Management Strategies and Practices for Preventing Nutrient Deficiencies in Organic Crop Production

Field experiments are underway in Canada to determine the influence of management practices (crop diversity, green manure, legumes) and amendments (Penicillium bilaiae, rock phosphate, elemental S, gypsum, manure, wood ash, alfalfa pellets) on crop yield. In the alternative cropping systems study established in 1995, crop yields for organic system without any chemical input were 30-40% lower than the conventional system with high inputs. But, lower input costs plus price premiums for organic produce normally more than offset lower yields, resulting in favourable economic performance and energy efficiency. Legume, green manure and compost manure helped to replace nutrients lacking in the soil and improved crop yields. In the organic system, amount of P removed in crop exceeded that of P replaced and this can be a major yield limiting factor. In amendments experiments, there was small effect of granular rock phosphate fertilizer and/or Penicillium bilaiae in increasing soil P level and crop yield in the application year. Other findings suggested the use of elemental S fertilizer, gypsum, manure, wood ash or alfalfa pellets to improve nutrient availability, and yield and quality of produce. In conclusion, integrated use of management practices and amendments has the potential to increase sustainability of crop production as well as improve soil quality plus minimize environmental damage

Canola growth, production and quality are influenced by seed size and seeding rate

Canola (Brassica napus L.) is the most widespread profitable cash crop in Canada. In 2014 and 2015, direct-seeded experiments were conducted in sixteen western Canada environments. “Small” canola seed (average 3.32 to 3.44 g 1000-1) was compared to “large” canola seed (average 4.96 to 5.40 g 1000-1) at five seeding rates (50, 75,100, 125 or 150 seeds m-2). Large canola seeds increased crop density and crop biomass but decreased plant mortality, days to start of flowering, days to end of flowering, days to maturity and percent green seed. Seed size did not influence harvested seed weight, seed oil content or seed protein content. Increasing the seeding rate of small seeds improved canola yield, but the same response did not occur for large seeds. Increasing seeding rates also increased crop density, plant mortality, crop biomass and seed oil content but decreased days to start of flowering, days to end of flowering, days to maturity, percent green seed and seed protein content. Seeding rate had no impact on harvested seed weights. Because higher seeding rates often provide some of the same benefits as large seed, canola growers and the seed industry should balance seed size and seeding rate to obtain the best agronomic performance from canola.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author