Monday, November 5, 2007

Monitoring Fates of Food Processing By-products on California Farmlands.

Sajeemas Pasakdee, California State University-Fresno, California Agricultural Technology Institute (CATI), 2910 E. Barstow Ave. M/S OF115, Fresno, CA 93740 and Nat Dellavalle, Dellavalle Laboratory Inc., 1910 W McKinley Ave Ste 110, Fresno, CA 93728.

Food processing facilities, especially those using raw fruit, nut, and vegetable- base materials, generate various types of by-products or non-hazardous wastes. The constituents of these wastes are dependent on the source of raw material and the substances associated with processing. The use of land-applied non-hazardous wastes as an agricultural soil amendment is projected to rise because of public concerns regarding environmental impact and economic constraint of their disposal in landfill or incineration, as well as because of presumed inherent agricultural benefits. This practice is important not only for recycling nutrients but also for minimizing concentration of elements of concern (e.g. sodium, chloride, and trace elements) that would otherwise be concentrated elsewhere. Public concerns regarding the impact of food processing by-products (which contain high moisture content, low pH, high total dissolved solids, and trace elements) are that they may impair soil and water quality upon application to California farmlands. The primary goal of this project was to develop best management practices for sustainable reuse of food processing by-products as a soil amendment. Solids, semi-solid, or slurry forms of food processing by-products are transferred to dry-fallow soils before incorporation. Growers often plant forage crops (e.g., alfalfa, Sudan grass, and silage corn) on sites receiving food processing by-products application prior to planting. We monitored fates of food processing by-product constituents through soil profile, crop removal, and their movements that may influence soil chemical properties and trace element accumulations in plant tissues on various field sites with the history of receiving food processing by-products under the Program established by Dept. of Environmental Resources, Stanislaus County (Modesto, CA). The preliminary results from this study will be discussed.