High levels of fertilizer and pesticides, needed when farmers try to produce high yields of the same crop year after year, pollute water supplies  Experts ttherefore urge farmers to diversify their crops and to rotate their plantings yearly
To receive governmental price-support benefits for a crop, farmers must have produced that same crop for the past several years
Farmers can continue to make a profit by rotating diverse crops, thus reducing costs for chemicals, but not by planting the same crop each year.