Understand the process of soil bioturbation
Did you know that in addition to solid mineral and organic particles, water and air, the soil also has a range of living organisms? Well, now we will explain how the organisms contribute to the formation as well as change the properties of the soil.
A series of physical and biochemical processes are associated with the genesis and fertility of soil, such as the bioturbation process (or pedoturbation).
Soil bioturbation is caused by the creation of channels and movement of mineral particles mainly by rodents, beetles, earthworms, ants and termites. The name of the process itself already indicates a lot: bio means life and turbation means stir, to disturb, to shake. This process of soil formation, of the category of translocation, alters the original structure of sediments and saprolites.
Another effect of bioturbation is the biological homogenization of the soil profile, which is contrary to vertical heterogenization associated with differentiation of the horizons by other soil formation processes. The homogenization is due to the movement of soil particles downwards or upwards. If earthworms are highly active by a sufficient long period, very deep superficial horizons with high organic carbon rates may develop, such as the Mollic epipedon.
In humid tropical regions, as Brazil, termites are extremely important to Oxisols genesis. Termites move soil particles from subsurface horizons to superficial layers, create very stable soil micro aggregates, galleries and channels, increasing soil porosity. Furthermore, termites also stimulate the decomposition of organic matter through the growth of fungi on plant material in especial chambers. Cutting ants do the same in areas near the subterranean nests. As the ants and termites only use particles of specific sizes (e.g. silt and fine sand), they also influence the particle size distribution in soils.
Soil is a complex ecosystem that depends, besides other factors, on organisms’ action to its proper development. In this context, practices that damage soil fauna are not desirable, for example, soil disturbance and the indiscriminate use of pesticides.
Soil bioturbation is a very interesting process, is not it?
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