How can soil compaction and poor aeration exacerbate heat stress in turf during summer?

• A. Compaction reduces air-filled pore space, limiting oxygen to roots and slowing water movement, increasing drought sensitivity and heat stress; aeration improves air exchange and water infiltration
• B. Compaction increases infiltration and cooling
• C. Aeration worsens heat stress
• D. Heat stress is independent of soil structure

Answer: (A)

Soil structure determines how well roots can breathe and how quickly water can move to them, which is key for turf cooling in hot weather. When soil is compacted, air-filled pore space shrinks, leaving roots with little oxygen for aerobic respiration. That slows root metabolism and limits their ability to take up water, so even when you irrigate, the plant can’t transport water efficiently to the leaves. With less water reaching the shoots, transpiration—the main cooling mechanism in hot summer conditions—drops, so the turf heats up and becomes more stressed. Poor aeration also means water moves slowly through the soil and drainage is limited, compounding drought stress during heat spells. Aeration creates channels that restore air exchange and improve water infiltration and drainage, supporting healthier, more active roots that can sustain water uptake and continued transpiration, reducing heat stress. In short, compacted soil undermines root function and cooling, while aeration alleviates those problems.