DEFINING REGENERATIVE FARM SYSTEMS & THE EFFECTS OF REGENERATIVE ALMOND PRODUCTION SYSTEMS ON SOIL HEALTH, BIODIVERSITY, ALMOND NUTRITION, AND PROFIT A University Thesis Presented to the Faculty of California State University, East Bay In Partial Fulfillment of the Requirements for the Degree Master of Science in Biological Science By Thomas Lewis Dudash Fenster May 2021 Copyright © 2021 by Thomas Lewis Dudash Fenster ii Abstract Regenerative agriculture aims to improve soil health and promote biodiversity while producing nutritious food profitably. We developed practice-based scoring systems that define regenerative cropland and rangeland, and validate these scoring systems based on whether these scores scaled with regenerative goals on actual farm operations. Natural clusters in the number of regenerative practices used can be used to distinguish regenerative and conventional operations. Almonds are the dominant crop in California agriculture in terms of acreage and revenue generated, and are mostly farmed using practices that degrade the soil, deplete water resources, and reduce biodiversity in the orchard. We examined the soil health, biodiversity, yield, and profit of regenerative and conventional almond production systems that represented farmer-derived best management practices. Regenerative practices included abandoning some or all synthetic agrichemicals, planting perennial ground covers, integrating livestock, maintaining non- crop habitat, and using composts and compost teas. Total soil carbon, soil organic matter, total soil nitrogen, total soil phosphorous, calcium, sulfur, and soil health test scores were all significantly greater in regenerative soils. Water infiltrated regenerative soils six-fold faster than conventional soils. Total microbial biomass, total bacterial biomass, Gram + bacteria, and Actinobacteria were significantly greater in regenerative soils. There was more plant biomass, species diversity, and percent cover in regenerative orchards. Invertebrate richness and diversity, and earthworm abundance and biomass were significantly greater in regenerative orchards. Pest populations, yields, and nutrient density of the almonds were similar in the two systems. Profit was twice as high in the regenerative orchards relative to their conventional counterparts. No one practice was responsible for the success of regenerative farms; their success was the result of simultaneously combining multiple regenerative practices into a single, functional farm system. This style of farming may assist in combatting planetary scale problems (e.g., climate change, biodiversity loss, agricultural pollution, chronic human health problems, declining rural communities, etc.) while making farms more profitable and resilient. Key words: Biodiversity, Economics, Regenerative farming system, Invertebrates, Soil health, Soil microbiology DEFINING REGENERATIVE FARM SYSTEMS & THE EFFECTS OF REGENERATIVE ALMOND PRODUCTION SYSTEMS ON SOIL HEALTH, BIODIVERSITY, ALMOND NUTRITION, AND PROFIT By Thomas Lewis Dudash Fenster Approved: Date: Electronic Signatures Available May 14, 2021 Jonathan Lundgren Jonathan Lundgren (May 7, 2021 14:13 CDT) May 7, 2021 Dr. Jonathan Lundgren Patty Oikawa (May 7, 2021 13:20 PDT) May 7, 2021 Dr. Patty Oikawa May 10, 2021 Dr. Erica Wildy Brian A. Perry (May 10, 2021 10:31 PDT) May 10, 2021 Dr. Brian Perry Acknowledgements Thank you to Dr. Jonathan Lundgren for working with me to conceive and design this study. Thank you to Dr. Jonathan Lundgren and Dr. Patty Oikawa for their help in developing the methodology, analyzing the results, and preparing the manuscript. Thank you to Dr. Erica Wildy for providing logistical support, reviewing the thesis project proposal, and the thesis itself. Thank you to my committee member, Dr. Brian Perry for reviewing the thesis proposal and the thesis itself. Thank you to Chris Bradley, Charles Fenster, Ian Lundgren, Ali Mohammedsabri, and Hilary Vanderheiden for helping collect field samples and conducting lab work. Thank you to Dr. Kelton Welch and Mark F. Longfellow who helped to identify the invertebrates for the analyses. We thank the dozens of other technicians who helped us to collect and enter the data from these projects. Thank you to Natalie Lobue for all her love and support over the course of the project. Funding This work was supported by Ecdysis Foundation, Patagonia Foundation, and W-SARE graduate student fellowship GW19-193, USDA-Pest Management Alternatives Program Grant 2013-34381-21245, NCR SARE Grants GNC16-227, GNC15-207, LNC18-410, and the Globetrotter Foundation. vi Table of Contents Abstract .............................................................................................................................. iii Acknowledgments.............................................................................................................. vi List of Figures .................................................................................................................... ix List of Tables ..................................................................................................................... xi Chapter 1 Thesis Introduction ..............................................................................................1 Chapter 2 Defining and validating regenerative farm systems using a composite of ranked agricultural practices ...............................................................................................6 Introduction ......................................................................................................................6 Methods ............................................................................................................................9 Results ............................................................................................................................21 Discussion ......................................................................................................................26 Tables .............................................................................................................................34 Figures ............................................................................................................................38 Chapter 3 The effects of regenerative almond production systems on soil health, biodiversity, almond nutrition, and profit .........................................................................46 Introduction ....................................................................................................................46 Methods ..........................................................................................................................50 Results ............................................................................................................................64 Discussion ......................................................................................................................73 Tables .............................................................................................................................85 Figures ............................................................................................................................94 vii Chapter 4 Thesis Conclusion ...........................................................................................102 References ........................................................................................................................106 Appendix ..........................................................................................................................127 List of Figures Figure 2.1. The relationships of regenerative farming intensity on fine particulate organic matter in cornfields of the Upper Midwest (A) and percent soil organic matter in California almond orchards (B) .....................................38 Figure 2.2. Total soil carbon as it relates to the number of regenerative practices in California almond production systems .....................................................39 Figure 2.3. Water infiltration rates in the soils of California almond orchards in relation to the number of regenerative practices on each orchard .............40 Figure 2.4. Haney test scores on soils from California almond orchards with increasing numbers of regenerative practices. ...........................................41 Figure 2.5. Plant species richness on the orchard floor in California almonds (A), and plant diversity (Shannon H; B) and biomass index (C) in rangelands of the Northern Plains as they relate to how regenerative a farm is ..........42 Figure 2.6. The invertebrate species diversity (Shannon H) on the soil surface in cornfields of the Upper Midwest (A), and on the orchard floors of California almonds (B), as they relate to the number of regenerative practices implemented on farms ................................................................43 Figure 2.7. Invertebrate species diversity (Shannon H) in dung pats (A) and the abundance of dung beetles (B) as they relate to regenerative intensity on ranches in the Northern Plains ..............................................................44 Figure 2.8. Net profit of California almonds as it relates to the number of regenerative practices on orchards. ............................................................45 ix Figure 3.1. Haney soil health scores in regenerative and conventional almond orchards ......................................................................................................94