands need to be obtained in a reasonable time. Seed of native plants varies widely in seed quality factors including seed size, purity, dormancy, germination, and vigor. Seed quality tests required for sale of native seeds usually include germination, purity, and hard or dormant seeds. These laboratory tests do not always predict the capability of a seed lot to establish a stand under field conditions and do not give the end user enough information to determine planting rate. The number of emerged seedlings per gram of seed in species specific stress tests may be a method of quantifying seed quality that is predictive of the seeds capability of producing a stand under field conditions. A standardized establishment test based on a unit of weight could be used to directly calculate planting rates

A Simple Method of Converting Rangeland Drills to Experimental Plot Seeders

Rangeland drills can be converted to experimental plot drills by mounting a cone seeder and a spinner divider over the seed box. The alne seeder feeds a uniform amount of seed over the length of a plot and the spinner divider splits the seed into fractions with each fraction going to a merent planting unit of the drill. Only one packet containing the amount of pure live seed to plant a plot is needed. Converted drills are self-cleaning. Numerous forage species can he seeded in contiguous plots without modifying or recalibrating the planter

Forage Yield and Quality of Tall Wheatgrass Accessions in the USDA Germplasm Collection

Tall wheatgrass [Thinopyrum ponticum (Podp.) Liu and Wang] is a cool-season bunchgrass from southern Europe and Asia Minor that is tolerant to saline or alkaline soils. The genetic base of tall wheatgrass cultivars is narrow. The lineages of four of the six cultivars of tall wheatgrass developed and released in the USA and Canada trace to a common accession, PI 98526. The objective of this study was to determine the extent of variation in the USDA collection of tall wheatgrass for forage quality, yield, and other agronomic traits. All available accessions of tall wheatgrass (n = 50) from the USDA Western Regional Plant Introduction Station at Pullman, WA, and two check cultivars, Platte and Jose, were used in the study. Greenhouse grown seedlings were transplanted in 1989 into a replicated field evaluation nursery located about 35 km west of Omaha, NE. An evaluation plot consisted of a single row of 10 plants spaced on 1.1-m centers. The experimental design was a blocks-in-replicates design with two replications. The plots were evaluated for forage yield and quality including in vitro dry matter digestibility (IVDMD), protein content, and other traits in 1990 and 1991. Several of the PI lines had forage yields equivalent to the check cultivars. One accession, PI 98526, had higher first harvest IVDMD than the check cultivars; other accessions had IVDMD values equivalent to the check cultivars. In addition to having high yields and high IVDMD, these accessions also were equivalent to the check cultivars in other agronomic traits as indicated by high leafiness and inflorescence scores. The results indicate that superior germplasm exists in the USDA tall wheatgrass germplasm collection that can be used to develop improved cultivars of tall wheatgrass with improved forage quality as measured by IVDMD

History of Grass Breeding for Grazing Lands in the Northern Great Plains of the USA and Canada

• In the early 1930s there were millions of acres of extensively degraded grazing lands and abandoned and eroded cropland in the Northern Plains of the United States and Canada. • Grass breeding and plant materials programs were established by both the US and Canadian governments and cooperating universities to develop revegetation materials. • Efforts of a small number of research locations and people resulted in grass cultivars or varieties that were used to revegetate and preserve the soil on millions of acres of land. • This is a brief history of the people, agencies, and universities that developed these cultivars that restored and increased the productivity of grasslands in the Northern Plains