Grazing

Grazing is a method of feeding in which a herbivore feeds on plants such as grasses, or other multicellular organisms such as algae. In agriculture, grazing is one method used whereby domestic livestock are used to convert grass and other forage into meat, milk and other products.Grazing is a method of feeding in which a herbivore feeds on plants such as grasses, or other multicellular organisms such as algae.The use of livestock grazing can be dated back to the Civil War. During this time land ownership was not common, and ranchers grazed their cattle on the surrounding, often federal, land. Not having a permanent home, these cowboys would frequently graze an area down, and then continue on their way. More commonly, however, cattle were rotated between summer and winter ranges. Soon the public saw how profitable cattle could be, and many tried to get into the cattle business. With the appearance of free, unlimited grass and feed, the land became overcrowded and the forage rapidly depleted. Ranchers tried to put a stop to this by using barbed wire fences to barricade their land, water sources, and cattle. After failed attempts, the Taylor Grazing Act was enacted in 1934. This act was put into place to help regulate the use of public land for grazing purposes and allotted ranchers certain paddocks of land. Additionally, 'fees collected for grazing livestock on public lands was returned to the appropriate grazing district to be used for range improvements'. The Taylor Grazing Act helped to stabilize ranchers' operations and allow them to continue raising their livestock.In the 19th century, grazing techniques were virtually non-existent. Pastures would be grazed for long periods of time, with no rest in between. This led to overgrazing, and was detrimental to the land, wildlife, and livestock producers. Today, ranchers and range science researchers have developed grazing systems to help improve the forage production for livestock, while still being beneficial to the land.A number of ecological effects derive from grazing, and these may be either positive or negative. Negative effects of grazing include increased soil erosion, adverse water quality impacts from increased runoff and loss of biodiversity. For example, historical grazing, along with other land conversion, in northern and central California has reduced native chaparral and forest lands by approximately 70 percent. Ongoing grazing expansion {and land conversion} driven by human population growth in this region threatens the remaining integrity of California chaparral and woodlands habitat in this region. In some habitats, appropriate levels of grazing may be effective in restoring or maintaining native grass and herb diversity in rangeland that has been disturbed by overgrazing, lack of grazing (such as by the removal of wild grazing animals), or by other human disturbance. Conservation grazing is the use of domestic livestock to manage such habitats, often to replicate the ecological effects of the wild relatives of livestock, or those of other species now absent or extinct. For example, heathland in Europe requires grazing by cattle, sheep or other grazers to maintain its structure and diversity.By utilizing grazing systems, livestock production has the potential to be maximized. The Cattlemen's Beefboard claims that 'approximately 85 percent of U.S. grazing lands are unsuitable for producing crops. Grazing animals on this land more than doubles the area that can be used to produce food. Cattle serve a valuable role in the ecosystem by converting the forages humans cannot consume into a nutrient-dense food', but there is no scientific evidence which substantiates this claim.Grazing occupies 26 percent of the Earth's terrestrial surface, while feed crop production requires about a third of all arable land. Expansion of grazing land for livestock is a key factor in deforestation, especially in Latin America: some 70 percent of previously forested land in the Amazon is used as pasture, and feed crops cover a large part of the reminder. About 70 percent of all grazing land in dry areas is considered degraded, mostly because of overgrazing, compaction and erosion attributable to livestock activity.Cattle destroy native vegetation, damage soils and stream banks, and contaminate waterways with fecal waste. After decades of livestock grazing, once-lush streams and riparian forests have been reduced to flat, dry wastelands; once-rich topsoil has been turned to dust, causing soil erosion, stream sedimentation and wholesale elimination of some aquatic habitatsIn North American tallgrass prairies, diversity and productivity are controlled to a large extent by nitrogen availability…Nitrogen availability in prairies was driven by interactions between frequency of fires and grazing by large herbivores…Spring fires enhance growth of certain grasses, and herbivores such as bison preferentially graze these grasses, keeping a system of checks and balances working properly, and allowing many plant species to flourish.Grazing management has two overall goals, each of which is multifaceted:  Media related to Grazing at Wikimedia Commons