As farmers across the region get ready to start spring planting, many have concerns about soil moisture this year.
According to the U.S. Drought Monitor, extreme drought conditions have expanded in central to northeastern Montana, while dry conditions continue in western North Dakota.
“By managing soil fertility, producers can lessen some of the ramifications of drought,” said Tryston Beyrer, the crop nutrition lead of Western North America for The Mosaic Company.
The chance for yield to increase in response to added fertilizer may be higher in a dry year than during a normal one, Beyrer added.
Plant development and maturity are also accelerated by high fertility levels, meaning the crop might get through critical flowering stages earlier.
If moisture is a limiting factor during the growing season, there is only so much management that can be done. But there are nutrients that can be applied to the soil that will help plants use water more efficiently.
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Beyrer recommends every farmer conduct a complete soil test to identify any limiting nutrients before making applications.
“Identifying and correcting soils that are deficient in nutrients can help provide balanced fertility to plants so they can utilize water more efficiently,” he said.
Beyrer recommends that if there are nutrients that are deficient on soil tests, to correct those nutrients right away, because plant nutrition has a lot to do with yield.
“As much as 60 percent of crop yield comes from plant nutrition,” he said.
While soil tests are effective at identifying nutrients likely to be deficient, Beyrer cautions that soil tests taken in a dry year look different than those taken in a year with adequate nutrition.
“It is better to use a combination of soil tests identifying low nutrients and four-year soil test trends and crop nutrient removal values to determine crop nutrition needs.
The University of Minnesota (and other universities) have recognized that on average, soil test nutrient levels should be in the “optimum” category.
“In a dry year, having nutrients like potassium in a high category is desired because it allows a higher concentration of nutrients to get into the plant with less water,” Beyrer said.
Potassium is an essential nutrient required for plants to grow efficiently, especially under dry conditions.
The recommendation in a normal year for potassium is typically around 150-200 ppm (parts per million) or 300 pounds per acre, but in a dry year, that level should be raised to the “high” soil test category.
Beyrer explained that potassium will bind or fix in the soil as it dries out.
“By applying more potassium, it helps overcome some of that fixation or tie-up, and allows potassium to be taken up in the soil solution,” he said.
The nutrient that is most important for water movement within the plant is potassium. Like a water pump, potassium influences water potential within the plant, and moves water up and down within the plant.
“Potassium acts like antifreeze. In the winter, you have crops like alfalfa where potassium helps keep them from winter kill. In hot conditions, it acts like a coolant, just like antifreeze would do in a vehicle,” he said.
If plants are limited in potassium on the soil test, nitrogen uptake may be restricted, resulting in lower use efficiency.
“With more nitrates in the soil after last year’s drought, farmers may be able to reduce the amount of nitrogen they put on in 2022, as long as they have sufficient potassium in the soil,” Breyrer said.
When potassium levels are maintained at optimum agronomic levels, plants utilize nitrogen more efficiently and effectively, and more of the applied nitrogen is recovered in the above ground biomass.
In addition to potassium, other nutrients that should be in a “high” category to lessen the effect of drought on yield are nitrogen, phosphorus, and boron.
“Boron enters into the plant with water, but it is really important for pollen viability,” he said. “Studies are showing that in dry conditions, pollen can become less viable, and you would get less pods per plant on a soybean plant and less kernels on a wheat plant.”
Beyrer recommends applying boron to overcome pollen challenges and create greater efficiency of the uptake of other nutrients.
“Boron is not mobile within the plant, so the plant can’t remobilize it. It is important we get some boron into the soil in the root zone so the plant can continually take boron up all the way throughout the season,” he said.
If farmers wait to make corrective applications in-season, it may be too late, especially if there is a shortage of moisture to move boron into the root zone.
To make about 10 bushels of corn, or 3 bushels of soybeans, it takes about 1 inch of water on average.
“You want to make sure that soil fertility levels are built up enough that when water goes into the crop, the water takes the full amount of nutrients with it,” Beyrer said.
The weather was dry in 2021 and it is still looking dry in 2022 in those same regions.
“Mother Nature has a way of changing things in a heartbeat and growers should plan for success, especially if they are farming in the drought regions. Any additional crop that they can grow will be invaluable this year,” he said. “Water could be a limiting factor this year, but if we get moisture, make sure the next limiting requirements for plant growth are not limiting, such as crop nutrition or fertility.”
The Mosaic Company is a fertilizer company that mines for potash and phosphate. Some of its products include MicroEssentials, which uses phosphorus as the vehicle for delivery of essential nutrients.
A good product to use during drought is Aspire, which has 58 percent K2O and two forms of boron.
“Mosaic’s main mission is helping the world grow the food it needs by addressing nutrient concerns and crop growth productivity,” he said.
Those growers in Montana, North Dakota, and northern Minnesota, who want more information on Mosaic’s fertility products, can call Mosaic representative Sherry Koch, of Wahpeton, N.D., at 701-640-0162.
For more information, see https://www.mosaicco.com/.