* * *Almost hand-in-hand with the ridiculously large scale of a farm comes monocropping, the practice of devoting land to single crops and year-to-year production of the same crop species on the same land. Several factors have led to the increased practice of monocrop agriculture, including a growing global population, urbanization, advancing machinery and technologies, dominance of the seed/pesticide/herbicide market by a small handful of multi-national companies and a shifting political/cultural climate that encouraged farmers to farm "from fencerow to fencerow." Before they were told to "get big or get out" in the 1970s, many farms practiced sustainable farming and cultivated diversified crops. This, however, is no longer the norm.
Monocropping ignores ecological principles. It does not operate on natural methods for weed, disease and pest suppression and re-supplying nutrients to the soil, but instead relies on inorganic (mostly, or organic in some cases) herbicides, pesticides and fertilizers. The ancient natural practices of rotating and diversifying crops was essentially eliminated because rotation requires some land to lay fallow and diversification requires "too many" inputs and can't achieve economies-of-scale production.
Monocropping also contributes to the metabolic rift: cycles of wastes and nutrients have become open and unidirectional, rather than closed as in a natural ecosystem. At one time, the majority of farmers raised crops and livestock on the same farm, a practice that provided a diversity of agricultural products and by-products that could be reused and recycled on the farm (reducing off-farm purchases, a whole other topic...). For example, manure could be used as fertilizer, while crops and crop by-products could be fed to animals. Now animals are increasingly grown in concentrated livestock operations which generate their own set of sanitary and ethical problems. Similarly, many farmers have abandoned animals altogether and now grow only one or two crops. Both of these methods take from the ecosystem in order to meet demands and in the meantime they are producing sicker and sicker products.
Diversity is a good thing, when it comes to farming and when it comes to people. Heaps of evidence demonstrate the negative effects of segregation. Building a healthier ecosystem requires moving away from segregated, monocropped practices and coming back to the integrated, diversified farm and community.