Which of the following statements with reference to Humus is/are correct ? 1. It is a dark coloured amorphous substance. 2. Being colloidal in nature, it serves as a reservoir of nutrients. Select the answer using the code given below :

Humus is the end product of the decomposition of organic matter and is characterized as a dark-colored, amorphous (structureless) substance [1]. It is typically dark brown or black, which helps in warming the soil and imparting color to the topsoil [1]. Statement 2 is also correct because humus consists of tiny colloidal particles. Due to its colloidal nature and high surface area, it possesses a high cation exchange capacity, allowing it to bind to nutrients and water. This makes it a vital reservoir of nutrients, holding chemical elements in a form readily accessible to plants and sustaining soil fertility [1]. Therefore, both statements accurately describe the physical and chemical properties of humus in the soil ecosystem.

Sources

1. [1] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 6: Soils > Humus > p. 2