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

Abstract

Forage mixtures containing legume out-yield monocultures, fix atmospheric N, and have lower C footprints. However, evidence-based information on creating forage mixtures by direct seeding legumes into existing pastures is limited and bloat-free legumes non-existent. Traditionally, pastures requiring improvement in western Canada were fully replaced by breaking up the old stand and re-seeding. 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.

Effect of Cultivated Pastures on Soil Bacterial Communities in the Karst Rocky Desertification Area

“…The relevant studies have shown that mixed pasture was more conducive to the accumulation of soil total nitrogen ( Yang et al, 2013 ). In addition, the biological nitrogen fixation of white clover in the LT treatment increased the nitrogen content ( Young et al, 2019 ), and Khatiwada et al (2020) believed that mixed pasture was relatively stable, with strong root activity, improved photosynthetic capacity, and strong soil microbial activity, which can improve nitrogen accumulation capacity. However, the total nitrogen content of NG was 0.94 ± 0.02 g.kg –1 in our study.…”

Growth Performance and Plasma Metabolites of Grazing Beef Cattle Backgrounded on Buffel or Buffel-Desmanthus Mixed Pastures

“…The presence of 11–33% legumes in temperate pastures was found to increase DM yield, but with a reduced yield benefit as the legume proportion increased to 67% or more [ 64 ]. Legumes increase pasture productivity by contributing to increased light capture compared to pure grass stands [ 65 ]. Furthermore, nitrogen-fixing legumes promote grass growth by providing nitrogen for the companion grass if moisture is not limiting [ 66 , 67 ].…”

Pasture rejuvenation using sainfoin and cicer milkvetch in western Canada

“…The pan drill (Fabro Mfg.) is a self‐propelled seeding implement that penetrates the soil by its weight and has been used by researchers in western Canada for forage establishment in clean and packed seedbeds (Khatiwada et al., 2020). Seeds were drilled in rows at a row spacing of 18 cm at all locations at a depth of 1.5 cm.…”