Soil Health and Organic Farming

Plant breeding and cultivar development conducted for and within the context of organic farming systems can lead to improved organic crop yields, and thereby facilitate adoption of organic practices that protect and build soil health.

Organic farmers recognize healthy, living soil as the foundation of successful farming, and many seek practical means to reduce tillage in order to protect the soil organic matter, soil life, and improved tilth build up through green manures, compost applications, and other organic practices.

Organic farmers recognize healthy, living soils as essential for successful production. Perhaps the greatest soil health challenge relates to weed management, especially in annual crops. Without conventional herbicides, organic producers often use the practices of tillage and cultivation.

Climate change threatens agriculture and food security across the U.S. and around the world. Rising global mean temperatures have already intensified droughts, heat waves, and storms, and altered life cycles and geographical ranges of pests, weeds, and pathogens, making crop and livestock production more difficult. Intense rainstorms aggravate soil erosion and complicate water management, and higher temperatures accelerate oxidation of soil organic matter. Warming climates modify crop development regulated by growing degree-days or “chill hours,” and threaten production of perennial fruit and nut crops that have strict chilling requirements to initiate growth and fruit set. Thus, agricultural producers have a major stake in efforts to curb further climate change, as well as improving the resilience of their farming and ranching systems to the impacts of climate disruption.

The goal of this guidebook is to help organic farmers navigate the wilderness of soil life and soil health management by providing up-to-date, science-based information on:

• The soil food web, its key components, and functions.
• Assessing and monitoring soil life and soil biological condition.
• Managing soil life for long term soil health and productivity in organic systems.
• Biological management of plant diseases.
• Microbial inoculants and biostimulants: whether, when, and how to use them.

This report summarizes research findings on SOM and soil health in organic farming systems, and outlines some practical applications for organic producers. Companion reports explore soil health-enhancing approaches to fertility and nutrient management, tillage, and weed control; cover crops and crop rotation, and the role of plant genetics in soil health and organic production

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.