• Authors:
    • Menzies, J. G.
    • Haber, S. M.
    • Fetch, T. G.,Jr.
    • Chong, J.
    • Ames, N.
    • Brown, P. D.
    • Fetch, J. W. M.
    • Tekauz, A.
    • Townley-Smith, T. F.
    • Stadnyk, K. D.
  • Source: Canadian Journal of Plant Science
  • Volume: 91
  • Issue: 2
  • Year: 2011
  • Summary: Stainless is a grey-hulled spring oat ( Avena sativa L.) cultivar postulated to carry the crown rust resistance gene, Pc91, which was effective against the prevalent pathotypes of crown rust races on the Canadian prairies at the time of its release. Stainless could possibly also carry one or more of the crown rust resistance genes, Pc38, Pc39, and Pc68. It had very good resistance to loose and covered smut, good resistance to the prairie stem rust races (likely due to the presence of Pg2, Pg13, and Pga) and moderate tolerance to barley yellow dwarf virus (BYDV). Stainless had high kernel weight, intermediate percent plump kernels, intermediate percent thin kernels, and high levels of total dietary fibre. Stainless exhibited high yielding capacity in the eastern portion of the Black soil zone of western Canada where resistance to rust diseases is important. Stainless was supported for registration by the Prairie Grain Development Committee in February 2007. Stainless was registered (Reg. No. 6422) on 2008 Apr. 07.
  • Authors:
    • Menzies, J. G.
    • Haber, S. M.
    • Fetch, T. G.,Jr.
    • Chong, J.
    • Ames, N.
    • Brown, P. D.
    • Fetch, J. W. M.
    • Tekauz, A.
    • Townley-Smith, T. F.
    • Stadnyk, K. D.
  • Source: Canadian Journal of Plant Science
  • Volume: 91
  • Issue: 4
  • Year: 2011
  • Summary: Summit is a white-hulled spring oat ( Avena sativa L.) cultivar postulated to carry the crown rust resistance combination Pc38, Pc39, Pc48, and Pc68, which was effective against the prevalent pathotypes of crown rust 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 is resistant to moderately resistant to barley yellow dwarf virus (BYDV). Summit has good kernel weight, percent plump kernels, and percent thin kernels. Summit exhibits high yielding capacity in the oat growing areas of western Canada. Summit was registered (Reg. No. 6529) in Canada 2008 November 29.
  • Authors:
    • Alvarez-Mozos, J.
    • Larranaga, A.
    • Albizua, L.
  • Source: Canadian Journal of Remote Sensing
  • Volume: 37
  • Issue: 1
  • Year: 2011
  • Summary: Multispectral optical remote-sensing systems have been the base for crop identification and monitoring for many years. However, cloud cover limits and even prevents the use of optical data for this activity. Synthetic aperture radar (SAR) sensors provide an interesting alternative to conventional multispectral classification schemes. Radar sensors can acquire data regardless of cloud cover, and their observations provide complementary information to that captured by optical sensors. The main objective of this paper is to evaluate whether the incorporation of polarimetric SAR observations to a multispectral classification scheme enhances classification results using the proposed method. With this aim, one Landsat thematic mapper scene and two ALOS/PALSAR quadrature polarization scenes acquired in 2007 were processed. The results demonstrated the ability of SAR data to improve the classification based on optical images. However, improvements were slight (an increase of around 2% in the classification's overall accuracy). The results improved significantly when barley, wheat, and oats were considered a single class, called cereals. The best results were achieved using Landsat and the two ALOS/PALSAR scenes together, obtaining an overall Kappa coefficient and accuracy of 0.67 and 90%, respectively. Probably, scenes acquired on other dates (June and July) would have yielded clearer classification enhancements.
  • Authors:
    • Foster, A.
    • Malhi, S.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 42
  • Issue: 19
  • Year: 2011
  • Summary: Annual cover crops compete with underseeded perennial forages for light, moisture, and nutrients and may suppress their establishment and growth. Field experiments were established in 2000 and 2001 at Nipawin and in 2002 and 2003 at Melfort in northeastern Saskatchewan to determine the effects of seeding rates of cover crops of oat (19, 38, and 112 kg ha -1) and barley (31, 62, and 124 kg ha -1) on forage dry-matter yield (DMY) of the cover crop cut as greenfeed in the seeding year, DMY of the underseeded meadow bromegrass-alfalfa mixture in the following 1 or 2 years after establishment, and forage quality [concentration of crude protein (CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF)]. In the first establishment year, the no cover crop treatment produced considerably less DMY than the treatments with cover crops. Oat seeded at 112 kg ha -1 produced greater DMY than when it was seeded at 19 or 38 kg ha -1 in all four site-years, but DMY differences between the 19 or 38 kg ha -1 seeding rates were not significant in any site-year. For barley, there was no significant difference in DMY among the three seeding rates in 2000, 2001, and 2002. In 2003, barley seeded at 62 or 124 kg ha -1 produced greater DMY than when it was seeded at 31 kg ha -1, but DMYs were not significantly different between the 62 and 124 kg ha -1 seeding rates. The use of a cover crop did reduce DMY in 2003 of bromegrass-alfalfa mixture underseeded in 2002, but the type of cover crop and its seeding rate did not appear to affect DMY in any site-year. Forage quality in the seeding year was consistently superior in no cover crop treatment compared to that in treatments with cover crops, especially related to CP concentration. There was no consistent trend of forage quality in the cover crop treatments, indicating cover crops and their seeding rates had little effect on forage quality. In conclusion, oat appeared to be more sensitive to seeding rate than barley for forage DMY in the establishment year, but in the subsequent 1 or 2 years after establishment there was little effect of cover crop type and its seeding rate on DMY of bromegrass-alfalfa mixture, although DMY was considerably greater in the no cover treatment than that in treatments with cover crops in 1 site-year.
  • Authors:
    • O'Donovan, J.
    • Harker, K.
    • Clayton, G.
    • Brandt, R.
    • Hao, X.
    • Blackshaw, R.
    • Johnson, E.
    • Vera, C.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 1
  • Year: 2011
  • Summary: Nitrogen fertilizer is a major input cost in canola ( Brassica napus L.) production and farmers are interested in improving N use efficiencies. A multi-site study in western Canada was conducted to determine the merits of polymer-coated urea (Environmentally Smart Nitrogen, ESN) compared with urea on weed management and yield of hybrid and open-pollinated (OP) canola. Treatments included a hybrid and OP canola cultivar, ESN and urea, 100 and 150% of soil test N fertilizer rates, and 50 and 100% of registered in-crop herbicide rates. Canola was grown in rotation with barley ( Hordeum vulgare L.) in a no-till system and both crops of the rotation were present each year. Fertilizer and herbicide rate treatments were applied to the same plots in four consecutive years to determine annual and cumulative effects. Hybrid compared with OP canola reduced weed tissue N concentration in 40% of the cases and reduced weed biomass in 80% of the cases. Additionally, weed tissue N concentration was lower with ESN than with urea in 70% of the cases, indicating that crop-weed competition for soil N might be reduced if ESN were used. Canola yield was greater for the hybrid cultivar in 15 of 20 site-years. Both cultivars expressed a positive yield response to the 150% N fertilizer rate in 10 of 20 site-years. This yield response occurred in three additional site-years with hybrid canola, indicating that hybrid cultivars have a higher N demand under favorable growing conditions. Canola yield was similar with ESN and urea in 14 of 20 site-years. The ESN compared with urea increased canola yield in 4 site-years and in one additional site-year for hybrid canola, indicating that ESN may be advantageous in some situations. Canola seed oil concentration was similar with ESN and urea in 19 of 20 site-years. Information gained in this study will be used to develop improved fertilization strategies for canola production on the semiarid Canadian prairies.
  • Authors:
    • Janzen, H. H.
    • Ellert, B. H.
    • McKenzie, R. H.
    • Bremer, E.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 4
  • Year: 2011
  • Summary: Agroecosystems provide a range of benefits that are strongly influenced by cropping practice. Crop productivity and C, N, and greenhouse gas (GHG) balances were evaluated in an 18-yr cropping system study on an Aridic Haplustoll in the northern Great Plains. Application of synthetic fertilizers consistently increased crop yield and soil organic carbon (SOC), with greatest impact in perennial grass and continuous wheat ( Triticum aestivum L.) rotations and least impact in rotations with fallow or annual legumes. Based on N balance, N inputs other than fertilizer were 16 to 30 kg N ha -1 yr -1 in rotations without legumes and 62 kg N ha -1 yr -1 in a legume-wheat (LW) rotation, while losses of synthetic fertilizer N were 32% in annual crop rotations and 3% in perennial grass. Due to large gains in SOC, perennial grass reduced atmospheric GHG by 20 to 29 Mg CO 2 equivalent (eq.) ha -1 during the 18 yr of this study. For annual crop rotations, seed yield ranged from 1.2 to 2.5 Mg ha -1 yr -1, protein yield from 0.20 to 0.41 Mg ha -1 yr -1, and GHG intensity from 0 to 0.5 Mg CO 2 eq. Mg -1 seed. Fertilized continuous wheat had the highest crop productivity and lowest net GHG intensity, while an annual LW rotation had the highest protein productivity and among the lowest GHG intensities (0.2 Mg CO 2 eq. Mg -1 seed). Further evaluation at broader temporal and spatial scales is necessary to account for future changes in SOC and differences in use of crop products.
  • Authors:
    • VandenBygaart, A. J.
    • Zentner, R. P.
    • Lemke, R.
    • May, W. E.
    • Holzapfel, C. B.
    • Campbell, C. A.
    • Lafond, G. P.
  • Source: Canadian Journal of Plant Science
  • Volume: 91
  • Issue: 3
  • Year: 2011
  • Summary: We analyzed the agronomic data from a 50-yr crop rotation experiment being conducted on a fine-textured, thin Black Chernozem at Indian Head, Saskatchewan in Canada. Our objective was to determine how a change from conventional-till to no-till, together with an increase in N fertilizer rates recommended by the Saskatchewan Soil Testing Laboratory has affected wheat yields and N and P balance in the systems over the past 20 yr. The treatments assessed were fertilized (N-P) and unfertilized fallow-wheat ( Triticum aestivum L.) (F-W), F-W-W, and continuous wheat (ContW), and unfertilized legume green manure (LGM)-W-W and F-W-W-brome ( Bromus inermis Leyss.)/alfalfa ( Medicago sativa L.) hay (H)-H-H. On average, N applied to wheat grown on fallow was 6 kg ha -1 yr -1 from 1957 to 1989 and 57 kg ha -1 yr -1 from 1990 to 2007; for wheat grown on stubble, the N rates were 21 kg ha -1 yr -1 from 1957 to 1977 and 85 kg ha -1 yr -1 thereafter. Crops received P at 10 kg ha -1 yr -1. On average, fertilizer increased wheat yield of fallow-wheat by 31%; the hay system increased fallow-wheat yield by 26% compared with unfertilized fallow-wheat in F-W-W, and the LGM system increased it by 14%. Effects were greater on stubble crop than on fallow crop, with fertilizer increasing the yield of wheat grown on stubble in the monoculture system by 114%, the hay system increasing it by 83% and the LGM system increasing it by 37%. The legume-containing rotations increased yields by increasing the N supplying capacity of the soil with the hay system being more effective than the LGM because legumes occurred more frequently in the hay rotation (3 in 6 yr vs. 2 in 6 yr). The benefit of the legume-containing systems on wheat yield may have been restricted because this unfertilized system steadily depleted available soil P. Average annualized wheat production in F-W, F-W-W and ContW rotations was unaffected by cropping frequency for the unfertilized systems, but it was directly proportional to cropping frequency for the fertilized systems. Annualized wheat production for the LGM-W-W rotation was 18% greater than for unfertilized F-W-W, but 41% less than for the fertilized F-W-W. Annualized wheat production in the hay-containing rotation was 32% less than in the unfertilized F-W-W rotation because of the less frequent presence of wheat in the hay system. Greater rates of N fertilizer in the later years increased yields and grain N content; this resulted in less residual NO 3-N in the soil compared with previous years with lower fertilizer N. Thus, we expect there will be less likelihood of NO 3 leaching under fallow-containing systems under no-till when updated fertilizer recommendations are used compared with previous results under conventional tillage with lower rates of N applications.
  • Authors:
    • Fernandez, M. R.
    • Ulrich, D.
    • Brandt, S. A.
    • Zentner, R. P.
    • Wang, H.
    • Thomas, A. G.
    • Olfert, O.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 3
  • Year: 2011
  • Summary: The impact of cropping system management on root and crown rot of spring wheat ( Triticum aestivum L.) was examined on a Dark Brown Chernozem (Typic Boroll) soil in the Canadian Prairies. This systems approach tried to reflect the most common practices of organic and conventional producers in this region. The study consisted of a factorial combination of three input levels (high, with tillage, fertilizer and pesticides; reduced [RED], with conservation tillage, targeted fertilizer and weed control; and organic [ORG] with tillage and N-fixing legumes); and three levels of cropping diversity (low diversity with wheat and summerfallow or legume green manure fallow; diversified using annual grain crops; and diversified using annual grain crops and perennial forages). All rotations were 6 yr long. Subcrown internodes and crowns/lower culms of wheat plants were scored for discoloration, and fungi in discolored tissue were identified and quantified. Overall, input level had a greater impact on disease levels and fungal frequency than cropping diversity. Discoloration severity was lowest in the RED systems, which was attributed to lower percentage isolation of Cochliobolus sativus, the most common pathogen. Fusarium species varied with input level. The pathogens F. avenaceum and F. culmorum were most associated with RED and/or least associated with ORG systems, whereas the weak pathogen/saprophyte F. equiseti was most associated with ORG systems. Thus, ORG management helped to reduce populations of F. avenaceum and F. culmorum, two of the most important Fusarium pathogens in the Canadian Prairies.
  • Authors:
    • Rickman, R. W.
    • Liang, Y.
    • Albrecht, S. L.
    • Machado, S.
    • Kang, S.
    • Gollany, H. T.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 1
  • Year: 2011
  • Summary: Long-term field experiments (LTE) are ideal for predicting the influence of agricultural management on soil organic carbon (SOC) dynamics and examining biofuel crop residue removal policy questions. Our objectives were (i) to simulate SOC dynamics in LTE soils under various climates, crop rotations, fertilizer or organic amendments, and crop residue managements using the CQESTR model and (ii) to predict the potential of no-tillage (NT) management to maintain SOC stocks while removing crop residue. Classical LTEs at Champaign, IL (1876), Columbia, MO (1888), Lethbridge, AB (1911), Breton, AB (1930), and Pendleton, OR (1931) were selected for their documented history of management practice and periodic soil organic matter (SOM) measurements. Management practices ranged from monoculture to 2- or 3-yr crop rotations, manure, no fertilizer or fertilizer additions, and crop residue returned, burned, or harvested. Measured and CQESTR predicted SOC stocks under diverse agronomic practices, mean annual temperature (2.1-19 degrees C), precipitation (402-973 mm), and SOC (5.89-33.58 g SOC kg(-1)) at the LTE sites were significantly related (r(2) = 0.94, n = 186, P < 0.0001) with a slope not significantly different than 1. The simulation results indicated that the quantities of crop residue that can be sustainably harvested without jeopardizing SOC stocks were influenced by initial SOC stocks, crop rotation intensity, tillage practices, crop yield, and climate. Manure or a cover crop/intensified crop rotation under NT are options to mitigate loss of crop residue C, as using fertilizer alone is insufficient to overcome residue removal impact on SOC stocks.
  • Authors:
    • Hammond, R.
  • Source: IOBC/WPRS Bulletin
  • Volume: 64
  • Year: 2011
  • Summary: Slugs are often problems in field crops grown using conservation tillage practices in the eastern United States, as well as certain locations in the Midwest and the southern USA, as well as in Canada. Although most concern has been on corn and soybean, reports of problems from dry beans, cotton, oil-seed rape, sunflowers, winter wheat, and fall planted alfalfa are often received. Although most problems are in fields located in the original forested areas of eastern and southern USA, reports are also being received from the Great Plains' grass lands of slug issues in irrigated no-till fields. Overall, slug problems have increased in geographical area as growers in the USA and Canada have adopted conservation tillage practices. As in other areas of the world, determining new methods of slug control is of utmost importance in order to allow growers to continue using conservation tillage practices. In areas that are new to slugs, a primary concern is educating growers on IPM approaches to slug management.