Protecting soil is important
By Janet Kubat Willette
Date Modified: 10/16/2012 2:13 PM
GOODHUE, Minn. — Top producers manage their topsoil, an NRCS soil scientist told a small group gathered for a Nutrient Management Field Day.
Doug Miller, a soil scientist for the Natural Resources Conservation Service, was one of several speakers at the event, held on the Ed McNamara farm near Goodhue on Sept. 19.
Topsoil is the most important part of the soil, Miller said, and it is the soil that is most susceptible to wind and water erosion.
This year brought some of the worst erosion he's seen in his 35 years of working in the field of soils. He passed around pictures showing horizons filled with blowing dirt.
Fields were overplowed and overworked in the fall, Miller said, and worked again in the spring. All the tillage left the soil with little residue to protect it when heavy rains fell in the spring and strong winds blew. Dollars left with the topsoil.
The same scenario could play out this fall and next spring because crops are coming off early and tillage has already been completed in some areas.
Soil could be exposed for seven or eight months, Miller said.
"You need to protect your topsoil so it doesn't get hit by the elements," he said.
One of the ways to protect topsoil is planting cover crops.
The Minnesota Department of Agriculture and University of Minnesota have done and continue to do cover crop research. Funding may also be available from the Natural Resources Conservation Service for cover crop planting.
Jill Sackett, a University of Minnesota Extension educator with Rural Advantage, helped set up an online Cover Crop Decision tool. The tool can be found at www.mccc.msu.edu.
It is designed to help growers select the right cover crops for their rotation and for their purpose or need.
Some cover crops provide nitrogen and cover crops that scavenge nitrogen, Sackett said. There are both benefits and drawbacks to cover crops, she said.
Cover crops grown in Minnesota include winter rye, different clovers and more recently, tillage radish. She works with one producer who plants a
mixture of field peas, oats and tillage radish after his small grains with much success.
It will be difficult to get rye seed this year, said Gene Werner of Werner Seeds in Dundas. Farmers are turning away from small grains and growing
corn instead because it's more profitable.
Having living roots in the soil year-round has benefits below ground level, too, Miller said. It gives the micro-organisms that live in the soil something to feed on. Those micro-organisms secrete a substance commonly referred to as soil glue that improves soil structure.
There are more than 6 billion micro-organisms in a cup of topsoil from south central Minnesota, he said.
"Dirt is not dead, it's quite alive."