General Course Questions

Could you please explain what submergence potential is?

And is it the same thing as the hydrostatic potential that us mentioned in the textbook?

Submergence potential is a component of the total water potential and it is operational only in saturated soils. Submergence potential is formed in the same way as matric potential (operational in unsaturated soils) due to attraction between charged soil particles and polar water molecules and capilarity.

More on this topic can be found in your textbook in chapter 5

Hi, Maya. R the role in soil of mites and nematode just grazing on soil bacteria, and stimulate the nitrogen cycle? And does heterotrophic bacteria have any roles other than decompose organic matter? Thank you!

Nematodes (but not mites) feed on bacteria and due to their low N requirement nematodes release surplus of N into soil solution, which then becomes available to other organisms (including plants)

Mites perform other functions such as shredding & mixing of soil material, the also do a bit of burrowing. The can also enhance aggregate formation by ingesting mineral & organic soil particles.

Heterotrophic bacteria decompose organic matter and by doing that they help with the release of the available forms of N, S and P.

All soil organisms also add to the pool of soil organic matter once they die

Hi Maja, should we memorize the multiple steps of mineralization, I mean the chemical reactions of aminization, ammonification and nitrification?

you don't need to memorize the chemical reactions, but you should be able to describe them correctly