What does healthy soil look like

Stephanie McLain, with NRCS, showcases two different soil samples during a soil health demonstration:

1) From a field that utilizes conventional practices with tillage and low diversity

2) From a field that employs a carbon farming approach.

It’s apparent from a simple sight test that the soil compositions are quite different. The conventional sample takes on a blocky shape, with few or no obvious pores. The carbon farming sample has a distinct architecture to it, with natural aggregates and continuous pore spaces. 

When each soil sample is placed in water, the results diverge almost immediately, with the conventional soil sample quickly breaking down into sediment, while the carbon farming sample retains most of its natural shape through strong aggregation. Due to tillage and the resulting lack of air channels and biological glues (fungi, bacteria, plant roots, etc.), it’s apparent that the conventional approach leads to the disappearance of aggregates, resulting in a mud-like outcome. This soil then has a high chance of experiencing frequent ponding and poor infiltration, creating a double risk to crops of the saturated soil surface and increased vulnerability to drought due to poor subsoil water recharge.  

The demonstration effectively showcases how soil benefitting from carbon farming practices allows for optimal water infiltration, aggregate shape retention, and improved biological health all around. When disturbed through conventional practices like tillage, the soil can’t hold water in place, hurting farm trafficability and leading to a dry crust that will prevent proper moisture absorption throughout the growing season. 

Water infiltration is just one benchmark growers can use when testing soil health.