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ARS Home » Midwest Area » Lexington, Kentucky » Forage-animal Production Research » Research » Publications at this Location » Publication #335019

Research Project: Optimizing the Biology of the Animal-Plant Interface for Improved Sustainability of Forage-Based Animal Enterprises

Location: Forage-animal Production Research

Title: From the lab bench: Mixtures of grasses and legumes for extending the grazing season

Author
item Aiken, Glen

Submitted to: Cow Country News
Publication Type: Popular Publication
Publication Acceptance Date: 9/12/2016
Publication Date: 10/1/2016
Citation: Aiken, G.E. 2016. From the lab bench: Mixtures of grasses and legumes for extending the grazing season. Cow Country News. Pgs 70-71.

Interpretive Summary: Clovers and warm-season legumes, such as alfalfa and birdsfoot trefoil, in mixture with grasses can enhance the overall nutritive value of the overall forage, increase dry matter yield, and contribute nitrogen to the soil via the nitrogen fixing bacteria that colonize in the root systems of legumes. There are two primary sources of nitrogen from legumes; from when part of the root system or aboveground plant dies and decomposes, which is a very slow process, or by the animal consuming the legume and excreting the excess nitrogen via manure or urine. Therefore, nitrogen excreted by animals consuming legumes is the most efficient method for legumes to contribute to the soil nitrogen. Healthy and productive grass stands when combined with legumes will have a better chance of generating rapid growth in the early spring and extending productive grass growth into the late fall. This information can be helpful to cattle producers that want to maintain strong grass-legume mixtures that can generate more growth in the late fall for extension of the grazing season.

Technical Abstract: A column was written to discuss how clovers and warm-season legumes, such as alfalfa and birdsfoot trefoil, in mixture with grasses can enhance the overall nutritive value of the overall forage, increase dry matter yield, and contribute nitrogen to the soil via the nitrogen fixing Rhizobia bacteria that colonize in the root systems. Legumes added to grasses can tighten the spatial distribution of plants for improved control of soil erosion and nutrient runoff, and contribute protein to the diet that are above cattle requirements for protein. There are two primary sources of nitrogen from legumes; from when part of the root system or aboveground plant dies and decomposes, which is a very slow process, or by the animal consuming the legume and excreting the excess nitrogen via manure or urine. It seems logical that the most efficient way to transfer legume nitrogen to the soil is through the animal. Maintaining high percentages of legumes in mixture with grass can benefit soil nitrogen status and maintain productive grass stands with the widest possible growing season.