Soil Health
Soil health is a growing focus of agricultural operations and other activities that can affect soil. It focuses attention on the diverse ecology and functions inherent in soils. The U. S. Dept. of Agriculture's NRCS is advancing soil health initiatives, as is the Soil Health Institute (which has published literature reviews on the impacts of manure and biosolids applications) and the Soil Health Partnership.
California, the nation's breadbasket, is taking the lead in advancing formal soil health policies. After legislation was passed to address healthy soils, an Action Plan was published in September 2016. The state's Healthy Soils Initiative webpages explain the numerous reasons why investing in soils is so important and impactful, not only for sustaining agriculture and the humans that depend on it far into the future, but to address climate change and other environmental issues.
Steps to soil health include (as noted by CA Dept. of Food & Agriculture):
- reduce soil disturbance
- diversify soil biota
- keeping living roots growing in soils all year
- keep soil covered with plants and mulch
Biosolids and other organic residuals are playing a significant part in California's Healthy Soils Initiative. Why? Because returning organic matter to soils builds soil carbon (C) and stimulates further carbon sequestration while providing macro- and micro-nutrients that support soil ecosystems and crops.
See:
What is Soil Health? - a Cornell Fact Sheet, December 2016
Soil Health Assessment - a USDA NRCS resource
Cornell Soil Health Assessment Training Manual, 2016
Robert Deutsch, AgVise presentation "Soil Health," 2017
Will Brinton: Webinar on Soil Health, March 2018
Why Organic Matter is Important
(from a Synagro presentation "Building Health Soils with Organic Residuals," 2017).
- Decreases soil erosion
- Supplies nutrients
- Buffers against pH change
- Holds water
- Increases the cation-exchange capacity, which protects against leaching loss of nutrients
- Decreases compaction
- Stores nutrients
- Makes soil easier to till
- Helps retain added fertilizer
- Protects against plant diseases
- Better aerated=more permeable
- Protects against heavy metals & salt toxicities
- Detoxifies pesticides
- Contributes to storage of atmospheric CO2
- Promotes high yields
- Promotes microbial breakdown of toxic substances
- Makes it possible to grow acid loving plants
- Supports microorganisms that recycle nutrients
- Promotes healthy soil formation