Elemental sulfur is a more desirable sulfur fertilizer material compared to gypsum due to the following reasons:
- Increased sulfur availability: Elemental sulfur is a source of pure sulfur, while gypsum contains calcium sulfate. Elemental sulfur can be oxidized by soil bacteria to form sulfate, which is the preferred form of sulfur for plant uptake. Gypsum requires the oxidation of elemental sulfur to sulfate, which can be a slow process.
- Enhanced sulfur mobility: Elemental sulfur can be easily incorporated into the soil and moves more freely within it. On the other hand, gypsum has limited mobility in the soil, making it less effective for delivering sulfur to plant roots.
- Lower calcium content: Gypsum contains a significant amount of calcium, which may not be required in excess in certain soils. Elemental sulfur does not add unnecessary calcium to the soil, making it a more suitable choice when sulfur is the primary nutrient needed.
- Acidification potential: Elemental sulfur has the potential to lower soil pH, which can be beneficial for certain crops that prefer acidic conditions. Gypsum, being a neutral compound, does not contribute to soil acidification.
- Flexibility in application timing: Elemental sulfur can be applied at any time during the growing season, allowing for more flexibility in nutrient management. Gypsum, on the other hand, is often applied in advance to allow time for its slow conversion to sulfate.
In summary, elemental sulfur is considered more desirable as an S fertilizer material due to its increased availability, mobility, lower calcium content, potential soil acidification, and flexible application timing compared to gypsum.