The major advantage of drainage in agriculture is

The major advantage of drainage in agriculture is removing excess water from the soil. Drainage helps to prevent water-logging which can lead to a reduction in crop yield or even crop failure. When there is excess water in the soil, it displaces the air in the soil pores, leading to the death of plant roots due to lack of oxygen. Drainage helps to create a balance between water and air in the soil, which promotes healthy plant growth. Additionally, excess water in the soil can lead to the leaching of nutrients, making them unavailable to plants. Drainage can help to prevent this by allowing water to move through the soil, carrying nutrients to the root zone where they are needed.