Texas FFA Nursery Landscape Practice Exam

An example of an organic material is:

1. Pea gravel

2. Perlite

3. Leaf mold

4. Vermiculite

The correct answer is: Leaf mold

Leaf mold is considered an organic material because it is derived from decomposed leaves and other plant materials. As leaves fall and accumulate on the ground, they undergo a natural decomposition process facilitated by microorganisms and fungi. This process transforms the leaves into a nutrient-rich, dark, soil-like substance that can improve soil structure, increase moisture retention, and provide essential nutrients for plants. In contrast, options like pea gravel, perlite, and vermiculite do not originate from plant or animal material and are therefore classified as inorganic materials. Pea gravel is a type of rock, while perlite and vermiculite are mineral-derived materials. Understanding the differences between organic and inorganic materials is essential in horticulture and landscape management, as organic materials play a crucial role in enhancing soil fertility and promoting plant health.