Peanuts grow best in light, sandy loam soil with a pH of 5.9–7.Therefore, they are valuable in crop rotations. Also, the yield of the peanut crop itself is increased in rotations, through reduced diseases, pests and weeds. Adequate levels of phosphorus, potassium, calcium, magnesium, and micronutrients are also necessary for good yields. To develop well, peanuts need warm weather throughout the growing season. They can be grown with as little as 350 mm of water, but for best yields need at least 500 mm. Depending on growing conditions and the cultivar of peanut, harvest is usually 90 to 130 days after planting for subspecies A. h. fastigiata types, and 120 to 150 days after planting for subspecies A. h. hypogaea types. Subspecies A. h. hypogaea types yield more, and are usually preferred where the growing seasons are long enough.