What should be integrated into irrigation system design to promote healthy root systems?

Integrating proper drainage into irrigation system design is crucial for promoting healthy root systems. Adequate drainage ensures that excess water can move away from the plant roots, preventing waterlogging, which can lead to root rot and other moisture-related issues. Healthy root systems require a balance of moisture and oxygen; when soil remains too saturated, roots may struggle to absorb necessary nutrients and can become weakened or diseased.

Additionally, effective drainage minimizes the risk of soil erosion and nutrient leaching, thus maintaining soil structure and fertility. By allowing excess water to flow away, a well-designed drainage system supports robust root development, ultimately enhancing plant growth and resilience against environmental stresses. The other options, while beneficial to various aspects of plant health, do not directly address the critical need for managing water levels around the root zone like proper drainage does.