Have you heard than giving soybeans suffering from iron deficiency chlorosis a shot of nitrogen will boost yields?
Well, it's true, but there wasn't enough bang for the buck when North Dakota State University researchers put the idea to the test in 2013 and 2014.
"In the experiment we observed four varieties, each with different IDC ratings, growth types, and maturity ranges," explains Ryan Buetow, NDSU Extension cropping systems specialist.
Different fertilizer treatments were applied to each variety. The treatments were:
No additional fertilizer.
25 pounds of N per acre as urea.
50 pounds of N per acre as urea.
75 pounds of N per acre as urea.
Each N treatment was applied post emergence
Applying additional N increase the level of IDC.
There was no yield increase due to fertilizer application in 2013, but in 2014 N treatments yielded significantly more than the control (no additional fertilizer).
Combined across 2013 and 2014, all N treatments yielded significantly higher than the control – 45.2 versus 42.8 bushels per acre.
"Although there was a [statistically] significant increase in yield over the two years, there were no significant differences in financial returns after cost of fertilizer was accounted for," Buetow says.