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.
Soil Health School
The 2026 Soil Health School is set for September 15-17 near Twin Brooks and Marvin, SD.
Small Scale Ag
Soil Health School
The 2026 Small Scale Ag Soil Health School is set for Aug. 28 in Huron, SD.
News & Events
Test grain for nitrates before using it as forage
By Stan Wise With the vast majority of South Dakota in a drought and experiencing high temperatures, grain producers are having to make some tough decisions about their crops. Will those grains produce enough yield to make harvesting them a financially viable option,...
Darling Creek Ranch Named 2026 SD Leopold Award Winner
Sand County Foundation Dan and Sharon Anderson’s Darling Creek Ranch has been selected as the 2026 South Dakota Leopold Conservation Award® recipient. The $10,000 award honors ranchers, farmers, and forestland owners who go above and beyond in their management of soil...
Building operational resilience with soil health
By Stan Wise South Dakota Soil Health Coalition PIERRE, SD – Resilience. It’s one of the prizes that keeps conservation-minded land managers striving for improved soil health. Operational resilience in the face of floods, market fluctuations, rising input costs,...