Raw Humus

 Raw humus

A type of forest humus with a high C/N ratio (25-35, sometimes more), which is separated from the A horizon by a precise limit, usually containing acid and a high amount of carbon (52% or more).

Raw humus refers to organic matter in soil that is in the early stages of decomposition and has not yet fully broken down into its final, stable form. It is the partially decomposed organic material that contains the remains of plants and animals but still retains some of its original structure. This raw form of humus is not yet fully humified, meaning that the decomposition process is ongoing and the nutrients are not yet in a form that plants can fully absorb.

Key Characteristics of Raw Humus:

1. Partially Decomposed:
   Raw humus is not fully decomposed. It consists of organic matter that has been partially broken down by microorganisms and fungi but has not yet reached the final, stable humus stage.

2. Visible Organic Material:
   Unlike fully matured humus, raw humus may still contain visible plant fibers and other organic matter that hasn't been completely broken down. The material often looks more chunky and rough compared to fully humified humus, which is smooth and dark in color.

3. Color:
   Raw humus typically has a lighter color compared to fully mature humus, which is usually dark brown or black. Raw humus might appear as light brown, grayish, or greenish depending on the stage of decomposition.

4. Nutrient Content:
   While raw humus is rich in nutrients, these nutrients are not fully available to plants yet, because the decomposition process is incomplete. The nutrients are slowly becoming more accessible as the material further decomposes into fully humified humus.

5. Moisture Retention:
   Raw humus still has the ability to retain moisture in the soil, though this ability may be less effective than fully decomposed humus. It helps in improving the water retention and aeration of soil.

Formation Process of Raw Humus:

1. Organic Material:
   The process begins with plant and animal matter (such as fallen leaves, dead animals, and organic waste) entering the soil. This material starts to decompose through the action of microorganisms, fungi, and insects.

2. Microbial Breakdown:
   Bacteria, fungi, and other microorganisms begin to break down the organic material. This process is slow and may take months or even years, depending on the environmental conditions like temperature, moisture, and the type of material being decomposed.

3. Partial Decomposition:
   In the early stages, the material becomes partially decomposed, forming raw humus. Some parts of the organic matter are still recognizable, and the material is not as rich in nutrients or stable as fully decomposed humus.

4. Further Decomposition:
   With time, raw humus continues to decompose, and as the process progresses, it becomes more stable and turns into mature humus, which is fully decomposed and highly beneficial for soil health.

Role of Raw Humus in Soil:

• Soil Structure Improvement: Raw humus, even in its early stages, contributes to improving soil structure by making it more friable (crumbly) and improving aeration.
• Nutrient Source: Though raw humus is not as nutrient-rich as fully decomposed humus, it still provides a source of nutrients for soil organisms, which, in turn, help improve the overall nutrient content of the soil.
• Soil Moisture: It helps retain moisture in the soil, preventing it from drying out too quickly.

Raw humus is an important transitional phase in the decomposition process, as it continues to break down into mature humus, which is a key component in the soil that helps support healthy plant growth.