Western Oregon has a large quantity of grain straw and the residues from various seed crops and other similar materials of potential value for mulching. Only a small portion of these materials is used for bedding in stables or applied directly to the soil. The burning of stubble and of straw stacks is a common practice. A study to define more accurately the value of such waste products, especially when used as a mulch, should be conducive to their conservation and more effective utilization, particularly since orcharding and small-fruit production in western Oregon lend themselves to mulching practices.These are the considerations that prompted this study to determine the effect of mulching upon the conservation of moisture, the nutrient supply for crop production, and the structure of the soil.