Calcium significantly improves soil by enhancing its structure, aeration, and water-holding capacity, ultimately contributing to better plant growth.
Here's a breakdown of how calcium benefits soil:
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Improved Soil Structure: Calcium acts as a flocculating agent, meaning it helps bind soil particles together. This is particularly important for clay soils, where calcium helps to aggregate the tiny clay particles into larger clumps. This process, called flocculation, creates larger pore spaces within the soil.
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Enhanced Aeration: The increased pore space resulting from flocculation improves soil aeration. Better aeration allows for more oxygen to reach plant roots and beneficial soil microorganisms. Adequate oxygen is crucial for root respiration and the activity of organisms that decompose organic matter and cycle nutrients.
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Increased Water Infiltration and Drainage: A well-structured soil with good pore space facilitates water infiltration and drainage. Water can penetrate the soil more easily, reaching plant roots. At the same time, excess water can drain away, preventing waterlogging, which can damage roots.
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Reduced Soil Compaction: Calcium helps to prevent soil compaction by maintaining a loose and crumbly structure. Compacted soils have reduced pore space, limiting aeration and water infiltration.
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Nutrient Availability: Calcium can influence the availability of other nutrients to plants. For example, it can improve the uptake of phosphorus, an essential nutrient for plant growth.
Impact on Sodic Soils:
Calcium is also used to remediate sodic soils, which are high in sodium. High levels of sodium can disperse soil particles, leading to poor soil structure and reduced permeability. Applying calcium (often in the form of gypsum) replaces sodium on the soil's cation exchange complex, improving soil structure and allowing the sodium to be leached away. As cited in the reference, maintaining an exchangeable sodium percentage (ESP) below 5% of the cation exchange capacity is vital for good soil structure and water-holding capacity.
In summary, calcium is a critical element for maintaining healthy soil structure, promoting aeration and water movement, and supporting optimal plant growth by improving nutrient availability.
