Farm and Forest Field Day at Lawson's Farm
Field Day at Thomas & Debra Lawson's Farm
Thomas and Debra Lawson's 80-cow dairy farm is on Little Pine Creek [map] at the south end of the Bryant watershed where Bryant Creek joins the North Fork. It's just a few miles above Norfork Lake, which is popular for fishing. The Lawsons work hard to make their farm more successful. They are also mindful of how their farming practices affect the creek.
On October 13, 2000, they invited farmers and other interested people to see how they were doing this. This event was part of a Field Day hosted by the Bryant Creek Demonstration Project.
Cows produce a lot of manure. Manure is a good fertilizer
for the soil, but in the creek, it's too much of a good thing. Water plants
grow wildly, and then decay, using up oxygen so fish can't breathe. It
also feeds bacteria that are harmful to fish and other water creatures.
The Lawsons know that if too much manure builds upon any one part of the
pasture, the runoff after a rain can wash some of it into the creek.
What's the trick to preventing harm to the creek from manure? Keep those cows moving! The Lawsons use electric fences to divide the pastures into small plots. Thomas said he uses electric fencing because it is easier to put up, or to move when needed, than barbed wire fencing.
They move the cows to a new grazing area every day of the
week. This gives the cows a clean, fresh meal of grass, and stops manure
from building up in one place. It gives the grass in each area a week
to grow back before the cows come back to graze on it again. By being
walked on less often, the grass grows faster. And growing more grass means
buying less feed.
Also, when it rains hard, more manure particles are trapped in the stems and leaves of the thick pasture grass. Too much manure and grass that's trampled flat means that some manure will reach the stream. When manure is more evenly scattered, there is less to wash off, and more grass to catch it. The result: Less manure can reach the creek.
The Lawsons' dairy barn sits on a hillside above Little Pine Creek, and that was another problem. Manure that collected there could pose a real danger to the creek and its wild residents.
Cows produce manure wherever they are standing. They stand in a holding pen while waiting to be milked. They stand and wait in the milking parlor while they are being milked. They stand and feed from troughs outside after milking is finished. Thomas said he used to collect the manure from these areas and pile it up nearby. When he got a chance, he'd spread it on the pastures to fertilize the grass. Often, especially in bad weather, the pile got very large before he could spread it. The more that collected, and the longer it was there, the more likely it was that some would end up in the creek.
Now that the plots are fenced and the pasture rotation is underway, it's time to solve this problem as well. The Lawsons plan to pave all parts of the milking area. This includes the holding pens, the milking parlor, and the area around the troughs. The paved areas will be hosed down every day, and the wash water will flow through an 8-inch diameter pipe to a lagoon just down the hill.
There, manure will settle out of the wash water, and sunlight
and bacteria will act on it and make it cleaner. Soon, water from the
surface of the lagoon will be clean enough to re-use. It will be pumped
back up the hill into a holding tank. Another pump will move it from the
holding tank up to the dairy barn. The same water will be used again and
again to clean the milking area.
What happens when the manure builds up in the lagoon? Once a year, a large pump with a flexible hose will be used to vacuum the lagoon. The "effluent" will be pumped into a large mobile sprinkler called a "traveling gun." The Lawsons will spray the liquid manure over their pastures. It's still true that too much manure can be a problem. But the right amount is fertilizer the Lawsons don't have to buy.
This manure lagoon system is not yet finished. Maybe next year we can visit the Lawsons again and take more pictures of the completed system.
Keeping cows out of the creek keeps them from breaking down
its banks. It also keeps them from depositing manure in the water. But
they must have other places to drink. The Lawsons made a drinking trough
and filled it with water from a small spring nearby. Perforated pipe planted
in the wet area made by the seeping water connects to the trough. The
past two years, though, dry weather has left the trough, which was always
full, standing empty. Ponds make up for the loss.
Link: This page has a clear non-technical discussion,
with excellent diagrams, of the nutrient content and value of dairy manure.