Organic fertilizer is a type of fertilizer made from natural materials such as plant and animal waste, compost, and other organic matter. Common organic fertilizers include bonemeal (8 letters), GUANO (5 letters), HUMUS (5 letters), and PEAT (4 letters). Bonemeal is made from ground-up animal bones and is rich in phosphorus and calcium. GUANO is a type of bird or bat droppings that is high in nitrogen and phosphorus. HUMUS is a dark, earthy material made from decomposed organic matter. PEAT is a type of soil made from partially decomposed plant material and is high in potassium. All of these organic fertilizers can be used to improve soil fertility and promote healthy plant growth.