Slaking is a form of structural degradation in which the soil particles separate and the top layer is compacted with smaller soil particles (clay and silt).

The fine particles form a dense hard layer called slake crust. This makes it more difficult for crops to germinate and develop a good root system. The risk of slaking is estimated by the mutual ratio of clay, silt, sand and organic matter in the soil. A very one-sided distribution (e.g., mainly sand or clay particles) poses the least risk of slaking, while a ratio of 10 to 20% clay poses the greatest risk of soil slaking.

The analysis Fertilizer Manager report includes a slaking figure. The higher the grade, the lower the risk of soil compaction.