As commercial corn yields continue to climb, optimizing input efficiency is no longer just about deciding how much nitrogen (N) to apply. Today, there is a lot of information out there that focuses on nutrient interactions – specifically the biological partnership between N and sulfur (S). But a common question persists among agronomists and progressive growers alike: If you crank up your nitrogen application rates, do you need to scale up your sulfur rates in tandem?
Extension nutrient management specialist Dan Kaiser addressed exactly this question over ten study locations in Minnesota. From 2011 to 2013, Kaiser led a rigorous research project conducted across central and southern Minnesota. By examining leaf chemistry at silking (R1) and nutrient concentration in the harvested grain, the study provides definitive insights into managing this complex nutritional duo.
The nitrogen-sulfur partnership: What happens in the plant?
Biochemically, N and S influence separate functions in the plant but they can influence each other. Both are vital building blocks for plant proteins, and a deficiency in one may influence the uptake of the other. Nitrogen tends to have a greater impact on sulfur simply due to the fact that corn tends to be more responsive to nitrogen. The field data confirms this, where applying fertilizer N linearly increased the concentration of both N and S within the corn leaf tissue at silking. However, adding sulfate-S (SO4-S) increased leaf S concentration and had no impact on nitrogen. Nitrogen has a similar effect on S concentration in the harvested grain.
Source : umn.edu