Yigal Achmon1,2, Jesús D Fernández-Bayo1,2, Katie Hernandez3,4, Dlinka G McCurry3, Duff R Harrold2, Joey Su1, Ruth M Dahlquist-Willard3, James J Stapleton5, Jean S VanderGheynst2, Christopher W Simmons1. 1. Department of Food Science and Technology, University of California, Davis, CA, USA. 2. Department of Biological and Agricultural Engineering, University of California, Davis, CA, USA. 3. University of California Cooperative Extension, Fresno County, Fresno, CA, USA. 4. School of Natural Sciences, Fresno Pacific University, Fresno, CA, USA. 5. Statewide Integrated Pest Management Program, University of California, Kearney Agricultural Research and Extension Center, Parlier, CA, USA.
Abstract
BACKGROUND: Biosolarization is a fumigation alternative that combines passive solar heating with amendment-driven soil microbial activity to temporarily create antagonistic soil conditions, such as elevated temperature and acidity, that can inactivate weed seeds and other pest propagules. The aim of this study was to use a mesocosm-based field trial to assess soil heating, pH, volatile fatty acid accumulation and weed seed inactivation during biosolarization. RESULTS: Biosolarization for 8 days using 2% mature green waste compost and 2 or 5% tomato processing residues in the soil resulted in accumulation of volatile fatty acids in the soil, particularly acetic acid, and >95% inactivation of Brassica nigra and Solanum nigrum seeds. Inactivation kinetics data showed that near complete weed seed inactivation in soil was achieved within the first 5 days of biosolarization. This was significantly greater than the inactivation achieved in control soils that were solar heated without amendment or were amended but not solar heated. CONCLUSION: The composition and concentration of organic matter amendments in soil significantly affected volatile fatty acid accumulation at various soil depths during biosolarization. Combining solar heating with organic matter amendment resulted in accelerated weed seed inactivation compared with either approach alone.
BACKGROUND: Biosolarization is a fumigation alternative that combines passive solar heating with amendment-driven soil microbial activity to temporarily create antagonistic soil conditions, such as elevated temperature and acidity, that can inactivate weed seeds and other pest propagules. The aim of this study was to use a mesocosm-based field trial to assess soil heating, pH, volatile fatty acid accumulation and weed seed inactivation during biosolarization. RESULTS: Biosolarization for 8 days using 2% mature green waste compost and 2 or 5% tomato processing residues in the soil resulted in accumulation of volatile fatty acids in the soil, particularly acetic acid, and >95% inactivation of Brassica nigra and Solanum nigrum seeds. Inactivation kinetics data showed that near complete weed seed inactivation in soil was achieved within the first 5 days of biosolarization. This was significantly greater than the inactivation achieved in control soils that were solar heated without amendment or were amended but not solar heated. CONCLUSION: The composition and concentration of organic matter amendments in soil significantly affected volatile fatty acid accumulation at various soil depths during biosolarization. Combining solar heating with organic matter amendment resulted in accelerated weed seed inactivation compared with either approach alone.
Authors: Jesus D Fernandez-Bayo; Emily A Shea; Amy E Parr; Yigal Achmon; James J Stapleton; Jean S VanderGheynst; Amanda K Hodson; Christopher W Simmons Journal: Waste Manag Date: 2019-10-08 Impact factor: 7.145