161 research outputs found

    Does seed size affect alfalfa establishment and productivity in saline seedbeds?

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    Non-Peer ReviewedLarge, medium and small seeds of Rangelander alfalfa, were sown in saline media in Canada’s Salt Tolerance Testing Lab. The emergence and survival data indicate that large-size seeds confer a degree of salinity tolerance to their emerging and developing seedlings. The large seeds emerged in numbers 10 and 23 % greater than the plants from medium and small seeds grown in 18 and 24 dS m-1 solutions, respectively. The seed-size advantage, evident in plant heights just 14 days after seeding, persisted into forage harvests which also showed increased biomass yields at all salinity levels at the first harvest cut. Although the seed-size yield advantages diminished with successive harvests, higher yields persisted at the 12 and 18 dS m-1 salinity treatments for the crops planted with large seeds

    Pre-irrigation of a severely-saline soil with in-situ water to establish dryland forages

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    Non-Peer ReviewedAlfalfa serves as one of the most important forage plants in North America. It is also the recommended remedial crop for dryland salinity control. But, because of its limited salt tolerance, it does not establish satisfactorily in severely or moderately saline soils. A series of irrigations with the in-situ ground water located beneath a severely-saline site were delivered across seedbeds prepared within the same site prior to seeding ‘Beaver’ alfalfa (Medicago sativa) and ‘ AC Saltlander’ green wheatgrass (Elymus Hoffmannii). In this field study conducted in semiarid Saskatchewan, fall irrigations with 4.6 dS/m-water from a shallow, on-site, backhoe-dug well fitted with a solar-powered pump preceded spring seeding. Irrigation treatments ranged from zero to 2530 mm in total applied water. Plant emergence, spacing, height, cover, and forage yield of the alfalfa were significantly improved following pre-irrigation. Mean plant emergence increased from 20 to 79% for the alfalfa. The wheatgrass height and forage yield also improved significantly, but showed only an upward trend in emergence, spacing, height, and cover. The mean plant height in July increased from 90 to 159 mm for the wheatgrass and from 35 to 140 mm for the alfalfa. Based on linear regression of irrigated volume, every 119.3 mm of irrigated, in-situ water up to 2530 mm increased alfalfa forage yield by 10 g/m2

    Effects of fallow replacement green manuring with annual legumes on soil water reserves

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    Non-Peer ReviewedLegume green manures are used in crop rotations to add organic matter, enhance N availability and to provide ground cover for soil conservation. In drought-prone regions like the Palliser Triangle, annual rather than perennial legumes could be used for fallow replacement green manuring in short rotations to avoid excessive depletion of soil water reserves. Results from a 6-year study of green manuring with 4 annual legumes in combination with snow trapping on a Brown loam at Swift Current were used to assess water use during legume growth, water use efficiency (WOE) of green manure production and amounts of soil water remaining for subsequent spring wheat. Each spring Black lentil, Tangier flatpea, Chickling vetch and Feedpea were seeded into wheat stubble with tall stubble trap strips along with continuous wheat and wheat-fallow plots. Legumes were incorporated in some and chemically desiccated in other plots as soon as they reached full bloom. Water use by the 4 legumes was generally related to DM production and did not differ from the amount used by wheat during the same vegetative growth period. Most of the water used was extracted from the 0- to 60-cm soil depth. On average, inoculated legumes used only 12% more water but produced much more DM than uninoculated legumes. Thus rhizobial seed inoculation and the enhanced N2-fixation elicited a doubling of the WUE by these green manures. Chickling vetch and feedpea were able to use water at a 20% greater efficiency than well fertilized spring wheat. Contrary to expectations, levels of soil water recharge between legume bloom and the following spring were always as high for incorporated as for desiccated green manures. At seeding time there was generally 20% less water under continuous wheat than in the fallow soil. In green manured soils, water reserves in spring did not differ between legume species and were usually 15% lower than in fallow plots with wheat trap strips. Wheat yields after green manures were affected primarily by weather and legume management but not by legume species. After incorporated green manures grain production was, on average, 12% and 17% greater than after conventional fallow or desiccated green manure, respectively. The presence of wheat strips in the fallow phase increased subsequent grain yields by an average 20%. We concluded that green manuring with annual legumes, when combined with snow trapping, offers a more bio-resource efficient and soil conserving alternative to conventional summer fallowing for wheat production within the Palliser Triangle

    Grass barriers for wheat production in southwest Saskatchewan

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    Non-Peer ReviewedWind has long been considered a bane to farming in the Brown and Dark Brown Soil Zones of southwest Saskatchewan. Blowing dust from rampant wind erosion in an all-too-often occurrence. Strong hot summer winds cause tremendous moisture stress to crops – particularly in dry years when crops are already drought-stressed. Perennial vegetative windbreaks have been advocated as a way to reduce near-surface windspeeds both to control wind erosion and to improve crop yields through better water conservation and decreased in-crop evaporative stress
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