Chemical Properties

Reactive Carbon

Slaking is the breakdown of large, air-dry soil aggregates (>2-5 mm) into smaller sized microaggregates (<0.25 mm) when they are suddenly immersed in water. Slaking occurs when aggregates are not strong enough to withstand internal stresses caused by rapid water uptake. Internal stresses result from differential swelling of clay particles, trapped and escaping air in soil pores, rapid release of heat during wetting, and the mechanical action of moving water.

Soil Electrical Conductivity

Soil electrical conductivity (EC) measures the ability of soil water to carry electrical current. Electrical conductivity is an electrolytic process that takes place principally through water-filled pores. Cations (Ca2+, Mg2+, K+, Na+, and NH4 +) and anions (SO4 2-, Cl-, NO3 -, and HCO3 -) from salts dissolved in soil water carry electrical charges and conduct the electrical current.

Soil Nitrate

Nitrate (NO3 -) is a form of inorganic nitrogen (N) naturally occurring in soils. Sources of soil NO3 – include decomposing plant residues and animal manure/compost, chemical fertilizers, exudates from living plants, rainfall, and lightning.

Soil pH

Soil pH generally refers to the degree of soil acidity or alkalinity. Chemically, it is defined as the log10 hydrogen ions (H+) in the soil solution. The pH scale ranges from 0 to 14; a pH of 7 is considered neutral. If pH values are greater than 7, the solution is considered basic or alkaline; if they are below 7, the solution is acidic.

Registration Open for 2026 Soil Health Schools!

The Coalition will host two Soil Health Schools in 2026! The West River Soil Health School is set for June 24-25 near Caputa, SD, and the South Dakota Soil Health School is set for Sept. 15-17 near Twin Brooks and Marvin, SD. These events are designed for agricultural producers as well as anyone with an interest in learning how to manage soils for resiliency and profit. The agenda features classroom style presentations by producers and technical experts from across the state and region, as well as hands-on experiences in the field. Area producers will share their challenges and successes with various methods for improving soil health, to an average class size of 30-40. Registration is open, so check out our events page to learn more!