Soil fertility and weed control by sheep
July 2, 2010. Yesterday was a milestone for Mesa Winds Farm. Our diligent and hard-working “Young Farmers” Becky, Lindsay, and Trevor, completed the first-pass pruning of our vineyards. This is the first year that we didn’t have to resort to contract workers to get the job done. They proved, “Yes, we can”. We celebrated their hard work with a mostly-local, all-organic barbeque of ribs, potatoes au gratin, baked beans, salad, and rhubarb cherry crisp.
On the web site, Max has introduced you to our Babydoll Southdown sheep. In addition to cute, and their traditional roles as wool and meat providers, they will also play an important role in maintaining soil fertility and controlling weeds and cover crops in our vineyards. But why won’t they eat the grape leaves, we ask? So, while our young farmers sweated-out the last rows in the Pinot Gris, Max and I have been working with our CSU Extension Agent, Robbie Baird Levalley, to train the sheep what NOT to eat.
The protocol for this training was developed by Dr Fred Provenza of Utah State University and has been applied in vineyards on the West coast. Robbie has successfully applied it to a flock of Babydolls on a vineyard in Palisade, CO. So we are not exactly pioneers in this: We hold the ewes off feed overnight and then present them with fresh grape leaves, which they are happy to eat. We then give them a pill of lithium chloride that gives them a stomachache – which they associate with having eaten the grape leaves. On the second morning of this regime, most of them declined the grape leaves; those who ate were treated again. Later we turned them out into a vineyard. Those who ate grapes were removed for further conditioning; it is important that they not teach the others that its OK to eat leaves.
Yesterday we had remarkable success: only the ram, Louie, continued to eat leaves in the corral. He was left behind when we turned the others out to the vineyard. Most of the sheep ate grass and weeds around the grape plants without bothering the leaves; a few tested the grapes but went back to the grasses. Only two ewes and a lamb required further conditioning. Today we’ll do it again.
A “heritage breed”, Babydoll Southdowns are the breed of choice for this work because of their diminutive size which allows them to move about between rows and under the trellis wires. They seem intelligent enough to readily grasp this training and, in addition, they are known for their excellent quality fleece, comparable to Merino, and for delicious meat. We are very excited by this addition to our agro-ecology.