Management equally important for pastures as crops
It's time for farmers to put as much effort into managing their pastures as they do their crops. Presenters from the United States Department of Agriculture's National Resource Conservation Service and South Dakota State University Extension disc...
It's time for farmers to put as much effort into managing their pastures as they do their crops.
Presenters from the United States Department of Agriculture's National Resource Conservation Service and South Dakota State University Extension discussed the importance of soil health Tuesday at Dakotafest in Mitchell and recommended ranchers take better care of natural grasses when cattle are grazing.
"If that land base represents 50 percent of your land base, are you spending 50 percent of your effort thinking about that part of your operation?" asked Pete Bauman, a range field specialist for SDSU Extension in Watertown.
Bauman then recommended a "take half, leave half" approach to grazing, in which no more than 50 percent of plant growth should be removed during grazing, and at least 4 inches should be left above ground.
According to Stan Boltz, regional soil health specialist for NRCS, 30 to 50 percent of grass roots die annually.
With enough growth above the surface, roots can replenish fairly quickly, but when about 70 percent of growth is removed, plants suffer about 90 percent root reduction, Bauman said, which causes replenishment time to extend from about 30 days to 60 days or more.
"It takes grass to grow grass," Bauman said. "By only taking 50 percent, you have soil health above and root structure below. As we take more than that, you have an exponentially negative effect on the roots."
But that doesn't mean cows are eating 50 percent of pasture grasses. As grasses are trampled or damaged by insects, small mammals or defecation, Bauman recommended ranchers allow cattle to eat only about 25 percent of grass grown on pastures.
The pasture discussion was delivered in tandem with a rainfall simulator presentation, in which Bauman and Boltz set up bins of soil that had undergone various types of treatment. Some treatments included tilling, no tilling, cover-crop growth, overgrazed and properly grazed soil.
By then activating a shower head over the soil, which moved rapidly from side to side, the presenters simulated the effects of 2 inches of rainfall on various types of land.
"We get long periods of time without rain, and then we get the gully washers. This mimics that pretty well," Bauman said. "We put on 2 inches in 10 minutes, which sounds pretty intense, but it's not all that far off from what we're experiencing across the state."
Water collected in two jars for each soil sample to visualize runoff versus infiltration into the ground. The runoff jars for tilled soil and overgrazed land were nearly filled and were polluted with lost soil, while the runoff jars for the no-till and properly grazed soils were nearly empty and without much sediment.
Furthermore, when the till and no till bins were overturned, water breached the no-till soil through to the bottom, whereas the bottom of the tilled soil was dry and dusty.
"Tillage overall is detrimental to soil health ... For every inch of water that runs off, you basically lose 150 to 200 pounds per acre of production," Boltz said. "It's going to your neighbor's land or to the Missouri River. You're losing that in terms of real dollars and production."
Bauman called tilling "a triple-edged sword" that destroys worm and insect holes, doesn't allow water to infiltrate and causes soil loss.
Bauman also mentioned a misconception surrounding dams. Although landowners may be happy to see full dams immediately following rain, Bauman said that means the water was unable to soak into the ground, and it's more natural for the dam to fill slowly two or three days later.
"That delayed fill in dams is a good indicator that you're on track," he said.
The presenters also promoted cover crops, which showed levels of water retention on par with the no-till soil. Although the process may cost more up front, Bauman and Boltz said cover crops are a "real benefit" that kickstart healthy processes in the ground.
The presenters will remain on site throughout Dakotafest, and there are more discussions regarding management for range and pasture health scheduled at 10 a.m. today and Thursday in the SDSU Extension tent.