Cover crops help your soil survive drought conditions
One of the biggest issues for farmers in areas where drought can be a ever-present problem — like most of Kansas — has been how summer cover crops perform, and what kind of moisture they take out of the soil profile when the weather turns hot and dry.
The summer of 2011 provided Ryan Speer, co-owner of Jacob Farm near Sedgwick in south-central Kansas, a great chance to test some theories, he told attendees of the Jan. 24-25 No-till on the Plains annual winter conference in Salina.
Jacob Farm has been a continuous no-till operation for 12 years. Normal rainfall is 30 inches per year. In 2011, just over 16 inches fell. Fifty-five days saw temperatures above 100 degrees F.
• Cover crops are even more valuable during times of drought.
• Cover crops keep soil cooler, provide forage for livestock.
• In drought, the water profile was better in fields with a growing cover crop.
A typical rotation on the farm for irrigated land is corn, corn, soybean, wheat, double-crop soybean — with rye and radishes for a cover crop after the second corn crop.
For dryland fields, the rotation is corn, soybean, wheat, double-crop milo — or soybeans with rye and radishes as a cover crop after corn. The concern for Speer, as it is for most farmers, was how much water the cover crop might use, making it no longer available for a production crop in the next cycle.
What he learned was surprising. The immense root system of the rye and radish crop and the dense aboveground foliage actually cooled the soil, preventing evaporative loss to a greater extent than the water-stingy growing crop used from the profile. In addition, the cover crop suppressed weeds that otherwise might have sprung up to deplete the water supply.
“What we saw was a better water profile behind the cover crop,” he said. In addition, he said, the cover crop could be harvested to provide food for livestock in a time when all forages are in high demand. Speer said the ongoing plan for the Jacob Farm is to continue cover-crop blends in search of the perfect forage crop. One crop currently on the radar screen, he said, is black oats, which are said to be a high-quality forage crop.
Overall, Speer said, no-till has proven to be a good system for the farm where he has worked for 10 years, first as a farm manager and now as an operator and co-owner.
He said no-till was originally adopted as a method of soil erosion control, labor savings, moisture conservation and ability to intensify rotations. Yields have increased steadily with years in the program, he said, and less irrigation is needed to maintain yield.
TALKING COVER: Ryan Speer, co-owner of Jacob Farm, says his experience shows that cover crops actually improve the soil’s water profile during times of drought.
This article published in the March, 2012 edition of KANSAS FARMER.