Final answer:
Soil is a mixture of organic matter and fragments of rocks that provides a medium for plant growth and is composed of inorganic mineral matter, organic matter, water and air, and living organisms. Its composition varies widely and is influenced by several factors, including weathering of rock and decomposition of organic materials.
Step-by-step explanation:
What is soil? Soil is a key component of terrestrial ecosystems and can be defined as a combination of organic matter and fragments and dust of rocks. It forms the surface layer of the Earth, provides a medium for plant growth, and is composed of four major components: inorganic mineral matter, organic matter (humus), water and air, and living matter.
The inorganic material in soil includes particles of varying sizes, such as sand (0.1 to 2 mm), silt (0.002 to 0.1 mm), and clay (less than 0.002 mm in diameter). These materials are derived from the weathering of rock over long periods of time. The organic material, known as humus, comprises microorganisms, dead plants, and animals in various stages of decomposition, which improves soil structure and provides necessary nutrients and water for plants.
Loams are soils that contain a balanced mixture of sand, silt, and humus. The formation of soil is influenced by factors such as the chemical composition of soil, topography, living organisms, climate, time, and agricultural practices. With the ability to remove toxins from water and break down wastes, soil is not only critical for agriculture but also for environmental health and sustainability.