Certified Landscape Irrigation Auditor

What percentage of available water should be allowed for plants to withdraw before rewatering?

1. 30%

2. 50%

3. 70%

4. 90%

The correct answer is: 50%

The recommended approach for allowing plants to withdraw available water before rewatering typically aligns with the idea that maintaining a balance between water availability and plant health is crucial. Allowing approximately 50% of available water to be used before rewatering ensures that the root zone has sufficient moisture to support plant health while avoiding water stress. This practice encourages deep root growth and helps plants become more resilient by promoting healthy soil structure and microbial activity. If plants are allowed to withdraw too much water (for instance, 70% or 90%), they may face stress, which can lead to wilting and reduced growth. Conversely, rewatering too soon, at a lower threshold like 30%, may lead to overly saturated conditions, increasing the risk of root rot and other diseases. Therefore, allowing up to 50% of water to be withdrawn strikes a practical balance, ensuring that irrigation practices are both efficient and supportive of plant health.