Farmers save money with 'green manure'
If you go
What: Soil quality field day hosted by the UW Extension and the UW-Madison Nutrient and Pest Management Program.
When: 10 a.m. to 2 p.m. Wednesday
Where: The Rock County Farm on Highway 14, a quarter mile east of Highway 51
Cost: $10, which includes the cost of lunch and materials.
RSVP: Call (608) 757-5696 by Tuesday.
CENTER TOWNSHIP New technology has breathed life and significant cost savings back into an old farming practice.
One Rock County farmer is tickled pink with the results.
This spring, Dan Pakes inter-seeded red clover into his winter wheat crop on two fields in Center Township between Janesville and Evansville. The wheat has been harvested, and what's left is a thick, green crop of fertilizer.
"You're using the old practice combined with new technology to get a significant cost savings," Pakes said.
Commonly called "green manure," red clover and other legumes were used as a nitrogen-producing cover crop until World War II when commercial fertilizer production became common, said Jim Stute, UW Extension crops and soils agent.
In the last few years, the cost of commercial fertilizer has skyrocketed, making the green method practical, he said.
The UW Extension has worked this summer to figure out exactly how practical, Stute said. Extension researchers have been running fertilizer response trials to compare the way crops grow at levels of applied fertilizer from zero to 200 pounds per acre, Stute said.
A typical Rock County farmer would apply 130 to 150 pounds of nitrogen per acre of corn, Pakes said.
Research has shown that a crop of red clover provides about two-thirds of the nitrogen a corn crop would need. But that research is old, and the number could be higher, Stute said.
Pakes figures he'll get 80 pounds of nitrogen per acre from his red clover. At about $1 per pound for commercial fertilizer, the savings add up.
While researchers work on the numbers, Pakes already is adamant that corn thrives on natural fertilizer.
"You can almost always bank on a high corn yield following red clover," Pakes said. "You can put on 100 pounds of commercial fertilizer, and I can show you night and day difference. I'm going to have a deeper green, like a John Deere green. The corn is like a Christmas tree color. The commercial nitrogen, even at the same rate, will not out-perform naturally grown nitrogen, even under the same circumstances."
Farmers aren't the only people who benefit from red clover plantings, Stute said.
Clover does better at preventing soil erosion than wheat stubble, Stute said. That helps keep lakes and streams clean, he said.
One acre of red clover sequesters seven tons of carbon dioxide, Stute said.
And growing fertilizer uses far less energy than commercial production, Stute said.
Plus, the clover uses the solar power that wheat fields often miss out on.
Winter wheat is planted in October. It germinates in the late fall and goes dormant until mid-spring, Stute said.
It's harvested in July. So those fields sit empty, missing out on lots of late-summer heat, Stute said.
Red clover can be planted in the spring at the same time farmers typically fertilize their winter wheat.
The trick is to spread the seeds, which are barely visible to the eye—when frost covers the ground and melts daily, Pakes said. The frost cracks the ground open for the seeds and melts them into the soil.
The small clover seedlings can tolerate the low light under the wheat. When the wheat crop starts to dry out for a July harvest, the clover takes off, Stute said.
In August and September, the clover soaks up the late summer sun in what would have otherwise been a field of weeds, Pakes said.
"The clover is so nice and thick it drowns out just about everything," Pakes said. "It keeps the weeds down."