Final answer:
Organic materials in soil contribute to water retention, nutrient absorption, and soil aeration, which are vital for plant growth; however, 'pest control' is not a direct function of organic material in healthy soil.
Step-by-step explanation:
The function of organic material in healthy soil that is not listed among the options provided is 'pest control'. The various benefits of organic matter in soil include water retention, nutrient absorption, and soil aeration. These functions contribute to soil health by offering absorption of nutrients for organisms, facilitating the exchange of gases, and maintaining soil structure, which influences the water and oxygen dynamics vital for plant growth.
Organic material in soil aids in breaking down organic matter into nutrient compounds that crops need for growth and maintaining soil texture. This is part of what is known as ecosystem services—processes that take place within ecosystems like soil ecosystems, due to the metabolic activities of the organisms living there, but also provide direct benefits to our food production systems. Pest control, while an important aspect of agricultural management, is not directly a function of the presence of organic material in the soil.