If you had to scavenge for food from Thanksgiving to Easter, chances are you wouldn’t be very productive and may not survive. The same is true of soil microbes.
They need living roots year-round to survive and thrive, which they don’t get in a traditional corn-soybean rotation. Planting cover crops puts live roots in the soil and food on a microbe’s table for more months of the year.
This is especially critical when transitioning to no-till, says James Hoorman, Ohio State University cover crops and water quality expert.
“The reason corn yields suffer when switching from conventional management to no-till is largely a result of compacted soils,” Hoorman explains. “In compacted, heavy clay soils, we can lose 40% to 60% of available nitrogen to denitrification, which occurs when we have standing water and poorly drained soil.”
Fungus and other soil microbes help build soil structure, remedy compaction and, in turn, greatly improve nitrogen availability. But, Hoorman says, conventional tillage promotes systems dominated by bacteria, so no-tillers need to rebuild beneficial microbes.
Rebuilding microbe populations takes time, but in the interim, some cover crops can help alleviate compaction in just one season.
“Cereal rye roots reach down 18 to 24 inches, easily pushing through tillage pans and loosening up soils in just 1 year,” says Michael Plumer, University of Illinois natural resource management educator. “Soils softened by fall and winter moisture allow the cover-crop roots to penetrate compacted layers more easily.”
In the drier conditions that corn…