- Author: Janet Byron Managing crop residues to essentially make
them disappear has been the norm in California agriculture. But
a growing body of research, and experience with conservation
tillage on thousands of acres of Central Valley farmland, is
showing that reducing tillage and leaving crop residues on the
soil surface can improve water use efficiency. “Crop residues
are an inevitable feature of agriculture,” Jeffrey Mitchell,
cropping systems specialist in the Department of Plant Sciences,
UC Davis, wrote in the April-June 2012 issue of California
Agriculture journal. “Because no harvest removes all material
from the field, the remaining plant matter accumulates and is
typically returned to the soil through a series of mixing and
incorporating operations involving considerable tractor
horsepower, an array of tillage implements and cost.”
Conservation tillage is a suite of low-impact cultivation
practices that includes leaving crop residues on the soil
surface and planting new crops on top, significantl