Nitrogen cycling and budget in crop rotations as influenced by preceding crops and N fertilization

Non-Peer Reviewe

Optimizing the Productivity and Resiliency of Cropping Systems in the Major Ecozones on the Canadian Prairies

Non-Peer ReviewedAgriculture faces grand challenges of meeting growing food demands and increasing profitability while reducing environmental impacts. A systems approach is required to design and manage cropping systems to meet the goal of agricultural sustainability under climate change. A 4-year rotation study was established in 2018 at seven sites across the Canadian Prairies, including Beaverlodge, Lacombe, and Lethbridge, AB; Melfort, Scott, and Swift Current, SK; and Carman MB. The objective of this project is to develop resilient cropping systems for different ecozones on the Canadian Prairies. This study tested six cropping systems consisting of 1) conventional cropping system (Control), 2) pulse- or oilseed-intensified cropping system (POS), 3) diversified cropping system (DS), 4) market-driven cropping system (MS), 5) high risk and high reward cropping system (HRHRS), and 6) green-manure incorporated soil-health focused cropping system (GMS). Each cropping system varies slightly among experimental sites (ecozones) to mimic local farming practices. Cropping system indicators such as yield, resource use efficiency, soil health, profitability, environmental impact, resiliency, and sustainability will be fully assessed at the end of rotations. The preliminary results from the first 2 years indicated that there was no single cropping system suitable for all study ecozones although POS had an above-average yield and stability among the six cropping systems. We suggest that the optimal cropping system will maximize yield in the high-yielding ecozones and stabilize yields in the low-yielding ecozones. Link to Video Presentation: https://youtu.be/VsK4RNIzaZ

Benefits of mixed grass–legume pastures and pasture rejuvenation using bloat-free legumes in western Canada: a review

Forage mixtures containing legume out-yield monocultures, fix atmospheric nitrogen, and have lower carbon footprints. However, evidence-based information on creating forage mixtures by direct seeding legumes into existing pastures is limited, and information on bloat-free legumes is nonexistent. Traditionally, pastures requiring improvement in western Canada were fully replaced by breaking up the old stand and reseeding. With new and improved forage cultivars, better seeding equipment, and increased knowledge about pasture management, there is a growing interest among producers in rejuvenating pastures instead of replacing them. Pasture rejuvenation refers to the improvement in biomass productivity and (or) nutritional quality of existing pasture without removing the existing vegetation. This can be done through fertilizer application, which is generally expensive and causes negative environmental impacts. Amelioration of compacted pastureland via mechanical aeration is short-lived and can lead to weed problems. As an alternative, direct seeding of productive, nutritive and bloat-free legume species into existing pasture is an attractive option for pasture rejuvenation. For high performance grazing systems, identification of suitable bloat-free legumes and methods for direct seeding into old grass and legume stands will be essential strategies. This review includes information on the benefits of mixed pastures and seeks possible methods of introducing bloat-free forage legumes into existing pastures in western Canada for rapid improvement in productivity and quality while positively influencing animal, soil, and environmental health.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