Partial preview of the text
Download Soils101_chapter_1_lesson_3 and more Cheat Sheet Science education in PDF only on Docsity!
Fundamental Concepts Lesson 3: SOIL After reading this lesson, the students should be able to: e Discuss a unified view of the soil as a medium for plant growth and asa natural resource. e Define and describe the physical, chemical, and biological properties of soil. e Describe the functions of soil. e Describe the importance of soil. Introduction Soil is one of the most important and indispensable natural resources of any country. Man's basic needs— food, shelter, and clothing—are directly or indirectly derived from the soil. For instance, rice, corn, vegetables, and other staple foods are directly derived fram the soil. Meat, pork, and eggs come from animals that feed upon the produce of the soil. Woods are grown from the soil, while nails, cement, and aluminum roofing are made of materials from the soil. The silk used for making clothes comes from silkworms that feed on mulberry leaves, which are grown from the soil. This lesson introduces the soil. General Definition Soil is a porous material made up of weathered rocks and minerals, and decom posed organic matter that forms on the Earth's surface. Some people also refer to this material as dirt when it's found in unwanted places, like on your clothes or under your fingernails. The properties of soil are influenced to varying degrees by climate, living organisms, and topography acting upon the parent material over time. On the other hand, soil refers to a three-dimensional natural bedy, similar to a mountain, lake, or valley. The soil is a collection of individual soil bodies that cover the land. Unlike the consistent peel of an orange, soil exhibits significant variations from one location to another worldwide. Each body of soil is like a tree in a forest, with different types of soils found in different landscapes. As one of the fundamental foundations of life on our planet, soil acts as a reservoir for water and nutrients. It serves as a medium for the filtration and decomposition of harmful waste materials and actively participates in the cycling of carbon and other essential elements within the global ecosystem. Natural Body The soil is a natural body that forms through the combined effects of decayed organic matter and the physical and chemical weathering of rocks and minerals in the presence of the natural environment. It develops in layers, each with its unique composition and properties, providing vital support for plant growth. Thus, the soil layer varies both in itself and from the underlying parent material. In many regions, a layer of loose debris called regolith covers the underlying unweathered rock. This layer can be formed locally or transported from other places and varies in thickness. Soil is created from regolith through the actions of living organisms, such as bacteria, fungi, and plant roots. This transformation takes place at the interface of rock, air, water, and living entities. Soil represents a remarkable blend of both destructive processes, including rock weathering and organic decay, and creative processes that involve the formation of novel minerals and organic-mineral compounds. A noteworthy consequence of these processes is the emergence of distinct layers known as soil horizons, which serve as distinguishing features setting soil apart from the deeper regolith. Dynamic Body The soil is a dynamic body because its composition and properties change with time and the environment influences soil conditions. For instance, young soil has composition and properties different from old soil. The soil has both static and dynamic properties: e Static properties are intrinsic to the material itself and are unaffected by any external variables. e Dynamic properties are manifested in the response of the body to externally imposed effects such as mechanical stresses tending to cause deformation and failure or the entry of water. 
