The first domesticated animal is widely believed to be: ((MCAER 2014))

✅Explanation: Leaching is the process by which soluble substances in the soil are dissolved and carried away by water, often leading to nutrient loss.

📌Other Options Explanations:
-B. Erosion involves the wearing away of soil by wind, water, or ice.
-C. Weathering is the breakdown of rocks and minerals due to exposure to weather elements.
-D. Percolation is the downward movement of water through the soil.

🔑Key Points:
-Leaching is the process by which water-soluble inorganic nutrients present in the topsoil get washed down into the lower soil horizons and get precipitated as unavailable salts.
– This process occurs due to excessive rainfall or irrigation, which causes the excess water to percolate through the soil and carry the nutrients with it.
-The nutrients that are commonly leached from the topsoil include nitrates, phosphates, and potassium, which are essential for plant growth.
– However, when they accumulate in the lower soil horizons as salts, they become unavailable to plants and can even cause soil salinization if the concentration becomes too high.
🛑Additional Information: 
– Fragmentation: It refers to the breakdown of organic matter into smaller particles by physical or biological processes. It does not directly affect the leaching of nutrients.
– Humification: It is the process of decomposition of organic matter into humus, which is a stable form of organic matter that improves soil fertility. It does not directly affect the leaching of nutrients.
– Decomposition: It refers to the breakdown of organic matter into simpler compounds by microorganisms. It can release nutrients into the soil, but it does not directly affect the leaching of nutrients.