Humus makes soil fertile primarily because it is rich in essential nutrients for plant growth and improves soil structure.
Here's a breakdown:
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Nutrient Reservoir: Humus is composed of partially decayed and partially synthesized organic matter. This organic matter acts as a storehouse of vital plant nutrients like nitrogen, phosphorus, potassium, and micronutrients. As humus decomposes further, these nutrients are gradually released into the soil in a form that plants can readily absorb.
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Improved Soil Structure: Humus improves soil structure by binding soil particles together. This creates larger aggregates, improving aeration and drainage. This granular structure enhances the soil's ability to hold both air and water, which are crucial for root growth and nutrient uptake.
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Water Retention: Humus has a high water-holding capacity. This means it can absorb and retain significant amounts of water, making it available to plants even during dry periods.
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Increased Microbial Activity: Humus provides a food source for beneficial soil microorganisms like bacteria and fungi. These organisms play a crucial role in nutrient cycling, further breaking down organic matter and releasing nutrients in plant-available forms. They also contribute to disease suppression in the soil.
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Buffering Capacity: Humus helps buffer the soil against drastic changes in pH, salinity, and toxins, providing a more stable and favorable environment for plant growth.
In summary, humus contributes to soil fertility by providing nutrients, improving soil structure, enhancing water retention, promoting microbial activity, and buffering against harmful conditions.
