PROCESS EXPO | Expert in Residence
Closing the loop with wastes from fruit and vegetable processing
Chris Simmons | UC Davis, Food Science & Technology
The notion of “closing the loop” refers to production of products using waste streams that are generated during that product’s life cycle. Biomass residues from food processing present many opportunities for this type of recycling. Novel agricultural technologies are creating new ways to return residual organic matter from fruit and vegetable processing, often thought of as waste, back to the soil to benefit crop growth.
While it’s well known that incorporating organic matter into soil improves its fertility, these new technologies are adding even more agricultural value to these processing residues. For example, many fruit and vegetable residues can eliminate pests when amended to the soil under particular conditions. Studies have shown that waste biomass from cabbage1, cauliflower1, olives2, tomatoes3, and onions4, among others, can be used to control a variety of soil pests, such as undesirable fungi, nematodes, and weeds. For some of these materials, the plant residues contain chemicals that either directly inhibit pests or break down into inhibitory compounds, referred to as “biofumigants.” Alternately, the fruit and vegetable residues may simply act as food for beneficial microorganisms in the soil, allowing them to produce pest-inactivating compounds.
Additionally, a variety of irrigation and tarping strategies have been developed to enhance the effects of residue amendment. As conventional pest control methods, such as soil fumigation, face increased regulation and ignite debate over environmental health and safety, there are incentives to adopt new pest management strategies in agriculture. By helping to close the loop, fruit and vegetable processors can help meet this need while simultaneously valorizing their waste, decreasing their disposal costs, and improving sustainability in waste management.
1Anita, B. 2012. Crucifer vegetable leaf wastes as biofumigants for the management of root knot nematode (Meloidogyne hapla Chitwood) in celery (Apium graveolens L.). Journal of Biopesticides 5:111-114.
2Coventry, E., R. Noble, A. Mead, and J.M. Whipps. 2002. Control of Allium white rot (Sclerotium cepivorum) with composted onion waste. Soil Biology and Biochemistry 34(7):1037-1045.
3Achmon, Y., D.R. Harrold, J.T. Claypool, J.J. Stapleton, J.S. VanderGheynst, and C.W. Simmons. 2016. Assessment of tomato and wine processing solid wastes as soil amendments for biosolarization. Waste Management 48:156-164.
4Lima, G., D. Vitullo, R. Altieri, A. Esposito, F. Nigro, I. Pentimone, G. Alfano, and G. Ranalli. 2008. Control of Verticillium dahliae by adding olive mill waste to the rhizosphere of nursery grown plants. Proceedings of the 4th European Bioremediation Conference 3-6.