Watson, Christian Jay P.Amoyen, Julius Caeasar M.Salazar, Joanne C.2026-07-102026-07-102020Watson, C. J. P., Amoyen, J. C. M., Salazar, J. C. (2020). Principles of Soil Science (CACC 105). [Instructional Materials, Don Mariano Marcos Memorial State University - North La Union Campus, Sapilang, Bacnotan, La Union]. Lakasa ti Sirib, DMMMSU Institutional Repository.https://lakasa.dmmmsu.edu.ph/handle/123456789/2142Module 1 Definition and Composition of Soil -- Soil defined: Edaphological and Pedological Approach -- Fields of Specialization in Soil Science -- Composition of the Soil -- Elemental Composition of the Earth's Crust and The Essential Nutrient Elements -- Module 2 Soil Formation and Development -- Soil Forming Rocks and Minerals -- Weathering, Soil Formation, and Soil Development -- Soil Profile -- Module 3 Physical Properties of Soils -- Definition of Physical Properties and Soil Texture -- Soil structure and soil densities -- Soil water and soil consistency -- Module 4 The chemical Properties of Soil -- Soil Colloids and silicate clays -- Factors Affecting Strength of Absorption of Ions in Soil Colloids -- Soil pH, Liming, Soil Salinity, and Sodicity -- Module 5 Soil Organism and Organic Matter -- Kinds of Soil organisms: Microorganisms and macroorganisms -- Beneficial activities of soil organisms and Nitrogen Transformations -- Effects of organic matter on soil properties -- Module 6 Soil Survey and Classification -- Soil taxonomy -- Soil surveyen-USLearning Object