Soil Health

Soil in jars

We are exploring how different farming techniques impact soil health, and how soil health in turn affects crop productivity and the environmental impact of farming

Soil Health in Context

  • Soil that is healthy can sustain its ecosystem of plants, animals, and microbes over long time frames
  • Healthy soil provides benefits on the farm, like better water-holding capacity and nutrient cycling, reduced nutrient runoff and soil erosion, and improved crop yields
  • Farmers and researchers are exploring how different farm management systems can be used to improve soil health and help ensure the sustainability of California agriculture

How we look at soil health

For over 20 years we have been exploring how different management practices affect soil health. Practices we are investigating include:

  • Winter cover crops: Legume cover crops take nitrogen from the atmosphere and add it to the soil. Cover crops planted in the wintertime when fields may otherwise lay fallow can also help reduce runoff and the associated losses of sediment, nutrients, and pesticides.

  • Applying compost or other organic wastes: Using wastes such as manure, compost, and biochar as alternatives to fossil-fuel-based mineral fertilizers may improve soil health by enhancing the soil’s water-holding capacity.

Side by side of plants and soil

Key research questions we are exploring at the Ranch include:

  • How do soil amendments—like cover crops, biochar, manure, and biodigestate—affect soil chemistry, soil biology, and crop productivity?
  • How do organic, conventional, and mixed crop management systems affect soil health?
  • How does the long-term use of a soil management practice (over 20+ years) affect soil microbial diversity?
  • How does soil microbial diversity, in turn, affect greenhouse gas production and soil structure?
  • How does the long-term use of a soil management practice (over 20+ years) affect the amount of atmospheric carbon sequestered in the soil?

 

Featured Research Projects

  • Management systems and soil quality
  • Manure and winter cover crops are used by organic farmers as sources of nitrogen and other nutrients. Research at Russell Ranch is exploring how combining these fertilizers with conventional farming methods impacts crop yields, soil chemistry, and soil health.

    Explore organic, conventional, and mixed system impacts on inputs and soil chemistry in the interactive graphic.
  • Soil health assessment
  • This section is still under development. See some Russell Ranch research results below, and stay tuned for updates.
    The use of cover crops increases active carbon, soil organic matter, soil respiration, and aggregate stability, which are all indicators of soil health. Figure adapted from NRCS Soil Health Assessment at Russell Ranch.

    The use of cover crops increases active carbon, soil organic matter, soil respiration, and aggregate stability, which are all indicators of soil health. Figure adapted from NRCS Soil Health Assessment at Russell Ranch.
    Aggregate size fractions in organic furrow- and drip-irrigated systems with poultry manure compost inputs, compared to a conventional drip-irrigated system with synthetic inputs.

    Aggregate size fractions in organic furrow- and drip-irrigated systems with poultry manure compost inputs, compared to a conventional drip-irrigated system with synthetic inputs.