Grazing improves ag sustainability (commentary)

Published on: April 23, 2012

*Jesse Bussard is an agricultural journalist and blogger, forage agronomist and animal scientist. Bussard is studying forages and livestock grazing systems while working on her master's degree in crop science at the University of Kentucky in Lexington. She is a native of Pennsylvania and a fifth-generation agriculturalist with a passion for agriculture and the beef cattle community. Learn more about Bussard on her blog "Pearl Snaps' Ponderings," and follow her on Facebook and Twitter. She can be contacted at pearlsnapsponderings@gmail.com.

SOME of the most environmentally conscious people I know are livestock farmers and ranchers.

Through various stewardship practices, they ensure that the land they live on will continue to flourish and thrive for years to come, providing grazing for their livestock and habitat for countless species of wildlife.

Currently, an estimated 587 million acres of permanent grassland, pasture and rangeland are used for livestock grazing across the U.S. Much of this land is unsuitable for growing crops for many reasons, e.g., it is rocky, steep terrain or has marginal soil quality. However, it provides suitable forage plants like grasses and forbs that can be grazed by livestock.

By having the ability to graze this land, farmers and ranchers are able to more than double the land area for producing food.

In my graduate studies, I have made it my focus to better understand these livestock grazing systems and, in turn, find ways to help farmers and ranchers improve upon them.

Many times, the importance of the relationship among the grazing animal, the forage plants being grazed and the soil supporting the forage goes overlooked. This key relationship, known as the plant/animal interface, creates a dynamic ecosystem in pastures and rangeland grazing systems.

As livestock graze a pasture, they affect forage composition, plant canopy structure and the growth rate of the forage. These changes in the pasture forage, in turn, affect the animals' grazing behavior and their ability to obtain their needed supply of nutrients.

To manage this system properly, farmers and ranchers must not only understand the livestock's nutritional needs and grazing behavior but also the unique physiology and growth requirements of the plants.

Grazing animals require nutrients for maintenance energy needs, growth and development, milk production and fetal growth and development. The challenge of the livestock manager is to leave enough pasture forage after grazing to maintain some leaf tissue for light interception to generate energy for above- and below-ground growth.

To maintain this balance, livestock farmers have developed many different types of grazing systems. Some are continuous, where cattle graze for indefinite periods of time; others are rotational, where cattle are moved from one grazing area to the next.

Grazing systems vary on each farm and geographic region and are tailored to meet the needs of each particular livestock species and the forages present.

Each system has its own set of advantages and disadvantages. The more intensive or highly managed a grazing system, the more inputs and labor required.

Intensive rotational grazing systems are favored over continuous as they improve sustainability by maintaining pasture condition and preventing overgrazing, and through the closer management scheme, farmers are able to keep a more watchful eye on their animals.

Pastures are a dynamic ecosystem. By utilizing grazing systems on America's pastures and rangelands, farmers and ranchers help to keep this ecosystem in balance.

The relationship that exists between the cow and the grass is very similar to that of the wild buffalo or elk that once roamed America's grasslands.

If animals were grazed too long on a particular location, plants would become vulnerable to environmental stresses. At the same time, without the presence of grazing animals to consume forages, overgrowth would die and could promote fires and desertification. Each needs the other to keep it in check.

This sustainable practice helps to maintain plant biodiversity and wildlife habitat and prevent the encroachment of invasive weeds, all while allowing farmers and ranchers to continue to produce food for the nation on land that may not otherwise be suitable for agricultural production.

Volume:84 Issue:17

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