Heinemann’s group found that between 1985 and 2010, Western Europe has experienced yield gains at a faster rate than North America for all three crops measured....
Farmers in Mexico, the birthplace of corn, plant a fantastic variety of corn. The plants differ in color, height, ear size, drought tolerance, maturity time, and more. If bad weather shows up late in the season, the early maturing varieties still provided a harvest. If it’s dry, the drought tolerant varieties survive. If a new disease shows up, some of the corn is bound to have some resistance to it whereas other varieties will be more susceptible to it. Biodiversity acts almost like an insurance system.
Planting genetically identical crops results in the opposite. It’s like betting all of your money on one lottery number. And when U.S. corn farmers lose the lottery, they all lose together so the national yield plummets.