The question "What is humus 3?" is unclear as the provided reference describes humus as a single substance, and not different types or a numbered variety of humus. To best answer this, we can interpret the question in a couple of ways, and address each separately. The question can be considered:
- A misunderstanding of the term humus, and what the user actually wants to know is what humus is in relation to its function or characteristic?
- "Humus 3" is a specific term not explained in the provided reference.
Humus Explained Based on the Provided Reference
Based on the provided reference, humus is not a numbered entity and refers to a single substance.
It's defined as:
A substance created from dead leaves and plants, which, when added to the soil, helps plants grow. It's basically partially decayed organic matter.
Function of Humus
- Makes soil porous, which increases the soil's ability to hold both air and water.
- It is a great source of plant nutrients such as minerals.
If "Humus 3" is a Specific Term
If "Humus 3" refers to a specific type or classification of humus not covered in the reference materials, then I am unable to provide an answer with the information given.
The reference only explains the general term "humus," so I cannot identify any 'Humus 3' based on the document. Further information or context would be needed for this.
