Each year, sulfur is the fourth-most required macronutrient. Though it’s often considered secondary, it’s critical to a season-long balanced crop nutrition plan.
Over the last 15 years, median soil test sulfur levels observed by the Penn State Agricultural Analytical Services Laboratory have fallen by 50% and reports of observed sulfur deficiency in field and forage crops have increased.
This is due largely in part to the reduction of atmospheric depositions of sulfur, which have decreased significantly since amendments to the Clean Air Act were passed in 1995.
Sulfur deficiencies can often look like nitrogen deficiencies. Nitrogen deficiency affects older leaves on corn and soybeans, while sulfur deficiency is characterized by newer leaves turning yellow or pale green. This may seem like a cosmetic problem, but it’s symptomatic of greater issues. Sulfur is responsible for helping multiple growth functions like:
- Nitrogen fixation
- Chlorophyll formation
- Enzyme activity
- Protein and oil synthesis
Sulfur uptake occurs over the entire growing season and is relatively constant from planting to maturity. Unlike nitrogen, in which 70%-75% is taken up by the flowering stage, only 40%-50% of total sulfur is taken up by this time.
Charts courtesy of University of Illinois Urbana-Champaign (UIUC) Department of Crop Sciences.
Many commodity fertilizer blends only offer sulfate sulfur, which is only available immediately for early-season growth. This leaves plants without the complete sulfur profile they need throughout the long growing season. MicroEssentials® delivers sulfate as well as elemental sulfur, which breaks down over time, so crops get the sulfur they need, all season long.
Dive further into sulfur’s importance in crop growth and development with Scott Foxhoven, Product Testing Specialist for The Mosaic Company.
