Why Zinc Sulphate Should Not Be Mixed with Phosphorus-Containing Fertilizers
In agriculture, combining nutrients can seem like a smart way to save time and improve efficiency. However, not all fertilizers are compatible. One common mistake many farmers make is mixing zinc sulphate with phosphorus-containing fertilizers like DAP, SSP, or MAP. This combination can actually harm your crop instead of helping it.
The Problem: Chemical Reaction
When zinc sulphate is mixed with phosphorus fertilizers, a chemical reaction occurs. Zinc reacts with phosphate ions to form zinc phosphate, which is insoluble in soil. This compound gets locked in the soil and is no longer available to the plant roots.
Result: Nutrient Lock-Up
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Zinc becomes unavailable to the crop.
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Phosphorus efficiency also decreases.
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Leads to zinc deficiency symptoms like stunted growth, yellowing of young leaves, and reduced yield.
Why This Matters
Both zinc and phosphorus are critical nutrients. Zinc helps in enzyme function, hormone production, and root development. Phosphorus supports root growth, flowering, and energy transfer. If either is unavailable, crop health suffers.
Best Practice
Apply zinc and phosphorus separately, either at different times or through different methods (e.g., one through soil, the other via foliar spray).
Maintain gap of at least 10–15 days between applications if applied through soil.
