Technological advances in soil preparation and seed placement at planting time, use of crop rotation and fertilizers to improve plant growth, and advances in harvesting methods have all combined to promote wheat as a viable crop. This grain is grown on more land area than any other commercial food. Wheat is grown on more than 216,000,000 hectares (530,000,000 acres), larger than for any other crop. The most common forms of wheat are white and red wheat. Wheat normally needs between 110 and 130 days between sowing and harvest, depending upon climate, seed type, and soil conditions.