• Authors:
    • McCartney, D.
    • Fraser, J.
  • Source: Canadian Journal of Plant Science
  • Volume: 90
  • Issue: 4
  • Year: 2010
  • Summary: The need to reduce agricultural input costs while increasing soil fertility has prompted researchers to look for alternative crop production systems that include N fixing crops. Annual legumes can be used in rotations as forages and green manure crops to increase the organic matter and N content of soils and provide soil cover to control erosion and weeds. Despite the benefits of annual legumes, high production costs and scarcity of seed has hindered their use.
  • Authors:
    • Tabil, L. G.
    • Adapa, P. K.
    • Schoenau, G. J.
  • Source: Applied Engineering in Agriculture
  • Volume: 26
  • Issue: 4
  • Year: 2010
  • Summary: Compaction of low bulk density agricultural biomass is a critical and desirable operation for sustainable and economic availability of feedstock for biofuel industry. A comprehensive study of the compression characteristics (density of pellet and total specific energy required for compression) of ground non-treated and steam-exploded barley, canola, oat, and wheat straw obtained from three hammer mill screen sizes of 6.4, 3.2 and 1.6 mm at 10% moisture content (wb) was conducted. Four preset pressures of 31.6, 63.2, 94.7, and 138.9 MPa were applied using an Instron testing machine to compress samples in a cylindrical die. Ground steam-exploded barley straw at screen sizes of either 3.2 or 1.6 mm produced high density compacts, while ground steam-exploded canola, oat, and wheat straw at screen sizes of 6.4, 3.2 or 1.6 mm produced high density compacts. Steam-exploded barley straw for 3.2 mm at 138.9 MPa produced compacts having 13% higher density and consumed 19% lower total specific energy compared to non-treated straw. Steam-exploded canola straw for 1.6 mm at 138.9 MPa produced compacts having 13% higher density and consumed 22% higher total specific energy compared to non-treated straw. Steam-exploded oat straw for 3.2 mm at 94.7 MPa produced compacts having 19% higher density and consumed 13% higher total specific energy compared to non-treated straw. Steam-exploded wheat straw for 6.4 mm at 138.9 MPa produced compacts having 17% higher density and consumed 17% higher total specific energy compared to non-treated straw. Three compression models, namely: Jones model, Cooper-Eaton model, and Kawakita-Ludde model were considered to determine the pressure-volume and pressure-density relationship of non-treated and steam-exploded straws. Kawakita-Ludde model provided the best fit to the experimental data having R 2 values of 0.99 for non-treated straw and 1.00 for steam-exploded biomass samples. The steam-exploded straw had higher porosity than non-treated straw. In addition, the steam-exploded straw was easier to compress since it had lower yield strength or failure stress values compared to non-treated straw.
  • Authors:
    • Martz, L. W.
    • Pomeroy,J. W.
    • Armstrong, R. W.
  • Source: Canadian Water Resources Journal
  • Volume: 35
  • Issue: 2
  • Year: 2010
  • Summary: Physically-based atmospheric models of evapotranspiration (ET) that consider the Penman combination energy balance and aerodynamic approach have achieved acceptance as useful tools for obtaining estimates of actual ET from land surfaces. These models have been made applicable to the case of non-saturated conditions through either surface resistance formulations (e.g., Penman-Monteith) or by application of the complementary evaporation theory of feedback between the atmosphere and surface moisture states (e.g., Granger-Gray). Their application becomes complicated under conditions of drought, when extremely low soil moisture availability severely restricts ET from the soil and plants. Under such severe conditions, consideration for the surface water balance and interactions with the balance of available energy and aerodynamic principles are Important for accurately estimating actual ET A modelling application is demonstrated using the Cold Regions Hydrological Model (CRHM) platform to examine the estimation of ET under drought conditions. CRHM allows users to assemble hydrological models by linking a suite of modular physically-based algorithms that describe the individual processes. In this case, the models assembled consider infiltration, evaporation, and sod moisture accounting and are applied to a mixed prairie located at Lethbridge, Alberta, Canada under drought conditions during the growing period in 2000 and 2001. Near surface meteorological and ecological observations used as model input and for evaluating model performance were obtained through the Ameriflux network and the Agriculture and Agri-Food Canada (AFC) Lethbridge Research Centre Results show that consideration for the effective rooting zone depth of the mixed-prairie at the site is important for estimating actual ET using the Penman-Montieth and Granger-Gray models during severe moisture stress. Relative differences in ET estimates provided by the models are discussed in the context of their contrasting theoretical approaches.
  • Authors:
    • Haber, S. M.
    • Fetch, T. G.,Jr.
    • Chong, J.
    • Ames, N.
    • Duguid, S. D.
    • Brown, P. D.
    • Fetch, J. W. M.
    • Menzies, J. G.
    • Stadnyk, K. D.
  • Source: Canadian Journal of Plant Science
  • Volume: 89
  • Issue: 1
  • Year: 2009
  • Summary: Jordan is a high-yielding, white-hulled spring oat ( Avena sativa L.) cultivar postulated to carry the crown rust resistance combination Pc38, Pc39, and Pc68, which was effective against the prevalent pathotypes of crown rust races on the Canadian prairies at the time of its release. It has very good resistance to loose and covered smut, moderately good resistance to most of the prairie stem rust races (likely due to the presence of Pg2 and Pg13) and moderate tolerance to barley yellow dwarf virus (BYDV). Jordan has high kernel weight, high percent plump kernels, and low percent thin kernels. Jordan exhibits high yielding capacity in the oat growing areas of western Canada. Jordan was supported for registration at the Prairie Grain Development Committee Meeting in February 2005.
  • Authors:
    • Menzies, J. G.
    • Fetch, T. G.
    • Clayton, G. W.
    • Chong, J.
    • Kibite, S.
    • Fetch, J. W. M.
    • Turkington, T. K.
  • Source: Canadian Journal of Plant Science
  • Volume: 89
  • Issue: 4
  • Year: 2009
  • Summary: Lee Williams is a high-yielding hulless oat ( Avena sativa L.) with good disease resistance and good straw strength. It is well adapted to all of the oat producing regions of western Canada. It carries genetic resistance to several races of crown rust (caused by Puccinia coronata Corda f. sp. avenea Eriks.) and stem rust (caused by P. graminis f. sp. avenae Pers.), loose [ Ustilago avenae (Pers.) Rostr.], and covered smut ( U. kolleri Wille), and moderate resistance to barley yellow dwarf virus (BYDV). Lee Williams has protein and oil levels and a high groat to hull ratio that make it well-suited for livestock feed. Hulless oat may retain a low percentage of hulls after threshing so a high groat to hull ratio is desirable. Lee Williams was supported for registration at the Prairie Regional Recommending Committee for Grains meeting in February 2002.
  • Authors:
    • Mann, D.
    • Ranjan, R.
    • Kahimba, F.
  • Source: Applied Engineering in Agriculture
  • Volume: 25
  • Issue: 6
  • Year: 2009
  • Summary: Soil freezing and thawing processes and soil moisture redistribution play a critical role in the hydrology and microclimate of seasonally frozen agricultural soils. Accurate simulations of the depth and timing of frost and the redistribution of soil water are important for planning farm operations and choosing rotational crops. The Simultaneous Heat and Water (SHAW) model was used to predict soil temperature, frost depth, and soil moisture in agricultural soils near Carman, Manitoba. The model simulations were compared with three years of field data collected from summer 2005 to the summer 2007 in four cropping system treatments (oats with berseem clover cover crop, oats alone, canola, and fallow). The simulated soil temperatures compared well with the measured data in all the seasons (R 2=0.96-0.99). The soil moisture simulations were better during the summer (RMSE=9.1-12.0% of the mean) compared to the winter seasons (RMSE=17.5-19.7% of the mean). During the winter, SHAW over-predicted by 0.02 to 0.10 m 3 m -3 the amount of total soil moisture below the freeze front and under-predicted by 0.02 to 0.05 m 3 m -3 the soil moisture in the upper frozen layers. The model was revised to account for the reduction in effective pore space resulting from frozen water to improve the winter soil moisture predictions. After this revision, the model performed well during the winter (RMSE=14.4% vs. 17.5%; R 2=0.74 vs. 0.67 in vegetated treatments, and RMSE=12.9% vs. 19.7%; R 2=0.73 vs. 0.52 in fallow treatments). The modified SHAW model is an enhanced tool for predicting the soil moisture status as a function of depth during spring thawing, and for assessing the availability of soil moisture at the beginning of the subsequent growing season.
  • Authors:
    • Lafond, G.
    • Gan, Y.
    • Brandt, S.
    • McConkey, B.
    • Cutforth, H.
    • Angadi, S.
    • Judiesch, D.
  • Source: Canadian Journal of Plant Science
  • Volume: 89
  • Issue: 3
  • Year: 2009
  • Summary: Canola is a viable crop when grown under fallow in the semiarid prairie, but is also grown in longer rotations, most often no-till seeded into standing stubble. Selecting the proper N fertilizer rate is a very challenging production decision, but most of the available nitrogen response for canola has been derived for the more subhumid parts of the Canadian prairies. We developed simple quadratic equations to describe the yield relationship for stubble-seeded open-pollinated and hybrid canola in the semiarid Canadian prairie. These relationships indicate that hybrid canola produced higher grain yields at all fertilizer rates and had optimum N fertilizer rates about 50% higher than those for open-pollinated canola.
  • Authors:
    • Basnyat, P.
    • Liu, P.
    • Lemke, R.
    • Janzen, H.
    • Campbell, A.
    • Gan, T.
    • McDonald, C. L.
  • Source: Canadian Journal of Plant Science
  • Volume: 89
  • Issue: 5
  • Year: 2009
  • Summary: Crop roots transport water and nutrients to the plants, produce nutrients when they decompose in soil, and provide organic C to facilitate the process of C sequestration in the soil. Many studies on these subjects have been published for cereal crops, but little is known for oilseed and pulse crops. This study was conducted at Swift Current, Saskatchewan, in 2006 and 2007 to characterize the root growth and distribution profile in soil for selected oilseed and pulse crops. Three oilseed [canola ( Brassica napus L.), mustard ( Brassica juncea L.), flax ( Linum usitatissimum L.)], three pulse crops [chickpea ( Cicer arietinum L), dry pea ( Pisum sativum L.) lentil ( Lens culinaris Medik.)], and spring wheat ( Triticum aestivum L.) were grown in 100 cm deep * 15 cm diameter lysimeters pushed into a silt loam soil. Crops were studied under rainfed and irrigated conditions. Lysimeters were removed from the field and sampled for above-ground (AG) and root mass at different depths at five growth stages. Root mass was highest for canola (1470 kg ha -1) and wheat (1311 kg ha -1), followed by mustard (893 kg ha -1) and chickpea (848 kg ha -1), and was lowest for dry pea (524 kg ha -1) and flax (440 kg ha -1). The root mass of oilseeds and pulses reached a maximum between late-flowering and late-pod stages and then decreased to maturity, while wheat root mass decreased to maturity after reaching a maximum at boot stage. On average, about 77 to 85% of the root mass was located in the 0-40 cm depth. Canola, mustard, and wheat rooted to 100 cm, while the pulses and flax had only 4 to 7% of the root mass beyond the 60 cm depth. Irrigation only increased root mass in the 0-20 cm depth. Roots developed more rapidly than AG biomass initially, but the ratio of root biomass to AG biomass decreased with plant maturity. At maturity, the ratio of root biomass to AG biomass was 0.11 for dry pea, and between 0.20 and 0.22 for the other crops tested. Our findings on rooting depths and root mass distribution in the soil profile should be useful for modelling water and nutrient uptake by crops, estimating C inputs into soil from roots, and developing diverse cropping systems with cereals, oilseeds and pulses for semiarid environments.
  • Authors:
    • Wang, H.
    • Schoenau, J. J.
    • Brandt, S.
    • Lafond, G.
    • Malhi, S. S.
    • Mooleki, S. P.
    • Lemke, R. L.
    • Thavarajah, D.
    • Hultgreen, G.
    • May, W. E.
  • Source: Canadian Journal of Plant Science
  • Volume: 89
  • Issue: 1
  • Year: 2009
  • Summary: No-till (NT) requires all fertilizer nutrients to be applied during planting, but high rates of fertilizer nitrogen (N) in close proximity to the seed can negatively affect seedling development; therefore, different placement technologies have been developed to place seed and N in a single operation while maintaining an adequate separation between them. We conducted a 3-yr field study (2000 to 2002) at four sites in Saskatchewan. The objective was to determine the effects of N fertilizer form [urea (U) and anhydrous ammonia (AA)], placement [broadcast, side-band (SB) and mid-row band (MRB)], timing (fall vs. spring), rate (0 to 90 or 120 kg N ha -1), and P fertilizer placement on yield, seed protein content and N uptake in canola. The N fertilizer managements had no significant effect on crop emergence. Yield, seed protein concentration and N uptake increased with increasing N fertilizer rate. Seed protein was significantly higher on SB compared with MRB and on U compared with AA. Seed yield and seed and straw N uptake were higher when U was SB compared with broadcast. Plant density was higher when P was placed in SB rather than with the seed, but the reverse was true for seed yield and seed N uptake.
  • Authors:
    • Fortin, J.
    • Tremblay, G.
    • Ziadi, N.
    • Chantigny, M. H.
    • Rochette, P.
    • Angers, D. A.
    • Poirier, V.
  • Source: Soil Science Society of America Journal
  • Volume: 73
  • Issue: 1
  • Year: 2009
  • Summary: Both tillage and fertilizer management influence soil organic C (SOC) storage, but their interactive effects remain to be determined for various soil and climatic conditions. We evaluated the long-term effects of tillage (no-till, NT, and moldboard plowing, MP), and N and P fertilization on SOC stocks and concentrations in profiles of a clay loam soil (clayey, mixed, mesic Typic Humaquept). Corn (Zea mays L.) and soybean [Glycine max (L) Merr.] were grown in a yearly rotation for 14 yr. Our results showed that NT enhanced the SOC content in the soil surface layer, but MP resulted in greater SOC content near the bottom of the plow layer. When the entire soil profile (0-60 cm) was considered, both effects compensated each other, which resulted in statistically equivalent SOC stocks for both tillage practices. Nitrogen and P fertilization with MP increased the estimated crop C inputs to the soil but did not significantly influence SOC stocks in the whole soil profile. At the 0- to 20-cm depth, however, lower C stocks were measured in the plowed soil with the highest N fertilizer level than in any other treatment, which was probably caused by a greater decomposition of crop residues and soil organic matter. Conversely, the highest SOC stocks of the 0- to 20-cm soil layer were observed in the NT treatment with the highest N rates, reflecting a greater residue accumulation at the soil Surface. When accounting for the whole soil profile, the variations in surface SOC due to tillage and fertilizer interactions were masked by tillage-induced differences in the 20- to 30-cm soil layer.