What is the primary outcome of the process of mineralisation by microorganisms?

Release of inorganic nutrients from humus

The correct answer is Option (1): Release of inorganic nutrients from humus

The process of mineralisation by microorganisms refers to the decomposition of organic matter, such as detritus or humus, into simpler inorganic substances. During mineralisation, microorganisms break down the organic compounds present in humus and release inorganic nutrients.

Humus is a dark-colored, amorphous substance that is highly resistant to microbial action and undergoes decomposition at an extremely slow rate. It serves as a reservoir of nutrients, primarily organic compounds. Microorganisms involved in mineralisation break down humus and release the inorganic nutrients, such as nitrogen, phosphorus, and various mineral ions, that were originally present in the organic matter.

Option (2), which suggests the release of both organic and inorganic nutrients from detritus, is not accurate. Mineralisation primarily involves the conversion of organic nutrients into inorganic forms.

Option (3) suggests the release of organic nutrients from humus, but the main focus of mineralisation is on the release of inorganic nutrients rather than organic ones.

Therefore, the correct choice is (1) The humus is further degraded by some microbes and release of inorganic nutrients occur by the process known as mineralisation.