Some people wonder: since there is already nitrogen in the soil, why do farmers need to add it?
It comes down to the fundamentals of plant physiology. Plant power depends on nitrogen.
“Nitrogen plays a role in chlorophyll formation — the greenness in plants — which allows them to absorb sunlight more effectively. Chlorophyll is a plant’s energy manufacturing system,” said Warren Formo, executive director of the Minnesota Agricultural Water Resource Center (MAWRC), a nonprofit that assists Minnesota farmers in addressing water issues.
For the past seven years MAWRC, Minnesota Corn, and University of Minnesota Extension have partnered to bring farmers the latest and best science on the proper use of nitrogen in agriculture. University of Minnesota Extension presents that information in a series of seminars called Nitrogen Smart, which are offered in-person in January, February, and March. Farmers can also attend online.
So, nitrogen is vital to a plant’s energy. But when it comes to corn and other grains, the need for feeding goes beyond green power. Nitrogen also helps make corn into a superfood — that is, in addition to oils and starch for energy, grain also has protein for building muscle and maintaining a healthy body.
“Nitrogen is a basic building block of protein,” Formo said. “We want to produce grains with protein because that’s a human food need. It’s also an essential for feeding livestock. To raise corn that works as food, and as feed, you want that high protein. If you look at the chemistry of it, nitrogen makes up about 15 percent of a protein molecule. If you are going to grow a corn crop that is 8.5 percent protein, you need to feed that crop the right amount of nitrogen. To produce a bushel of corn (56 pounds), therefore, you need a little more 7/10 of a pound of nitrogen.”
The interests of successful farming and environmental protection converge in the science of nitrogen. By learning how to make sure that the crops get the right amount of nitrogen, in the right form, at the right time, and at the correct rate, farmers also do their best to prevent what they apply from draining away in surface or groundwater. Nitrogen Smart covers these methods, known as precision agriculture. Not every acre is the same. Differences in soil from field to field, and differences in climate in the different regions of Minnesota, mean that one nitrogen recommendation doesn’t fit every farm. This is a continually developing science. Nitrogen Smart covers this. And among the latest means to use nitrogen effectively and efficiently as a plant nutrient, there are a growing array of products a farmer can add — microbial treatments that enhance soil health and help the crop use the nitrogen more effectively; and stabilizers that help keep the nitrogen in place in the soil until the crop needs it — Nitrogen Smart also covers these helpful products.
Maximizing corn yield in Minnesota can be part of a global view of environmental protection, according to Formo.
“Minnesota farmers are achieving an average yield close to 200 bushels of corn per acre, and in some places, farmers are growing 300 bushels,” Formo noted. “Why is it important for Minnesota corn farmers to push that envelope? By growing this food crop here, on these incredibly rich soils that we have, we are doing our part to feed the world. If, through inefficiency or some other reason, we don’t produce as much food as we can on these good farming lands, then that shifts the pressure to raise that food elsewhere, to other regions that may be ecologically sensitive, where the land is better used as wildlife habitat, or in other cases, they might be forced to raise food on land that is better suited or more desirable as a place to live. So, when we use nitrogen responsibly, as part of farming responsibly, it’s part of being the best stewards of the planet that we can be.”
