What is the primary purpose of drainage systems in agriculture?

The primary purpose of drainage systems in agriculture is to remove excess water from the soil. Proper drainage is essential for maintaining optimal soil moisture levels, which promotes healthy plant growth. Excess water can lead to various issues, including root rot, soil erosion, and the leaching of nutrients, which can harm crops. By effectively managing water levels, drainage systems ensure that crops receive the right amount of moisture they need for healthy development while preventing waterlogging conditions that could be detrimental to root systems and overall plant health.

The other options relate to different aspects of soil and agriculture but do not reflect the main role of a drainage system. For instance, enhancing soil fertility and increasing soil temperature have more to do with soil amendments or management practices rather than the removal of excess water. Providing irrigation is also a function that is distinct from drainage, as irrigation involves the deliberate addition of water to support crop growth, while drainage focuses on the removal of surplus water.