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:

The correct answer is Both 1 and 2.

Key Points

• Humus is a dark-colored amorphous organic substance formed by the decomposition of plant and animal matter by microorganisms.
• It is colloidal in nature, which means it has a high surface area and the ability to retain and exchange nutrients, making it a critical reservoir of essential nutrients for plants.
• Humus significantly improves soil structure, enhancing aeration, water retention, and drainage capabilities of the soil.
• It plays a vital role in maintaining soil fertility by holding nutrients like nitrogen, phosphorus, and potassium in forms accessible to plant roots.
• Humus also contributes to the soil's ability to sequester carbon, which helps mitigate climate change.

Additional Information

• Formation of Humus:
  • Humus is formed during the process of humification, where organic matter undergoes decomposition by soil organisms.
  • It is a slow process and depends on factors like temperature, moisture, and the type of organic material present.
• Role in Soil pH Regulation: Humus has a buffering capacity, which helps in maintaining the pH of the soil, making it suitable for plant growth.
• Microbial Activity: The decomposition of humus releases nutrients and provides energy for soil microorganisms, promoting a healthy soil ecosystem.
• Physical Properties of Soil: The presence of humus improves soil texture, making it crumbly and easier to cultivate.
• Environmental Importance: Humus helps in reducing soil erosion by binding soil particles together and enhancing the soil's water-holding capacity.