A monocrop is one plant growing in the same place, year after year. There are two major problems with monocrops. The first is that they are not conducive to good soil health. Growing only one plant tends to deplete the soil’s nutrients over time, and leaving fields bare for the winter can hasten erosion. Monocrops also provide a friendly home for pests that happen to like that crop, since it shows up reliably each year. The second is that, by only having one crop, farmers are vulnerable to a devastating loss (think Irish potato famine). ⠀
Permaculture (more than one crop) on the other hand promotes biodiversity. It seeks to maximize the number of productive species of plant within a plot, not only to offer a diverse and vibrant number of crops to harvest, but also so that the ecosystem is itself is strong, with different plants performing different functions so that all can thrive. Permaculture design seeks to avoid any one thing – be it a species of insect, a plant or an extreme weather event – becoming too influential on a site, to the detriment of the other parts of the ecosystem.
Source: Washington Post & Regenerative