Increasing soybean yields with Smart Nutrition™ MAP+MST®
A summary of 15 soybean trials conducted from 2018 to 2020 across the US have confirmed what many researchers have observed – soybean response to sulfur application is unpredictable. Many farmers are experiencing increased occurrence of sulfur deficiency in crops like soybean, but the lack of response to application can be due to many soil factors. Soybean grown on high organic matter soils may not respond to supplemental sulfur applications due to increased levels of sulfur available from the mineralization of soil organic matter.
Soybeans are legumes – form symbiotic relationships with rhizobia to form nodules in roots that biologically fix nitrogen – and therefore require limited (if any) amounts of supplemental nitrogen through fertilizer applications early in the growing season. While nitrogen fertilization is not necessarily required for soybean production, there is some evidence that the ratio of nitrogen to sulfur within the plant is critical during grain fill to maximize protein content.
Soybean grown on coarse textured soil in humid environments may benefit from the slow-release of sulfur from oxidation of Micronized Sulfur Technology (MST®), allowing for sulfur availability later in the growing season when soybean plants are in grain fill. With such a strong relationship between these nutrients within the plant, if nitrogen is limited, there might not be a response to sulfur applications.
Soybean production also requires adequate phosphorus to maximize yields, and soybeans remove large amounts of phosphorus in harvested grain. For every bushel of soybean produced, roughly 1.1 pounds of phosphorus are required, and 80 percent of the phosphorus taken up by the plant is removed during grain harvest. Smart Nutrition MAP+MST allows for high rates of phosphorus application at lower volumes compared to other multi-nutrient fertilizer sources.