Read the passage and answer the following questions:

The earthworm is often referred to as the farmer's 'friend' due to its beneficial role in the breakdown of complex organic matter and soil aeration. Similarly, decomposers play a crucial role in converting complex organic matter into inorganic substances like carbon dioxide, water, and nutrients through the process of decomposition. Detritus, consisting of dead plant remains (leaves, bark, flowers) and animal waste, serves as the raw material for decomposition. Decomposition involves several important steps: fragmentation, leaching, catabolism, humification, and mineralization. Detritivores, like earthworms, contribute to the process by breaking down detritus into smaller particles, which is known as fragmentation. Through leaching, water-soluble inorganic nutrients percolate into the soil horizon and precipitate as less accessible salts. Bacterial and fungal enzymes play a vital role in degrading detritus into simpler inorganic substances, and this process is referred to as catabolism. It's essential to understand that all these steps in decomposition occur simultaneously on the detritus. Humification and mineralization are significant processes occurring during decomposition in the soil. Humification involves the transformation of organic matter into stable, dark-colored substances like humus. Mineralization, on the other hand, refers to the conversion of organic nutrients into inorganic forms that plants can readily absorb.

Which of the following is not a characteristic of humus?

It is further degraded by the process of humification.

The correct answer is Option (4)- It is further degraded by the process of humification.

Decomposers break down complex organic matter into inorganic substances like carbon dioxide, water and nutrients and the process is called decomposition. Decomposition operate simultaneously on the detritus. Humification and mineralisation occur during decomposition in the soil. Humification leads to accumulation of a dark coloured amorphous substance called humus that is highly resistant to microbial action and undergoes decomposition at an extremely slow rate. It is rich in lignin and chitin. The humus is further degraded by some microbes and release of inorganic nutrients occur by the process known as mineralisation.