Thiessen Martens, J. R., Entz, M. H. and Wonneck, M. D. 2015. Review: Redesigning Canadian prairie cropping systems for profitability, sustainability, and resilience. Can. J. Plant Sci. 95: 1049Á1072. Redesign of agricultural systems according to ecological principles has been proposed for the development of sustainable systems. We review a wide variety of ecologically based crop production practices, including crop varieties and genetic diversity, crop selection and rotation, cover crops, annual polyculture, perennial forages, perennial grains, agroforestry systems, reducing tillage, use of animal manures and green manures, soil biological fertility, organic production systems, integrated cropÁlivestock systems, and purposeful design of farm landscapes (farmscaping), and discuss their potential role in enhancing the profitability, environmental sustainability, and resilience of Canadian prairie cropping systems. Farming systems that most closely mimic natural systems through appropriate integration of diverse components, within a context of supportive social and economic structures, appear to offer the greatest potential benefits, while creating a framework in which to place all other farming practices. Our understanding of ecological relationships within agricultural systems is currently lacking, and a major shift in research, education, and policy will be required to purposefully and proactively redesign Canadian prairie agricultural systems for long-term sustainability.

Cicek, H., Entz, M. H., Thiessen Martens, J. R. and Bullock, P. R. 2014. Productivity and nitrogen benefits of late-season legume cover crops in organic wheat production. Can. J. Plant Sci. 94: 771–783. When full-season cover crops are used in stockless organic rotations, cash crop production is compromised. Including winter cereals in rotations can widen the growing season window and create a niche for late-season cover crops. We investigated the establishment and biomass production of relay-cropped red clover (Trifolium pratense L.) and sweet clover (Melilotus officinalis L. ‘Norgold’) and double-cropped cowpea (Vigna unguiculata L. ‘Iron and Clay’), hairy vetch (Vicia villosa L.), lentil (Lens culinaris L. ‘Indianhead’), soybean (Glycine max L. ‘Prudence’), pea (Pisum sativum L. ‘40-10’), and oil seed radish (Raphanus sativus L.) as well as wheat response to these crops under reduced tillage (RT) and conventional tillage (CT) at three locations in Manitoba, Canada. Red clover, sweet clover and pea produced from 737 to 4075 and 93 to 1453 and 160 to 2357 kg ha−1of biomass, respectively. All double crops, with the exception of soybean at 2 site years, established successfully under both RT and CT. The presence of cover crops increased wheat N uptake at stem elongation, maturity and yield, even when the biomass production of cover crops was modest. We conclude that late-season cover crops enhance the following wheat yield and facilitate reduced tillage in organic crop production.

I. 2014. Green manure species respond differently to blade rolling. Can. J. Plant Sci. 94: 1507Á1511. Reducing tillage in green manure (GM) management has led to interest in using the blade roller in organic agriculture. This study investigated the interaction effect of GM termination method (blade rolling and conventional tillage) and GM species choice [chickling vetch (Lathyrus sativus L.), Indian Head lentil (Lens culinaris), and hairy vetch (Vicia villosa Roth)] on a subsequent crop of hard red spring wheat (Triticum aestivum L.). Significant effects on weed density and biomass, wheat biomass, and wheat yield indicated that the GM species were affected differently by termination methods. It was also discovered that spring-seeded hairy vetch continues to grow after rolling, while chickling vetch and lentil die. Vaisman, I., Entz, M. H., Bamford, K. C. et Cushon, I. 2014. Les espe`ces employe´es comme engrais vert re´agissent diffe´remment au rouleau a`lames. Can. J. Plant Sci. 94: 1507Á1511. La possibilite´de re´duire les labours dans les cultures d'engrais vert a suscite´de l'inte´reˆt pour le rouleau a`lames en agriculture biologique. Cette e´tude examine l'interaction de la me´thode employe´e pour interrompre la culture de l'engrais vert (rouleau a`lames ou labours classiques) et de l'espe`ce [gesse cultive´e (Lathyrus sativus L.), lentille Indian Head (Lens culinaris) et vesce velue (Vicia villosa Roth)] avec la culture subse´quente de ble´roux vitreux de printemps (Triticum aestivum L.). Les conse´quences appre´ciables sur la densite´et la biomasse des adventices, sur la biomasse du ble´et sur le rendement du ble´indiquent que le type d'engrais vert re´agit diffe´remment a`la me´thode utilise´e pour le couper. On a aussi de´couvert que la vesce velue seme´e au printemps poursuit sa croissance apre`s le passage du rouleau a`lames, alors qu'il y a destruction de la gesse cultive´e et de la lentille.Mots clé s: Rouleau a`lames, engrais vert, vesce velue, non-travail du sol, agriculture biologique Abbreviation: GM, green manure Can.