Soil organic matter, air encapsulation and water‐stable aggregation

SUMMARY A re‐interpretation of published data shows: firstly, that the hydrophobic properties of soil organic matter can increase the amount of air encapsulation within soil materials during water uptake; and secondly, that this increased air encapsulation can reduce water uptake rates sufficiently to prevent slaking. This aggregate stabilizing mechanism suggests novel approaches to soil management, based on the production of non‐uniformly distributed hydrophobic organic matter within intra‐aggregate pores, that could be used to improve soils whose aggregates fail when wetted rapidly.