275 research outputs found
Nitrogen fertilizer placement – an important component in the 4R nutrient stewardship
Non-Peer Reviewe
Sulphur for wheat protein
Non-Peer ReviewedThe effectiveness of supplementing Sulphur (S) to Canada west red spring (CWRS) and Durum
wheat to increased grain protein levels was assessed in a three-year 10 trial experiment. Five
rates of N (0, 36, 54, 72 and 90 lb/acre) and two rates of S (0 and 22 lb S/acre) were arranged in
a complete randomized block design with either four or six replicates. Soils at the sites varied
from S deficient to S sufficient, based on criteria utilized in western Canada. Application of 22
lb S/acre resulted in no yield increases; a protein content increase was obtained in a soil that
contained extremely low S levels in the 0-12 inch depth. Protein content in the grain was
directly related to N fertilization and growing season (May, June, July) precipitation. Hence,
deliberate and indiscriminate application of S to increase protein in CWRS and Durum wheat
grain is not a recommended practice, unless S deficiency is corrected in which case an indirect
benefit of increased grain protein might ensue
Soil Testing Then and Now – So What has Changed?
Non-Peer Reviewe
Fall and spring placement of nitrogen fertilizers. Where do enhanced efficiency fertilizers fit?
Non-Peer Reviewe
Effect of time and rate of application of anhydrous ammonia and urea with or without a nitrification inhibitor on the yield and quality of a barley-wheat-canola rotation
Non-Peer ReviewedA project was initiated in the fall of 2006 to compare the effect of early (mid-September) and late (mid to late October) fall, and spring application of anhydrous ammonia and urea on the yield of barley, wheat and canola in barley-wheat-canola-wheat rotation. The experiment now in its third year is being carried out in two locations (Watrous and Lake Lenore) and involves four rates of N (0, 30, 80 and 120 kg N ha-1) with or without treatment with a nitrification inhibitor (N-Serve) annually applied on the same plots and four replicates for a total of 39 treatments. Consistent significant differences in all six-site years were responses to N and anhydrous vs. urea, the latter being a result of the inefficiency of the low N rate (40 kg ha-1) when applied as anhydrous ammonia. Overall, there were no differences due to time of application
Nitrogen, phosphorus, and rhizobial strain responses of lentil
Non-Peer ReviewedThree field experiments were set out in 1987 to test the effect of nitrogen fertilizer, phosphorus fertilizer, and rhizobial strain on lentil yields and N2-fixation. The following treatments were laid out in a split-split-plot design: main plot treatments of uninoculated, Nitragin 'C' inoculated, and strain 99A1 inoculated lentil; sub-plot treatments of 0 and 30 kg P/ha, and sub-sub plot treatments of 0, 10, 20, 40, or 80 kg N/ha 15N-enriched fertilizer was applied to a 1.05 m2 micro-plot in each plot Barley was used as the non-N2-fixing reference crop. At all sites lentil inoculated with strain 99A1 had the greatest total dry matter yield, grain yield and N2 fixed. Uninoculated lentil had a strong N response at all sites, 'C' inoculated lentil had a starter N response at Kindersley and 99 A1 inoculated lentil had no N response at all. P responses were only observed at Foam Lake. Lentil receiving low amounts of N fertilizer obtained between 60 and 75 % of their N from the atmosphere at all sites. A good agreement was observed in estimating percent N derived from N2 using the 15N isotope dilution, A-value, or classical N-difference methods. The amount of fixed N in the seed ranged from 4 kg ha-1 under drought stressed conditions at Kindersley to 60 kg ha-1 under much better growing conditions at Foam Lake
Reducing rates of Agrotain® for seedrow applications
Non-Peer Reviewe
The impact of DCD and NBPT concentration on nitrification and volatilization
Non-Peer ReviewedNitrification inhibitors are used in agriculture to slow the conversion of ammonium to nitrate by inhibiting ammonia monoxygenace (AMO), which is found within the Nitrosomonas bacteria. There are two ways to inhibit nitrification of the AMO enzyme, namely, (a) competitive inhibition: The inhibitor will compete to occupy AMO's active site; by blocking the active site, it slows the conversion of ammonium to nitrate preventing loss of nitrates, and, (b) non-competitive inhibition: The inhibitor can temporarily inactivate the AMO enzyme by altering the active site. Dicyandiamide (DCD) is a competitive inhibitor. The amount of DCD delivered by a product has a direct impact on how well a product will inhibit loss of nitrogen through nitrification. Research shows the concentration of DCD in the soil has a direct influence on the percent of nitrification. Higher concentrations of DCD equate to higher percentage of nitrification inhibition. The results of a two-year program that compares two products, one containing 8500 ppm and one 870ppm of DCD and approximately equal concentration of a volatilization inhibitor will be presented
Ethnic differences in and childhood influences on early adult pulse wave velocity: the determinants of adolescent, now young adult, social wellbeing, and health longitudinal study
Early determinants of aortic stiffness as pulse wave velocity are poorly understood. We tested how factors measured twice previously in childhood in a multiethnic cohort study, particularly body mass, blood pressure, and objectively assessed physical activity affected aortic stiffness in young adults. Of 6643 London children, aged 11 to 13 years, from 51 schools in samples stratified by 6 ethnic groups with different cardiovascular risk, 4785 (72%) were seen again at aged 14 to 16 years. In 2013, 666 (97% of invited) took part in a young adult (21–23 years) pilot follow-up. With psychosocial and anthropometric measures, aortic stiffness and blood pressure were recorded via an upper arm calibrated Arteriograph device. In a subsample (n=334), physical activity was measured >5 days via the ActivPal. Unadjusted pulse wave velocities in black Caribbean and white UK young men were similar (mean±SD 7.9±0.3 versus 7.6±0.4 m/s) and lower in other groups at similar systolic pressures (120 mm Hg) and body mass (24.6 kg/m2). In fully adjusted regression models, independent of pressure effects, black Caribbean (higher body mass/waists), black African, and Indian young women had lower stiffness (by 0.5–0.8; 95% confidence interval, 0.1–1.1 m/s) than did white British women (6.9±0.2 m/s). Values were separately increased by age, pressure, powerful impacts from waist/height, time spent sedentary, and a reported racism effect (+0.3 m/s). Time walking at >100 steps/min was associated with reduced stiffness (P<0.01). Effects of childhood waist/hip were detected. By young adulthood, increased waist/height ratios, lower physical activity, blood pressure, and psychosocial variables (eg, perceived racism) independently increase arterial stiffness, effects likely to increase with age
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