What does the term 'Sorption' refer to in soil science?

In soil science, 'sorption' is a comprehensive term that encompasses both absorption and adsorption processes, treating them as a unified phenomenon. Absorption refers to the process where substances are taken up internally by a material, such as when water or nutrients are taken into the plant or the soil matrix. Adsorption, on the other hand, involves the binding of molecules, such as nutrients or contaminants, onto the surface of soil particles without being absorbed into the bulk of the soil.

By defining sorption this way, it acknowledges that these two processes can coexist and affect the availability of nutrients in the soil. Understanding sorption is critical for effective soil management and for optimizing nutrient uptake by plants, as it highlights how both the soil particle surfaces and the soil solution work together to influence nutrient availability.

The other choices focus only on singular aspects of the process or unrelated themes, which do not capture the full scope of what sorption entails in the context of soil science.