The correct option is D Urea
∙ Organic manure is produced by decaying plant and animal wastes. These decomposed materials provide good nutrient content to the soil making it fertile. Cow dung, fish manure and goat droppings are macro organic manures.
∙ Urea, on the other hand, is a synthetically prepared chemical whose concentration in soil has deleterious effects on plants, animals and on soil fertility as well.