ROCK SPRINGS, Pa. — Although sustainable ag proponents didn’t exactly fill a bus the Thursday afternoon of Penn State’s annual Ag Progress Days, the half-dozen farm folks who did tour the university’s dairy cropping and organic pest management plots brought a truckload of questions along to the field. Or fields, to be exact.
The two studies employ 192 intensively studied quarter-acre plots where just about any measurement you could imagine being taken is taken — bad bugs, good bugs, crop yields, rainfall, erosion, tilth, soil fertility and more.
Glenna Malcolm, a postdoctoral student in the College of Agricultural Sciences, is manager of a decadelong — she hopes — project to study and evaluate the pluses and minuses that go along with a sustainable dairy cropping system designed to produce forage, feed and fuel for a typical Pennsylvania dairy farm with 65 cows and 240 acres.
Funding for the project comes primarily from a USDA SARE (Sustainable Agricultural Research and Education) grant that comes up for renewal every few years. Funds also come from the university and USDA’s Agricultural Research Service and Natural Resources Conservation Service.
On the bus ride from the Ag Progress site to the research plots, Malcolm told the visitors that the dairy cropping system study wasn’t conventional farming and wasn’t organic, but was somewhere in between — middle-of-the road agriculture, she called it, part of a growing discipline called “agroecology.”
Malcolm said she and her fellow team members — there are 36 of them, 14 faculty, six grad students, plus technical support staff and undergraduate assistants — recognize that theirs is a long-haul project.
The question they are trying to answer is, “Can a dairy farmer minimize inputs like fossil fuel, fertilizer and herbicides, be kinder to the environment, and still operate a profitable business with healthy, well-nourished cows? With the emphasis on profitable?” she said.
Finding the answer will entail collecting data over many growing seasons.
“A lot of the benefits you see from minimizing inputs — fuel, fertilizer, herbicides, limited tillage — don’t show up in two or three years,” Malcolm said.
“And it takes a long time to build up soil organic matter if you switch from conventional to sustainable methods,” she said.
“Do we have a profitable farm every year or just seven years out of nine?” Malcolm said. “What are the economic risks and are they acceptable?”
After the group arrived at the study’s test plots, Malcolm talked about crop rotation, weed control and the 65-cow virtual dairy herd the research group is using to check their results.
The cows are represented in a computer simulation program. The nutritional values for crops grown the test plots are fed into the computer, which calculates milk output and manure production from many different feeding scenarios.
The real-world crops are grown with actual manure from a nearby dairy farm, with application rates determined by the computer software. Application rates may be affected at times by the farmer, who may be spreading manure on his own fields when the research group wants it for their test plots.
The virtual cows get a complete diet, which includes one ingredient you don’t find in every feed bin — canola meal, which is what’s left after canola seed is pressed to capture its oil.
The oil, which is used as fuel, comes straight from a small expeller press on the Penn State campus and goes directly into the fuel tank of the modified New Holland tractor.
Soy oil would also work, but it gets too thick to power the tractor in cold weather. Canola oil can be used later in the season and is thought to be kinder to the tractor’s engine.
Malcolm said researchers estimate that 40 acres of canola could produce all the tractor fuel for their 240-acre farm.
Douglas Beegle, a soil scientist with the university, said the manure is applied at a rate of 23 tons to the acre in the spring and fall. Fall spreading goes on canola ground, while the spring application goes on before corn. Planting is done about two weeks after the manure is applied.
Because low tillage is part of the sustainable approach, manure is applied using a low-disturbance shallow disk injector that puts the liquid about 6 inches below the surface.
Weed control is a big concern with both the sustainable and organic approaches to cropping, and William Curran, a Penn State weed scientist talked about both.
Curran said the university started an organic research project eight years ago. It took three years before the land in the study could be certified organic, and in the five years since then researchers have been working on ways to control weeds.
One tool is the moldboard plow, which does an effective job of burying weed seeds so deep they can’t germinate.
Another, a reduced tillage approach, involves a cover crop cocktail that relies on observation and rotation to keep weeds in check.
Curran and other Penn State scientists are part of a nationwide study into weed and insect pest management in organic field crops. Their Reduced-tillage Organic Systems Experiment — ROSE for short — has participants in Maryland, Delaware, North Carolina and Oregon. Accounts of their experiences can be found online by searching for Penn State ROSE Review.
Maggie Douglas, a graduate entomology student, talked to the group about her work on insect control. With no recourse to insecticides, organic producers have to depend on a certain amount of luck and, to a large extent, on beneficial insects and spiders that eat bugs that aren’t so beneficial.
The project has a Web page to describe the many facets of the work that’s going on in the test plots at cropsoil.psu.edu/research/cropping-systems.