The process that will not lead to the loss of nutrients from the soil is mulching.
Here's a simple explanation of each process:
Leaching: This occurs when water (often from rain or irrigation) washes away nutrients from the soil into lower layers, making them unavailable to plants. This can result in a significant nutrient loss.
Harvesting: When crops are harvested, the nutrients that have accumulated in the plants' leaves, fruits, and other parts are removed from the environment, thus reducing the soil's nutrient content.
Erosion: This is the process where wind, water, or other natural agents wear away and move soil and its nutrients from one location to another, often leading to a reduction of soil fertility.
Mulching: This involves covering the soil with materials like straw, leaves, or wood chips. Mulching can help to retain soil moisture, reduce erosion, and enhance nutrient content as the mulch decomposes. Therefore, rather than causing nutrient loss, mulching adds nutrients back into the soil.