Milking cows in the Chesapeake Bay watershed means this Pennsylvania dairy must do everything it can to reduce its environmental load.
Perhaps no other dairy farmers in the country have been under as much environmental scrutiny and pressure as those in the Chesapeake Bay watershed in Pennsylvania and Maryland.
Alfred Wanner and sons Matt and John, Narvon, Pa., have geared much of their dairy and farm management over the past decade to stay in compliance with environmental regulations and nutrient loading limits. But in another sense, this farm has worked to be sustainable since the Wanner family bought the land 174 years ago.
Like other farms in the area, the land was originally deeded to William Penn. Seven Wanner generations later, the farm has grown to 750 acres supporting nearly 1,500 head of cattle. It supports three family farm owners plus nine full-time employees. If that’s not sustainable, I’m not sure what is.
But farming and milking cows in the Chesapeake Bay watershed means the Wanners must do everything they can to reduce environmental load. They’re first serious efforts began a decade ago, when they built their second freestall barn. “When we built that barn, we were looking for what we could do to be more environmentally friendly. We knew we needed to be proactive,” says Alfred.
After a lot of research, they decided to install a methane digester in 2006. The digester is an 80’ diameter, 16’ deep covered vessel. It is surrounded by heating coils to keep the digester at 100° to 101°F to keep the digester working throughout the year. Methane produced is then piped to a Cat engine to produce electricity.
The entire installation approached $1 million in capital outlay. Through various grants, the out-of-pocket costs to the Wanners were about $400,000, with an estimated payback of eight to 10 years. The Wanners are generating about $5,000 in electrical cost offsets per month. And because they use the manure solids produced by the system for bedding, they’re saving close to $40,000 a year in bedding costs.
In addition, the system reduces the amount of manure that needs to be hauled to fields because virtually all of the solids have been removed. And the nutrients in the liquid effluent coming off the system are typically available to crops the year of application. (Nutrients from undigested dairy manure, because of the high fiber content, typically become available to plants over a two-year period.)
Wanners have also gone to double cropping rye and triticale on a portion of their land. That allows them to apply double the amount of liquid effluent from the digester on that ground, gaining them better nutrient use and more feed.
The system hasn’t been without hiccups. Alfred says they were on pace to get a full return on their capital investment last year. Along with other repairs, the engine had to be rebuilt and the radiator had to be replaced. “Now, if everything keeps working, we should be able to get payback in 10 years,” he says.
But there’s been another benefit to the system as well. The bedding solids, even though they are not composted and only 30% dry matter, have less than a third of the bacterial load of the kiln dried wood shavings the Wanners had been using. “We also have much less Klebsiella bacteria,” says Matt. Somatic cell counts average138,000 cells/ml on a tank average of 90 lb./cow/day.
At the Wanner dairy, it’s clear environmental sustainability comes in many forms—some never expected nor anticipated.
The Wanners were a featured Virtual Farm Tour here at World Dairy Expo Friday. The tour was sponsored by Quality Liquid Feeds.
The Wanner Family