How are organic manures differing from fertilizers?
Organic manures have low nutrient content and therefore need to be applied in larger quantities. For example, to get 25 kg of NPK, one will need 600 to 2000 kg of organic manure where as the same amount of NPK can be given by 50 kg of an NPK complex fertilizer. The nutrient content of organic manures is highly variable from place to place, lot to lot, and method of preparation. The composition of fertilizers is almost constant. For example, urea contain 46% N regardless of which factory makes it any where in the world.
