By: Glen Howell
In Midwestern agriculture, there are primarily 4 fertilizers that are actively used for meeting sulfur nutritional needs. They are listed from highest to lowest sulfur concentration. Also listed is their overall analysis & type of product composition:
Elemental Sulfur-90%S; (0-0-0-90S); dry product; sulfur is not in plant available form
Ammonium Thiosulfate (ATS)-26% S; (12-0-0-26S); liquid product
Ammonium Sulfate (AMS)-24% S; (21-0-0-24S); dry product
Potassium Magnesium Sulfate (langbeinite)-21% S; (0-0-21-21S-11Mg); dry product
Calcium Sulfate (SuperCal SO4; CaSO4; gypsum)-17%S; (0-0-0-17S-21Ca); dry product
Potassium Sulfate (SOP)-17% S; (0-0-50-17S); dry product
Crop need for sulfur
Crops need varying amounts of sulfur to complete their life cycle. Much of what is needed for growth is recycled to the soil with plant residues, but there is a net loss with the crop removed. Organic matter (O.M.) in soil is a great sulfur source—each 1% contains 140# of sulfur—but it may not always be available when the crop needs it.
Crop Unit of Measure # Sulfur/Unit of Measure Yield-# Sulfur Removed (Crop removal)
Corn (grain) Bushel 0.08# 200 Bushels-16# S
Corn (silage) Ton 1.1# 30 Ton-33# S
Soybean (grain) Bushel 0.18# 60 Bushels-10.8# S
Alfalfa/Forages Ton 5.4#** 5 Ton-27# S
**Conversations with Extension personnel indicate that 5.4#/Ton crop removal may be too conservative. 6#/Ton was suggested as more appropriate.
For more specific information on sulfur fertilization, product rates & cost comparison, check out our Sulfur Calculator.
Glen Howell is a contributing writer to Yield Starts Here, a blog for farmers, focusing on increasing yield and profitability by focusing on the soil. His other interests include severe weather & old farm tractors. Find additional articles by Glen and other writers at http://blog.calciumproducts.com