In an independent study recently conducted in Tennessee, onions that were treated with Dixondale Farms 10-20-10 Fertilizer Compost increased yields up to 40%! You may be able to find a balanced fertilizer, but not one with the essential micronutrients that onions require for optimal bulb formation. Without magnesium, zinc, boron, copper, iron, manganese and molybdenum, plants will have slow growth, tip yellowing and twisting of leaves. The organic humic acids allow the slow release of nutrients into the soil and keep it nice and loose for large bulbs. The 4-lb bag will treat 150 feet of row.