What Nutrients Are In Composted Cow Manure?

What Nutrients Are In Composted Cow Manure? Cattle manure is a valuable source of key nutrients including nitrogen (N), phosphorus (P), potassium (K) sulphur (S) magnesium (Mg), and calcium (Ca) as well as certain micronutrients. Adding manure to soil impacts the chemical, biological and physical aspects of soil quality. What is composted manure good for?