Use of paper mill residues in vegetable production holds promise for improving soil quality, particularly in course-textured sandy soils where increases in organic matter content can greatly impact soil chemical, biological, and physical properties. Few studies have evaluated the intermediate to long-term effects of repeated organic matter additions on soil quality and crop health, particularly in irrigated sand-based vegetable production. One of the primary objectives of this project is to determine the influence of fresh paper mill residues (PR) and composted PR on crop disease incidence and severity and ultimately crop yields and quality. Our evaluation of PR amendment effects on crop diseases should help us develop strategies for reductions in pesticide use.

We are working with large volume, locally available organic waste streams; fresh and composted paper mill residues. Both of these organic amendments have been successfully applied to Wisconsin soils for soil improvement and crop yield enhancement (Bowen et al., 1995). Wisconsin vegetable growers in regions of sandy soils are now utilizing a variety of paper mill residues to improve soil physical properties and for crop nutrient supply. Composting of paper mill residues and its effects on potato growth and yield in sandy soils has previously been investigated (Bowen et al., 1995).