Daily News Archive
From May 10, 2002
Goats Provide a
Non-Toxic Alternative to Spraying Herbicides for Invasive Weeds
Ms. Lamming, who describes herself as a displaced cattle rancher, explains the role of her herd as more than a method of erradicating weeds, but as restoring a healthy ecoysytem. "The goal of the land is to build the soil so it can produce the kinds of plants that we want to grow there. What we need to be looking at is the water cycle, mineral cycle, energy flow and succession. Weeds are symptomatic of a problem. The problem is sometimes poor soil having no organic matter that cannot support good growth. We want to make the grass the best competitor and stress the weed at every turn. Goats help with this problem because everything they eat is then recycled as fertilizer and laid back down on the grasses. As the goats graze, they trample in the fertilizer."
Typically farmers, ranchers and other property owners rid their property of noxious weeds by using herbicides, often Tordon (picloram and 2,4-D) on it, which costs about $100 an acre. Aside from the health problems associated with herbicide use, there are many other problems. First, herbicides not only destroy the target weed, but often reduce a number of non-target plant species as well. In addition, herbicides can increase the toxic poisons, including potassium nitrate and cyanide, in some plants. These poisonous chemicals have been demonstrated to be toxic to livestock as well as wildlife, so increasingly the levels of these poisons is surely detrimental to the animals that live among these plants. Furthermore, some herbicide-tolerant plants may be physiologically affected by the herbicide. Ms. Lamming recalls seeing land in the West barren of any plant life except the diffuse knapweed the herbicides were intended to kill.
The first thing goats do when they walk through the pasture is snap off all the flower heads. Then they pick the leavesoff one at a time, very quickly, leaving a bare stock. Once the goats graze the weed, it cannot go to seed because it has no flower and it cannot photosynthesize to build a root system because it has no leaves. Grasses are their last choice, which means the desirable grass species are left behind with natural fertilizer to repopulate the land.
For more information on invasive weeds, visit Beyond Pesticides' Ecological Management of Invasive Weeds webpage. To learn more about grazing goats for weed control, read Successfully Controlling Noxious Weeds with Goats in the Resouces and Publications section.
Go Head to Head with Herbicides
"'People seemed to think this was a funny idea when it was first suggested," Mr. Luginbuhl told a reporter from the News and Observer. "But it's easy to see the goats are making a difference."
The 20 goats, which feed on just about anything, are being brought in as part of an experiment to compete with a nearby plot where conventional herbicides are being sprayed. The objective is to get rid of a non-native invasive species called kudzu that has choked the land and engulfed a creek that is now barely visible. The roots of the plant extent 15 feet into the ground and the stems are so thick in some areas that chainsaws are needed to get in to spray the herbicides.
The project is being funded by a federal grant of $287,500 and is expected to last two to three years. Over that time the goats will be rotated around roughly 700 yards in half-acre penned lots. Usually goats are able to strip a mile-long stretch of all biodiversity in about 30 days - but given the depth of the kudzu root more time will be needed. The idea is that the goats will continuously eat the leaves and vines of the plant, which will expose the root long enough so that it cannot replenish its leaves and eventually will die.
Mr. Luginbuhl, an associate professor of animal sciences and head of the Meat Goat and Forage Systems Research and Extension Program at NCSU, knows the important contribution goats can make toward stemming pollution and limiting the use of toxic chemicals in land management. Although the idea is not new it may be one of the first times a federal or state government has funded a goat-eating project to compete directly with herbicides to see which can better kill the aggressive plant.
For more stories
on goats as 'nature's lawnmowers, see:Alternative
Weed Strategies, Pesticides and You;