Cover crops offer a wide range of potential benefits for producers – better nutrient cycling, more weed suppression, more livestock forage, better soil structure, increased soil organic matter, and healthier soil microbial communities. To reap those benefits, producers need to make some careful decisions.
Those decisions start with the goal for the cover crop. Is it intended primarily to produce forage for livestock, provide weed suppression, or feed the soil? The answer to that question is the first piece of data needed, but it’s not the only one.
Another critical point to consider is how much moisture a producer expects to be available the following cash crops. If a cover crop uses too much moisture, it can affect the yield of a water-sensitive crop like corn in the following season.
Monitor soil moisture
Dan Forgey, longtime agronomy manager at Cronin Farms near Gettysburg, SD, finalizes his cover crop decisions by determining how much moisture is already available in the soil. “There’s a lot of people say, ‘Plant them in dry dirt and it’ll happen.’ I won’t do that because you want your covers to be a success,” Forgey said. “We’re really cautious with our covers on these drier years. I go out with a soil probe. I use the soil probes because then you can actually tell what you have for moisture.”
Cronin Farms has a diverse crop rotation, and they normally plant cover crops with higher carbon/nitrogen ratios for grazing after winter wheat harvest.
“When we planted our cover last year, it was after harvest. It was probably like the 6th or 7th of August that we planted it, and at that time with the soil probe, we had 16 inches of moisture in our profile,” Forgey said.
Forgey thought that was a little dry. He said the farm had received just enough rain that spring and summer to make a good crop, but it wasn’t enough to fully recharge the soil profile. Still, after some careful thought, the Cronin Farms team decided to plant the cover crops anyway.
“So, we thought, well, if we caught two or three inches of rain in the fall, that would make up for it,” Forgey said. “That’s what we normally do.”
At the time of cover crop planting, he said the available moisture was at 86 percent of normal, so he reduced his seeding rate by a corresponding percentage. The goal is to reduce the number of plants taking up water in the field.
Source: sdsoilhealthcoalition.org
Photo Credit: minnesota-corn-growers-association
Categories: South Dakota, Crops