The experience of cotton farmers and the boll weavel in 19th century plantations proved the potentially fatal weakness of monocultural agriculture. One opportunistic pest can wipe out entire crops very quickly.
Nature hosts myriad plant species and life forms in the soil, where there is a balance of competition and synergy with the full spectrum of organisms ranging from bacteria to fungi, from mites to earthworms.
According to Dr. Jill Clapperton, biodiversity provided with the use of cover crops adds flexibility, resilience and resistance to soil health. Farmers can virtually tailor the biological life in their soil by understanding how particular crops function.
For instance, canola and other brassicas are a non-host of mycorrhiza, the community of fungi and bacteria that live in the area around plant roots. But flax, sunflowers and corn depend on a healthy mycorrhiza population.
That means growers can manage the growth and decline of the mycorrhiza population through crop rotation to ensure the beneficial organisms are there to work with the crop.
Also, for reasons still being studied, certain brassicas like Tillage Radish® stimulate earthworms and insects in the soil. Having those crops in a rotation can build the soil’s population of beneficial organisms.
Biodiversity also stimulates predators that feed off pest species, which helps make insecticides less necessary.