Soil health slides
- 1. Soil Health: physics Traditional soil test = soil physics + chemistry Soil = Living System Soil health test = soil physics + chemistry + biology
- 4. Soil Health & Ag Crop yield potential in a field increases ~12% for every 1% increase in OM. Barley yielding 50 bu/acre at a 0.5% OM expect to yield 56 bu/acre at a 1.5% OM. Increasing OM by 1% - adds ~ 22,000 gallons of additional water capacity/acre. Southern Idaho’s low rainfall and reliance on irrigation Tillage, monocropping, and overapplication of fertilizers decrease soil OM overtime. Continuous tillage -> soil loosens to smaller aggregates -> erosion, nutrient/water runoff. Soil OM affects soil properties (structure, moisture retention, biological activity, and plant nutrient availability)
- 5. Idaho Soil Health & Ag In ID, lower OM, higher OM depletion rates, greater soil susceptibility to compaction, and higher soil fragility index are closely associated with agricultural activity. Soil OM OM loss Soil Comp. Soil Fragility
- 6. Soil Health parameters and SHI Evaluates soil health indicators ( soil respiration (Solvita CO2 burst test), water-soluble organic carbon and organic nitrogen and their ratio-> indicate amount of food readily available to soil microbes and plants Other: nitrate, ammonia, phosphate, aluminum, iron, phosphorus, calcium, magnesium, and sodium. Soil Health Score/Index: calculated based on soil respiration and water extractable carbon and nitrogen. SHI can be used to compare: a specific field over time, or between fields. The goal - to improve the soil health score by utilizing soil building practices such as no-till and cover crops.
- 7. SHI - challenges Soil health test - methodology requires standardization. Specifically: carbon dioxide evolution method require optimization for moisture content, temperature and labware to resolve performance issues. Methods require cross-lab validation to resolve intra- laboratory issues, and lab performance testing to assure quality soil analysis data. Extensive field calibration research is required to validate test interpretation. Cost: $50 - $100/sample