Cole noticed that mixed-crop (polyculture) systems often perform better than single-crop (monoculture) systems on his farm. To test this observation, he designed a demonstration trial comparing three treatments with cucumbers: monoculture, simple polyculture and complex polyculture.

Despite challenges with plant loss and drought, Cole observed several patterns:

• The monoculture plots had the highest pest pressure and suffered earlier plant death.
• The simple polyculture produced the highest yield.
• The complex polyculture had the fewest pests but lower yields than the simple polyculture.
• Overall, both polyculture systems supported lower pest pressure and greater beneficial biodiversity than the monoculture.