A 33-0-0 fertilizer, often ammonium nitrate or a blend like Urea Ammonium Sulfate (UAS), is used to provide a high, fast-acting source of nitrogen (N) for vigorous vegetative growth, promoting lush green lawns, leafy vegetables, and hay/pasture, supplying both readily available nitrate and ammonium forms for quick uptake by plants, and improving soil fertility. While effective for general plant growth and quick green-up, its sale and use have become restricted due to safety concerns, with substitutes often containing urea and ammonium sulfate.