SLIDE SPECIAL ENGLISH FOR LAND MANAGEMENT

SPECIAL ENGLISH FOR LAND MANAGEMENT OBJECTIVE Developing language skills and able to use for major in land management, such as: Writing a report, reading article, communicating etc Introducing general knowledge of soil resources: Soil, Land Evaluation, GIS, Land use planning via foreign documents, newspapers, magazine Increase your academic vocabulary Which could be used for field of study CONTENTS THE ORIGIN AND COMPOSITION OF SOIL SOIL DEGRADATION LAND EVALUATION HUMAN IMPACT ON SOIL LAND-USE PLANNING GEOGRAPHIC INFORMATION SYSTEM SOIL FORMATION SOIL FORMATION Jenny (1941) and Dokuchaev Soil is formed as a result of the interaction of many factors, the most important of which are: WEATHERING Climate (cl) Organisms (o) Relief (r) Parent Material (p) Time (t) PROCESSES SOIL S = f(cl, o, r, p, t, …) What is Weathering? It is the process by which rocks on the earth's surface are broken down into pieces such as gravel, sand, silt and clay Chemical weathering, Physical weathering, Biological weathering SOIL COMPONENTS Soil is a complex mixture of minerals, organic materials, living organisms, air and water Soil Profile and Soil Horizons O horizon: the top layer of soil (organic layer) It's a thick layer of organic materials These materials give the soil nutrients that plants need to grow A Horizon: is also called the topsoil layer, rich nutrients (Plants, foods and trees growing) Organisms, such as ants, earthworms and rodents like rats and rabbits, live in this layer as well B Horizon (subsoil) is very hard and compact It is made up of broken down pieces of clay, organic matter and many minerals from the parent material in the level below Roots from larger plants can extend down to this level SOIL PROFILE C Horizon: Including parent material which has been weathered in the upper part Soil Texture and Soil Structure Both properties of the soil that will have a profound effect on the behavior of soils, such as water holding capacity, nutrient retention and supply, drainage, and nutrient leaching In soil fertility, coarser soils generally have a lesser ability to hold and retain nutrients than finer soils However, this ability is reduced as finely-textured soils undergo intense leaching in moist environments The texture of a soil is based on the percentage of sand, silt, and clay found in that soil The identification of sand, silt, and clay are made based on size Material Gravel coarse sand fine sand silt clay SOIL TEXTURE TRIANGLE Diameter (mm) more than 2.0 2.0-0.2 0.2-0.02 0.02-0.002 less than 0.002 GROUPS OF SOIL Sandy soil : Sand 85% Sandy loam: Sand 40 – 85%, Silt 0-50% silt, and clay 0-20% Silt loam : Sand 0-25% , Silt 50-88%, and clay 27% Loam soil: - Sand 23 – 52%, Silt 20-50% and clay 5-27% Clay loam : Sand 20-42% , silt 18-25% , clay 27-40% Sticky when wet Clay (heavy clay): sand less than 42%, silt less than 40% , clay 40% Very sticky when wet Translate into Vietnamese Soil Formation:- Living Organisms Plants, animals and micro-organisms (fungi and bacteria) all affect soil formation by producing or contributing to humus production The amount of humus in a soil is a result of how much plant material has been incorporated into it If vegetation is sparse a soil will be low in humus and less fertile Grasses have fibrous root systems that spread throughout the tiny pores of the soil - as the roots die and decay The soil becomes well supplied with humus Tree roots, being much larger than grass roots, not invade pores of the topsoil as completely, so the humus content of soils under forests is usually lower http://www.nzsoils.org.nz/Topic Basics_Of_Soils/Living_Organisms/ [...]... clay 27-40% Sticky when wet Clay (heavy clay): sand less than 42%, silt less than 40% , clay 40% Very sticky when wet Translate into Vietnamese Soil Formation:- Living Organisms Plants, animals and micro-organisms (fungi and bacteria) all affect soil formation by producing or contributing to humus production The amount of humus in a soil is a result of how much plant material has been incorporated... the roots die and decay The soil becomes well supplied with humus Tree roots, being much larger than grass roots, do not invade pores of the topsoil as completely, so the humus content of soils under forests is usually lower http://www.nzsoils.org.nz/Topic Basics_Of_Soils/Living_Organisms/