The soil surface is the interface between the soil and the atmosphere. Its quality – roughness, porosity, stability – determines the rates of exchange of water and gases.
Visual assessment of soil surface quality (SSQ) can give an indication of soil health and soil function. A soil surface that has plenty of residue cover, presence of earthworm casts, and a rough, granulated structure will function much better than one that is sealed off. Soils with good surface quality will have higher water infiltration rates and lower risks of crusting and ponding.
Soil surface quality assessment is part of the optional Soil Structure Assessment module in the Soil Health Assessment and Planning tool (SHAP). To evaluate soil surface quality, use the SSQ score sheet below as a guide to rate the soil surface on a scale of 1-5. Select a score based on the description and photo that aligns closest to your observation. Intermediate scores (e.g., 2.5) may be assigned if the soil has characteristics of two score categories.
Repeat the assessment in at least three spots per site for a more representative result, and average these scores for a total site score.