BROOKINGS — Do you believe the highest yields return the greatest profit? Are you managing for maximum yields? Do you attempt to manage your corn crop for the highest yields as a result of what yield contest winners say?
SDSU Extension agronomy specialists say if you have answered yes to any of these questions, you might be missing some profit.
“The highest, or maximum yields do not necessarily correspond to the highest net returns,” said Anthony Bly, SDSU Extension soils field specialist. “Accepting yields below the maximum in your area may be in your best interest.”
He, along with colleagues Sara Berg, SDSU Extension agronomy field specialist, and David Karki, SDSU Extension agronomy field specialist, discuss this idea in the following article.
They point to a replicated research project that compared nutrient application rates.
“As our agricultural systems become more tested by economic bottom lines and environmental concerns, the importance of strict management of our nutrient resources cannot be overstated,” Bly said.
This corn study in Minnehaha County compared cost-benefit ratios associated with different nutrient recommendation strategies (Table 1).
“Although the highest yielding treatment was from the maximum nutrient application strategy with 192.9 bushels per acre, the most profitable nutrient management strategy was the N only (nitrogen only) application, which had the lowest yield,” Berg said.
A very close second, separated by only $0.83 net return, was in the field that followed the university recommendations based on unbiased nutrient research calibration and found within the SDSU Extension Fertilizer Recommendation Guide.
Attempting to go after the maximum is not profitable with a loss of $-129.21 compared with university recommendations.
The “what if” treatment uses the yield from the maximum treatment only to compare a “what if” scenario for nutrient rates more in line with what producers are doing in the field, which is $104.30 per acre nutrient cost; this “what if” treatment still lost $-67.82 compared with the university recommendations.
“The secret to profitable nutrient application is knowing how much to apply based on accurate field yield history and soil test knowledge,” Karki said.
He explained that for the best yield-to-profit outcome, nutrient rates should be based on sound university recommendations, which do not include nutrient applications, based on crop nutrient removal.
In this research, soil test P (phosphorus), K (potassium), and Zn (zinc) were in the “very high” (VH) soil test category and therefore required no additional nutrient application.