Building Healthy Living Soils for Succesful Organic Farming in the SOUTHERN REGION By Mark Schonbeck and Lauren Snyder With contributions from John Bell, Bryan Hager, Krista Jacobsen, Emily Oakley, Danielle Treadwell, Steve Diver, and Elizabeth Little Building Healthy Living Soils for Succesful Organic Farming in the SOUTHERN REGION FUNDED THROUGH WITH SUPPORT FROM Ceres Trust UNFI Foundation Cliff Bar Family Foundation © 2021 Organic Farming Research Foundation • Santa Cruz, CA Table of Contents Introduction ........................................................................................................................................................... 1 Chapter I: Soil Health Challenges and Opportunities in the Southern Region ...................... 3 Concept 1: Balancing Percent SOM and Microbial Activity in Warm Climates................. 5 Concept 2: How a Changing Climate Affects Soil Health in the South ................................ 7 Chapter II: Organic Soil Health Management Strategies for the Southern Region ............10 Farm Story 1: Applying the Six Principles of Soil Health Management ...............................12 Windy Acres Farm, Orlinda, Tennessee Strategy A: Get to Know your Soil..........................................................................................................15 Strategy B: Manage Nutrients for Soil Health, Crop Production, and Net Returns .............17 Concept 3: Nutrient Budgeting in Organic Systems ..................................................................19 Strategy C: Build Soil Health with Cover Crops .............................................................................24 Concept 4: Cover Crops for Tropical and Subtropical Regions ...........................................26 Concept 5: Cover Crop Genetics: Cultivar can Make a Difference ...................................29 Strategy D: Build Soil Health with Crop Diversity and Crop-livestock Integration ............. 30 Farm Story 2: Diversified Crop Rotation with Livestock-crop Integration ........................31 Elmwood Stock Farm, Georgetown, Kentucky Strategy E: Use Compost, Manure, and Organic Amendments as Supplements .................33 Concept 6: A Simple Test for Compost Maturity and Quality..............................................34 Concept 7: Biochar ...............................................................................................................................36 Strategy F: Enhance the Soil Microbiome ...........................................................................................37 Strategy G: Till with Care ........................................................................................................................40 Farm Story 3: Gearing-down the Tiller to Improve Sandy Soils .............................................41 Mattawoman Creek Farm, Eastville, Virginia Strategy H: Use Soil-saving Weed Management Strategies .........................................................45 Farm Story 4: Landscape Fabric for Weed Control and Cover Crop Termination ...... 48 Crager Hager Farm, Bremen, Georgia Farm Story 5: Repurposing Old High Tunnel Plastic for Soil Solarization, Weed Control, and Cover Crop Termination.......................................................................................... 50 Abingdon Organics, Abingdon, Virginia Strategy I: Make the Crops Fit the Land: Perennial Plantings for Soil Health .......................52 Farm Story 6: Berm and Swale Terraces with Multifunctional Perennial Plantings .......53 Radical Roots Farm, Keezletown,Virginia Special Topic: Managing Soil Health in the High Tunnel ...............................................................55 Farm Story 7: Haygrove High Tunnel Rotation ...........................................................................58 Elmwood Stock Farm, Georgetown, Kentucky Special Topic: Managing Soil Health in Organic Rice Production .............................................60 Concept 8: System of Rice Intensification ....................................................................................62 Chapter III: Resources ....................................................................................................................................64 Knowing your Soil ........................................................................................................................................64 General Resources on Soil Health Management and Cover Crops ..........................................64 Cover Crops and Other Soil Health Practices for the Southern Region .................................66 Perennial Cropping Systems, Permaculture, and Agroforestry ...................................................68 Soil Health in the High Tunnel.................................................................................................................68 Keeping Up with Soil Health Research Developments: Searchable Databases ....................69 Chapter IV: A Deeper Dive into Soil Types and Inherent Soil Properties in the South .....70 Researcher Perspective 1: Farming Florida Soils Sustainably ................................................73 Dr. Danielle Treadwell, University of Florida Chapter V: Soil Health and Organic Farming in the South: Recent and Ongoing Research ............................................................................................................................................. 74 Nutrient Management and Organic Amendments .......................................................................... 74 Cover Crops for the Southern Region .................................................................................................77 Integrated Soil Health Strategies and Crop Diversity .....................................................................81 Soil Microbiome, Inoculants, and Organic Disease Management ..............................................82 Researcher Perspective 2: Organic Rice Research in Southeast Texas .............................85 Steve Diver, University of Kentucky Researcher Perspective 3: Grappling with Root Knot Nematode ..................................... 88 Dr. Elizabeth Little, University of Georgia Cover Crop Based Organic No-till and Reduced Tillage Systems ............................................90 Soil-friendly Organic Weed Management ..........................................................................................92 Soil Health in Perennial Systems ............................................................................................................93 Literature References ....................................................................................................................................95 INTRODUCTION Healthy, living soils provide the foundation for successful and profitable organic farming and ranching. Nowhere is soil health more vital than in the South, where organic producers face intense pressure from weeds, insect pests, parasitic nematodes, and plant-pathogens; extremes of summer heat, drought, and flood; and soil types with inherent fertility limitations. In addition, long growing seasons can make it harder to rebuild soil organic matter, especially during intensive crop production. In a 2015 nationwide survey of organic producers, 79% of respondents from the South cited soil health as a high research priority, a little higher than the national average of 74% (Jerkins and Ory, 2016). Other priori- ties identified by farmers in the South included weed management (70%), fertility and nutrient manage- ment (67%), insect management (62%), disease management (62%), soil conservation (55%), cover crops (45%), and coping with climate change (42%). Many respondents understood the central role of healthy soil in dealing with pests and weather extremes and expressed a need for practical information on how to build soil health in hot climates that burn up soil organic matter (SOM) and promote aggressive weed growth. These challenges have hindered the growth of organic agriculture in the Southern region, which accounted for less than 11% of USDA certified organic operations, and about 9% of U.S. organic sales in 2017 (USDA, 2019). The goal of this guidebook is to help the region’s current and aspiring organic producers develop ef- fective, site-specific soil health management strategies that support successful, resilient enterprises. We begin this guidebook by reviewing the unique challenges and opportunities that organic producers face in building healthy soils in the Southern region (Chapter I). In Chapter II, we explore how to apply organic soil health principles to the region’s soils through a series of practical steps and strategies, illustrated by innovative farmer stories and brief descriptions of underlying scientific concepts (Figure 1). The latter por- tions of the guidebook provide a list of resources for additional reading (Chapter III), a description of the inherent properties of soil types commonly found in the South (Chapter IV), and a summary of the latest soil health research being conducted in this region (Chapter V). BUILDING HEALTHY LIVING SOILS - SOUTHERN REGION 1 Strategy H Strategy A Manage Weeds Strategy G Know pp 45-51, 92-93 Till with Care Your Soil pp 40-44, 90-92 pp 15-16, Strategy C Cover Crops 70-73 Strategy B Minimize Keep pp 24-29, Manage 77-81 Nutrients Soil Soil pp 17-23, 74-77 Disturbance Covered Special Topics: Soil Health in High Tunnels Healthy Maintain Strategy E Law of pp 55-59, 88-89 Organic