Soil Texture Pick up a handful of soil and you can feel how fine or coarse it is. That feel comes from the size and relative proportion of mineral particles in the soil, and is known as soil texture. The particles that make up soil are categorized into three groups by size: sand, silt, and clay. Sand particles are the largest and clay particles the Abstract. 1. Introduction: The term "soil" can have different m eanings, depending upon the field in which it is co nsidered. 2. Soil Mechanics. application as an engineering material. of organic constituents. Soil consists of a multiphase agg regation of solid particles, 3. Soil engineers: (PDF) Engineering Properties of Soils including soil descriptions, in 1902-1904, 1906, and 1914. The first USDA guide for soil horizon identification and description was released in 1937 (Bureau of Chemistry and Soils, 1937). Dr. Roy Simonson and others later summarized and revised this information (Soil Survey Staff, 1951; Soil Survey Staff, 1962). • Soil structure is dama ged (clay ionic structure impaired.) • Corrosion of foundations and pipelines • May release vapours and hydrocarbon into buildings and cellars • May create toxic dusts • May poison children playing in the area Methods to control Soil Pollution • Reducing chemical fertilizer and pesticide use. • Recycling is another way to reduce and control soil pollution. The life in the soil provides the foundation for successful farming, and for all terrestrial plant, animal, and hu - man life on Earth. A diverse community of soil bacteria, fungi, protozoa, worms, arthropods, and other organ - isms, commonly known as the soil food web, converts fresh residues into soil organic matter (SOM), and plays Soil types are classified in a hierarchy based on observations of soil properties from soil pits (up to 1.5 m deep). The number and arrangement of the layers that make up the soil (horizons) and their texture and colour are particularly important. The largest classification units (equivalent to species for plants/animals) are the major groups. SOIL MECHANICS Arnold Verruijt Delft University of Technology, 2001, 2006 This is the screen version of the book SOIL MECHANICS, used at the Delft University of Technology. It can be read using the Adobe Acrobat Reader. Bookmarks are included to search for a chapter. The book is also available in Dutch, in the file GrondMechBoek.pdf. Berhane Gebreslassie. By: Berhane Gebreslassie Soil Ecology Woldia University, Ethiopia October, 2016 f INTRODUCTION The roots of plants Microbial and animal biomass Mineral Soil materials Environment Organic matter In various states of decay as well as water and a gaseous atmosphere Uneven distribution of these components provides a great Soil is the unconsolidated mineral and organic matter mixed with liquid and gases. There are various elements by which soil characteristics differ from place to place and time to time. Viz. origin, Measures of soil quality such as capability and prime farmland are thought to reflect the inherent properties of soil in relation to crop production. Other soil quality criteria are needed for other uses of land. The potential capacity of a soil to function must be assessed before a soil's fitness for use can be measured (Mausbach, 1997). The process of soil description, classification, site quality and suitability evaluation 1 2. Slope positions in undulating and mountainous terrain 11 3. Slope forms and surface pathways 12 4. Relation of constituents of fine earth by size, defining textural classes and