The study team, lead by University of Wisconsin’s Matthew Ruark, confirmed that radish cover crops can have substantial nitrogen uptake in the fall. The team planted the radish cover crop in the fall for this study.
“It remains unclear if the N in the radish biomass can supply N to a subsequent corn (Zea mays L.) crop,” the team wrote in its abstract for the study.
The study had three main objectives:
- Measure both radish growth and nitrogren uptake.
- Determine what effect radish growth had on the folllowing season’s available nitrogen soil content.
- See if the radish cover crop had an effect on the following season’s corn yields and response to nitrogen fertilizer.
The study was conducted across several sites across Wisconsin.
Results of the Study
As expected, the radish cover crop’s nitrogen uptake ranged from 17.6 to 180.2 pounds/acre-1. But in-season, plant-available nitrogen content differed across the growing seasons. And the cover crop mostly had no or a neutral effect on corn yields, although there were some increases and decreases.
“This research supports the use of radish as a trap crop for fall nitrogen,” the study team writes in its abstract.
But do not expect the cover crop’s biomass to fertilize future crops.