The correct answer is All are correct. The term bulky organic manure generally includes those materials of natural origin, organic in composition having greater volume per unit content of nutrients. These are used to increase the nutrient status of the soils as well as organic matter content of soils. They are obtained mainly as natural products. Examples: farmyard manure, compost, sewage sludge and green manure. Of these, FYM, compost and green manure are the most important and widely used bulky organic manures.