Many farmers repeatedly plow and till their fields, removing plant materlal from the previo season's harvest each time. Some farmers, however, leave much of this plant residue on top of the soil. They plant each new season's seeds through the residue, driling them into the soil. The crop residues protect the soil from wind and rain, allowing sufficient water to percolate to the soil to allow the new crops to grow. What is this practice called? Contour planting Conservation-tillage farming Alley cropping How does adopting the practices in the following table promote stainable food production and processing? For each practice, check all that apply.