The macronutrients Nitrogen, Phosphorus and Potassium get much-deserved attention, but don’t discount fourth major crop nutrient, Sulfur (S).
Sulfur is an essential component of amino acids, which convert into protein for the plant. It’s required for the production of chlorophyll and helps the plant produce energy for itself.
While in the past acid rainfall contributed significant amounts of sulfur to the soil, more recently with reduced atmospheric deposition and increased yields, plants are looking elsewhere for Sulfur support.
Unlike the other secondary nutrients–calcium and magnesium (which plants take up as cations)–Sulfur is absorbed primarily as SO₄²⁻, which is subject to leaching with high amounts of rainfall.
Plants steadily take up sulfur throughout the season and require a carefully planned crop nutrition program that includes adequate S availability. Supplying multiple forms of sulfur, including both sulfate and elemental S, can help ensure sulfur is available when plants need it.
An Essential Nutrient to Plant Health
Sulfur is an essential component of amino acids, which convert into protein for the plant, and is required for the production of chlorophyll and helps the plant produce energy for itself.
Ensure that Sulfur is available all season long, supplying crops both sulfate sulfur and elemental sulfur, which oxidizes throughout the growing season and replenishing the supply of sulfate that has been taken up by the plant or leached by rainfall.
Crop-Specific Sulfur Practices
Symptoms of deficiency can vary across crop species and by nutrient, but similarities exist for how a sulfur deficiency impacts plant tissue color and appearance.
When sulfur is deficient, younger parts of the plant are affected first, often appearing as discolored leaves or stunted in growth. Sulfur deficiencies may also reduce crop yield and quality.
The Sulphur Institute (TSI), a non-profit advocate for sulfur, who provides information about the nutrient, offers crop-specific sulfur nutrient management practices. Read about sulfur benefits and signs of deficiency, and the 4Rs of sulfur management by crop, in TSI’s infographics: