Nitrogen.
Potassium is the element that used to be first to make fertilizer.
Nitrogen.
Nitrogen.
The first element in the fourth period, which is used in making fertilizer, is potassium.
potassium
This chemical element is potassium (K).
Nitrogen is.
A good fertilizer for agriculture is usually high in nitrogen.
Nitrogen.
Phosphate fertilizer is a compound, not an element. The compound contains phosphorus.
nitrogen
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