Increasing cotton yields with Smart Nutrition™ MAP+MSTĀ®

When it comes to cotton production, soil fertility inputs are the biggest investment for maximizing yields. Farmers mostly focus on nitrogen fertility due to the delicate balance between too little and too much. However, sulfur deficiency is appearing more often and reducing cotton lint yield.

A summary of cotton trials conducted in 2018 shows a 23 percent (roughly 243 pounds per acre) increase in cotton lint yield with the application of sulfur, either as Smart Nutrition MAP+MST or ammonium sulfate (AMS). This is a significant increase in yield with sulfur rates around 15 pounds per acre. Cotton grown following peanut production may not respond to supplemental sulfur applications due to high rates of sulfur applied as gypsum to peanuts. A soil test may give some indication on potential yield response.


Cotton grown on coarse textured soil carries a higher potential for sulfate leaching losses, especially from a source like AMS where all the sulfur present is in the sulfate form. Split applications of AMS are recommended due to the increased risk of leaching. Smart Nutrition MAP+MST offers season long sulfur availability as a slow release fertilizer (seen here in petiole tissue samples) while giving the farmer added protection from sulfate leaching.


Smart Nutrition MAP+MST has the added benefit of containing both nitrogen and phosphorus. Applied as a starter fertilizer, Smart Nutrition MAP+MST can aid in faster initial growth and potentially decrease time to maturity and weed interference. Generally, farmers could see the greatest benefit of starter application in medium to heavy textured soils, soils low in soil test phosphorus, and cool soil temperatures.