We hear the most about nitrogen, phosphorous and potassium. We know how important they are for high yielding corn. But something that comes in at a close second is sulfur. It is also the nutrient that has decreased the most in our soils. So, by adding sulfur to your soils, you are doing yourself a favor.
The Sulfur Facts
Ken Ferrie, Farm Journal Field Agronomist, explains that if you have 200 bushel corn, you are taking up 34 lb. of sulfur per acre. He shows this with the equation, corn removes 0.08 lb. of sulfur from grain + 0.09 lb. in the stalk equaling 0.17 lb. total. Sulfur comes in many forms. Elemental sulfur ions, mineral sulfate and sulfide gas. There are two kinds needed for crop growth: sulfate which is available immediately and elemental which oxidizes for late season sulfur uptake.
Sulfur’s Benefit to Plants
One of sulfurs most important jobs is to help produce protein molecules and amino acids. These craft chlorophyll, lignin and pectin. Sulfur also stabilizes nitrogen, fabricates enzymes/vitamins, aids in seed production, promotes nodule formulation in legumes and facilitates translocations in sugars. When a plant is deficient in sulfur, it will not be its normal bright green color and will also result in stunted growth. Because the plants will start to become weak in nutrients, they will produce less growth per heat unit per day. In order to tell the difference between sulfur and nitrogen deficiency, remember to check the newer growth of the plant because that is where the sulfur deficiency will show.
How Much Sulfur do Plants Consume
When sulfur is in the soil, plants consume it through the root system. This all depends on how much the roots make contact with the sulfur as they grow through the soil. Sulfur can move to the roots through mass flow and diffusion. In mass flow, water that contains sulfur will be pulled to the roots and in diffusion, sulfur moves from the more concentrated area to the less concentrated area. Ferrie says that organic sulfur can be created when it is picked up by plants as a building block of protein and amino acids. This organic form is what the plants will use versus the inorganic form it begins as. Some plants will immobilize the sulfur while others will oxidize it into sulfate. Your sulfur program should be designed in order that plants do not fall short of the sulfur they need.
Maintain a Balanced pH
One of the things we recommend is to maintain a balanced pH. Ken Ferrie also recommends this for sulfur programs. If a soil becomes too acidic or alkaline, there will be sulfur issues. Applying more sulfur fertilizer is one of the ways we suggest maintaining this. Our nitrogen source we carry, a product called Ntise, is a superior program to 28% and it can also include a 2% or 3% sulfur source. Ntise is ideal for corn at pre-plant, corn at plant, corn at sidedress, and wheat at topdress. If you are shooting for higher yields then please feel free to contact us about sulfur and we can discuss ways to ensure you are getting enough in your fields.