Why is complexity in the farm fields important for agriculture? "We talk about diversity being important in our human communities, and it's the same thing in agricultural systems," says David Chaney, an annual cropping systems analyst for the UC Davis-based UC Sustainable Agriculture Research and Education Program. The program recently organized a training program on biodiversity. Varied crop rotations, the appropriate use of cover crops, and the establishment of diverse native plants and animals on the farm edges is vital to the quality of soil, the activity of pests and the stability of farm income, according to Chaney.