Richest source of nitrogen is

A. Dried blood

B. Raw bone meal

C. Fish manure

D. Dry activated sludge

Answer: Option A

Solution(By Examveda Team)

The richest source of nitrogen is Dried blood.
A blood meal is a dry, inert powder made from blood, used as a high-nitrogen organic fertilizer and a high-protein animal feed. N = 13.25%, P = 1.0%, K = 0.6%.
It is one of the highest non-synthetic sources of nitrogen. It usually comes from cattle or hogs as a slaughterhouse by-product.