1960; Walton, 1975; Carr et al., 1998; Chapko et al., 1991). Robinson (1960) reported that pea improved oat (Avena Intercropping barley (Hordeum vulgare L.) with Austrian winter sativa L.) forage yield. In a 2-yr pea-barley and pea-oat pea (Pisum sativum ssp. arvense L. Poir) may increase the use efficienintercropping study, Carr et al. (1998) found that total cies of growth resources and reduce fertilizer N requirements. The forage yield was unaffected by intercropping when the objectives of this study were to determine (i) row configuration and (ii) fertilizer N effects on yield, protein content, and the land equiva-cereal crop was sown at a rate equal to or greater than lent ratio (LER) of barley-pea intercropping systems. A 3-yr barleythe sole crop seeding rate. However, less forage was pea intercropping study was conducted at the Western and Central produced when the cereal component was sown at half Agricultural Research Centers (WARC and CARC) of Montana State the sole crop seeding rate. They also found that the University from 2000 to 2002 with three row configurations (4 rows intercropping forage yield was unaffected by the pea barley ϫ 4 rows pea, 2 rows barley ϫ 2 rows pea, and barley-pea mixed seeding rate. In other studies, forage and grain yield of within rows) and three N application treatments (0, 67, and 134 kg legumes were suppressed by cereal components (Ofori N ha Ϫ1 ). Barley biomass production increased 41% at WARC and and Stern, 1987; Hauggaard-Nielsen and Jensen, 2001; CARC, whereas pea biomass production decreased 34% at WARC Hauggaard-Nielsen et al., 2001). Seeding rates for comand 46% at CARC with the row configuration changing from the 4 ϫ 4 ponent crops in cereal-pea mixtures are commonly less to the mixed configuration. The LER ranged from 1.05 to 1.24 on a biomass basis and from 1.05 to 1.26 on a protein basis, indicating a than when either the cereal crop or pea is sown alone production advantage of intercropping. Barley is a more competitive (Carter and Larson, 1964; Droushiotis, 1989). component than pea. Separated row arrangements are advantageous The efficiency of an intercropping system can be evalwhere the desired outcome is a greater pea component in the harvested uated by the land equivalent ratio (LER), defined as forage, but the mixed arrangement has a greater total biomass yield the total area required under sole cropping to produce and LER. Fertilizer N increased total biomass yield and protein level the equivalent yields obtained under intercropping (De in barley-pea intercrops, but high N rates could decrease the LER Wit and Van Den Bergh, 1965; Willey, 1979; Mohta and and result in toxic levels of nitrate in the forage. De, 1980). It is expressed as:

Production of bioethanol from agricultural residues and hays (wheat, barley, and triticale straws, and barley, triticale, pearl millet, and sweet sorghum hays) through a series of chemical pretreatment, enzymatic hydrolysis, and fermentation processes was investigated in this study. Composition analysis suggested that the agricultural straws and hays studied contained approximately 28.62-38.58% glucan, 11.19-20.78% xylan, and 22.01-27.57% lignin, making them good candidates for bioethanol production. Chemical pretreatment with sulfuric acid or sodium hydroxide at concentrations of 0.5, 1.0, and 2.0% indicated that concentration and treatment agent play a significant role during pretreatment. After 2.0% sulfuric acid pretreatment at 121°C/15 psi for 60 min, 78.10-81.27% of the xylan in untreated feedstocks was solubilized, while 75.09-84.52% of the lignin was reduced after 2.0% sodium hydroxide pretreatment under similar conditions. Enzymatic hydrolysis of chemically pretreated (2.0% NaOH or H 2 SO 4 ) solids with Celluclast 1.5 LNovozym 188 (cellobiase) enzyme combination resulted in equal or higher glucan and xylan conversion than with Spezyme® CP-xylanase combination. The glucan and xylan conversions during hydrolysis with Celluclast 1.5 L-cellobiase at 40 FPU/g glucan were 78.09 to 100.36% and 74.03 to 84.89%, respectively. Increasing the enzyme loading from 40 to 60 FPU/g glucan did not significantly increase sugar yield. The ethanol yield after fermentation of the hydrolyzate from different feedstocks with Saccharomyces cerevisiae ranged from 0.27 to 0.34 g/g glucose or 52.00-65.82% of the theoretical maximum ethanol yield.

Row spacing, plant density, and N application timing can be manipulated to optimize plant growth and spatial distribution, therefore maximizing sunlight, nutrients, soil water use effi ciency and grain yield. A 2-yr fi eld study to evaluate the eff ects of four seeding rates (108, 215, 323, and 430 seeds m -2 ), two row spacings (15 and 30 cm), and three N treatments (FA1, 100% at seeding; FA2, 50% at seeding and 50% at tiller formation; and FA3, 50% at seeding and 50% at shoot elongation) on grain yield of McNeal hard red spring wheat (Triticum aestivum L.) was conducted in central Montana. Spring wheat accumulated greater biomass at a faster rate under the 15-cm row spacing than the 30-cm row spacing. Grain yield was 410 and 412 kg ha -1 greater at 15-cm than at 30-cm row spacings in 2004 and 2005, and the yield increase was primarily attributed to 44 and 40 more spikes m -2 at 15-cm than at 30-cm row spacing in 2004 and 2005, respectively. Grain yield was not signifi cantly aff ected by the N treatments, thus all N should be applied at seeding. Th e optimum seeding rate was 215 seeds m -2 . Tillers at higher seeding rates had larger phyllochrons and greater mortalities. Low protein content was found in FA3 and high seeding rate treatments in 2005. Narrow row spacing is recommended for high spring wheat yield in the northern Great Plains. Th is yield increase cannot be achieved by increasing seeding rate at wide row spacing.

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small-scale and short-term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock yield for each of the herbaceous species evaluated. The Feedstock Partnership expands our previous understanding of the bioenergy potential of switchgrass, Miscanthus, sorghum, energycane, and prairie mixtures on Conservation Reserve Program land by conducting long-term, replicated trials of each species at diverse environments in the U.S. Trials were initiated between 2008 and 2010 and completed between 2012 and 2015 depending on species. Field-scale plots were utilized for switchgrass and Conservation Reserve Program trials to use traditional agricultural machinery. This is important as we know that the smaller scale studies often overestimated yield potential of some of these species. Insufficient vegetative propagules of energycane and Miscanthus prohibited farm-scale trials of these species. The Feedstock Partnership studies also confirmed that environmental differences across years and across sites had a large impact on biomass production. Nitrogen application had variable effects across feedstocks, but some nitrogen fertilizer generally had a positive effect. National yield potential maps were developed using PRISM-ELM for each species in the Feedstock Partnership. This manuscript, with the accompanying supplemental data, will be useful in making decisions about feedstock selection as well as agronomic practices across a wide region of the country.

Winter pea (Pisum sativum L.) and lentil (Lens culinaris Medik.) have potential agronomic advantages over spring types in the Pacific Northwest (PNW) and northern Great Plains (NGP). The objectives of this study were to: (i) determine suitable seeding date and cereal stubble height in no‐till systems for winter pea and lentil; (ii) quantify and compare biomass and seed yield of winter pea and lentil with spring types; and (iii) compare adaptation of winter pea and lentil between the PNW and the NGP. Two breeding lines each of winter pea (PS9430706 and PS9530726) and winter lentil [LC9979010 (‘Morton’) and LC9976079] and two commercial cultivars each of spring pea (CDC Mozart and Delta) and spring lentil (Brewer and CDC Richlea) were sown on different dates (early and late fall dates for winter lines and spring date only for spring cultivars) and into different stubble heights (0.1 and 0.3 m) and compared for yield and agronomic adaptation in no‐till systems at four locations: Moccasin and Amsterdam, MT; Genesee, ID; and Rosalia, WA. Stubble height did not influence winter or spring pea biomass production or seed yield. Tall stubble increased lentil biomass by 220 to 530 kg ha−1 and seed yield by 100 to 260 kg ha−1 in five out of nine site–years. Fall‐seeded winter pea lines produced as much as 1830 kg ha−1 more seed yield than spring cultivars at the PNW sites, but not at the NGP sites. Early fall‐seeded lentil yielded as much as 480 and 590 kg ha−1 greater than spring types in the NGP and PNW, respectively. Delayed fall seeding and reduced stubble height decreased yields more frequently in the NGP than in the PNW.

found a regression relationship between canola seed yield and precipitation from 21 June to 20 August and Canola (Brassica napus L.) yield is often limited by heat and water mean daily temperature from 15 June to 15 August. The stress. Early seeding may avoid the heat and water stress at critical regression equations indicated that for each millimeter growth stages but will encounter low soil temperatures and frequent increase in precipitation, the yield of canola increased frosts. Three experiments were performed at two locations in Montana by 5.9 kg ha Ϫ1 . Also, for each degree rise in mean daily from 2002 to 2004 to determine (i) early spring seeding effect on seed temperature, there was a corresponding yield reduction yield and oil content and optimum seeding rates for early seeding, (ii) base temperature (T b ) for germination and heat requirement for of 188 kg ha Ϫ1 . In dryland cropping systems, water is emergence, and (iii) suitable cultivars for early spring seeding. Late-the most limiting factor for crop production. In a review March-seeded canola yielded 0 to 5% greater than mid-April seeding. paper, Johnston et al. (2002) suggested that a minimumDelaying seeding from mid-April to mid-May resulted in 43 to 63% of 127 mm of water is required for canola seed producyield reduction. Oil content was 12 to 22 g kg Ϫ1 greater for mid-May tion in the northern Great Plains. After the minimum seeding than mid-April seeding in 3 out of 5 site-year combinations.water requirement is met, canola produces 6.9 to 7.2 A seeding rate of 32 to 65 seeds m Ϫ2 was found sufficient to produce kg ha Ϫ1 of seed for every millimeter of precipitation optimum yields. Oil content tended to decrease 10 to 20 g kg Ϫ1 when consumed. Canola has a tap root system that can extract seeding rate increased from 11 to 97 seeds m Ϫ2 . The T b for germination water from a soil depth of 1.1 to 1.7 m (Nielsen, 1997). In was less than 4؇C, and the growing degree days for 50% emergence shallow soils that have a limited water-holding capacity, (GDD 50 ) were 42 to 81. Yield was negatively correlated (r ϭ Ϫ0.46 such as the Judith clay loam (fine-loamy, carbonatic to Ϫ0.65) to the days to 50% flowering, and biomass measured at Typic Calciborolls) in central Montana, canola may have 60 d after planting was negatively correlated to the chlorophyll fluores-to rely on frequent rainfall to sustain growth and procence ratio (F v /F m ) after cold stress (r ϭ Ϫ0.58). The optimal seeding duce seed during the latter part of the growing season.period for the region is between late March and mid-April. Several genotypes were found to have favorable characteristics for early Precipitation timing and amount vary greatly year to seeding.year and location to location in Montana. Consequently, growers in the region encounter highly unstable canola yields.

The potential of using ensiling, with and without supplemental enzymes, as a cost-effective pretreatment for bioethanol production from agricultural residues was investigated. Ensiling did not significantly affect the lignin content of barley straw, cotton stalk, and triticale hay ensiled without enzyme, but slightly increased the lignin content in triticale straw, wheat straw, and triticale hay ensiled with enzyme. The holocellulose (cellulose plus hemicellulose) losses in the feedstocks, as a result of ensiling, ranged from 1.31 to 9.93%. The percent holocellulose loss in hays during ensiling was lower than in straws and stalks. Ensiling of barley, triticale, wheat straws, and cotton stalk significantly increased the conversion of holocellulose to sugars during subsequent hydrolysis with two enzyme combinations. Enzymatic hydrolysis of ensiled and untreated feedstocks by Celluclast 1.5 L-Novozyme 188 enzyme combination resulted in equal or higher saccharification than with Spezyme CP-xylanase combination. Enzyme loadings of 40 and 60 FPU/g reducing sugars gave similar sugar yields. The percent saccharification with Celluclast 1.5 L-Novozyme 188 at 40 FPU/g reducing sugars was 17.1 to 43.6%, 22.4 to 46.9%, and 23.2 to 32.2% for untreated feedstocks, feedstocks ensiled with, and without enzymes, respectively. Fermentation of the hydrolysates from ensiled feedstocks resulted in ethanol yields ranging from 0.21 to 0.28 g/g reducing sugars.

Bulk optical characterization of dissolved organic matter from semiarid wheat-based cropping systems," Geoderma 306, (November 2017): 40-49. Made available through Montana State University's ScholarWorks scholarworks.montana.edu