Target: Soil—physical, chemical, and biological characteristics as indicators of soil health.- Importance to Food & Agr: Soil is the foundation of food production and ecosystems of all sorts. The physical, chemical, and biological characteristics of soils are common indicators of a soil’s overall health. In turn, soil health is critical to the quantity and the quality of the food produced, and to the resilience of ecosystems of all kinds to extreme weather, a changing climate, and other pressures.
- Issues: First, wind and water erosion—often due to industrial agriculture practices—is depleting the amount of agricultural soils in many areas to critical levels. This is essentially irreversible in human time-scales due to the slow rate of new soil being formed.
Besides soil loss, industrial growing practices, including synthetic pesticides and fertilizers, heavy equipment, monocultures, and overwatering often lead to soil compaction, salinization, loss of organic matter and natural fertility generation, increased vulnerability to pests and disease, and loss of many beneficial soil organisms that are key to healthy soils.
Agriculture has caused great losses of soil and soil quality, but regenerative and similar production systems—in gardens, farms, and ranches—focus on soil health to help reverse this trend.
- Observing Options—Monitoring these indicators over time can reveal recovery after damage from ag practices or extreme events, results of improving soil management, and degradation or improvement more broadly:
- Erosion—look for tiny to large gullies forming on slopes due to water running over bare soil. Small deltas of eroded soil at the bottom of slopes and muddy creeks and rivers indicate erosion. Wind erosion is best seen in action or where the soil particles settle in sheets or drifts and dunes.
- Salinization—look for white crusty salt deposits on the soil due to excess water and resulting evaporation at the soil surface.
- Soil quality—one subjective clue to overall soil health and good treatment is healthy diverse vegetation on the land without excessive pests, diseases, or invasives. Healthy soil structure is indicated by good drainage of water into the soil and soil breaking into small clumps when dug up and which don’t just fall apart. Standard soil tests through Extension can reveal organic matter levels and fertility as indicated by chemical nutrients, acidity (pH), and more. Alternative soil tests focus on the more intricate, but more meaningful biological indicators.
- The NRCS (Natural Resources Conservation Service) has a excellent comprehensive website on soil health indicators, resources for educators, and much more on soil health observations.
- Citizen Science: You can report your first sightings of earthworms on iNaturalist as part of their vertical migration in the soil—more of a monitoring of seasons than of soil health, but increases awareness. Monitoring earthworm presence in gardens and fields is one good indicator soil health and worth tracking whether part of a reporting program or not.
There are a number of local citizen science programs across the country that monitor soil health, and you can start your local program—simply Google “soil citizen science.”
- Getting Started Tip: Observing and monitoring earthworms over time is one of the easiest ways to start and suitable to all ages—and a very important indicator. Sending your soil for testing every year or so can be very useful for monitoring how your garden, farm, or ranch soils are doing. Paying attention to soil erosion and salinization across the landscape is easy and very informative.
