Soil Science 1 2 2006 Rua Cambodia
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Transcript of Soil Science 1 2 2006 Rua Cambodia
Dr. Jan-Peter Mund (PhD Geographer)Faculty for Land Management and Land AdministrationRoyal University of Agriculture, Phnom PenhUniversity of Bonn and Mainz, Department of Geography, Germany
Soil Sciences Soil Sciences An Introduction to the ecosystem below usAn Introduction to the ecosystem below us
2006 2Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Content of the lecture on Soil Science
Introduction – Who is the teacher and What is learningWhat is a soil - Ecosystem and limited natural resourceSoil physics – Content, Structure, Fraction, Layers etc.Soil chemistry – Soil color, ph-Value, Soil organic matterSoil processes – Development, Weathering, FormationField practice in the surrounding of RUAWritten Test (1 hour)Soil fertility and organic matterSoil biology and biochemistry Soil as a source of plant nutrientsSoil survey and Soil classification methods Field practice Soil science in environmental managementSoil classifications and Soil regions of the world
Final exam
2006 3Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Content of the this lecture
1. Introduction2. Teaching method in this lecture3. What is learning ? - Background of
the learning and knowledge cycle
Question and answers – Break
4. What is a soil ?
5. General Introduction to the soil ecosystem
2006 4Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Introduction – Who is the teacher
My name is Jan-Peter Mund, please call me Jan.PhD Geographer (physical geography, geology, botany)Not married, no kids, living with my partner in Phnom P.University lecturer for physical geography, ecology and soil sciences.Expert in: Soil survey, GIS and mapping, Living in Cambodia since November 2003. Working as gtz/CIM advisor at the RUA (FLMLA).15 years research, teaching and working experience in developing countries in Africa south of the Sahara.Hobbies: Sports, travelling to foreign countries, music, literature and modern theatre.
2006 5Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
How I am going to teach this lecture
In English and sorry, not in KhmerEvery Wednesday afternoon in the classroom from 13:00 to 14:30 and from 14:45 to 16:00In a friendly and open minded atmosphereWith powerpoint presentations and field practise With open questions to the students during the lecturePlease ask me every expression you do not know !With open student discussions in the classWith questions and answers to check the student‘s learning progressAs a cognitive experimental learning processIn a way that you learn how to learn !
2006 6Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
What is the position of the teacher or trainer in the learning process
A teacher is someone who knows something and do not know a lot of other things.He knows exactly what he really knows and he knows well, what he do not know.That means, he knows where his know-ledge leaves off and is honest about it. A good teacher is able to explain what he knows and can motivate students to learn what they should know. The teacher has to be asked by the students for more detailed explanation, if they do not understand him. By the way, he increases the student’s active and passive knowledge of scientific matter and other subjects and things.
2006 7Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
What is learning as a process
Why learning is so important ?
The ability of any nation to compete successfully in a global market today
depends on the scientific, mathematical and critical literacy of its citizens.
The real voyage of discovery and learning consists not in seeking new landscapes
but in having new eyes.(Marcel Proust)
2006 8Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
What is learning as a process
What is learning ?Learning is the basic process of behavioural change.Learning is more than only repeating !It is a relatively permanent change in an organism’s behaviour due to experience and information.This ability to become increasingly more effective in solving problems as more problems are solved.Your task is now: To learn how to learn !
2006 9Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
The Experiential Learning Process
The "learn-by-doing" approach allows students to experience something with minimal guidance from the teacher.
Instead of being told "the answers," they are presented with a question, problem, situation, or activity which they must make sense of for themselves.
Learning by doing is called "experiential learning" because it is based on learning from experiences.
2006 10Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
The importance to ask questions !
Asking Questions: One of the most important roles of the teacher is to stimulate students to think about.
"Why?" and "How?" and "What if?“.
Asking open-ended questions along the way helps students to think about the problem.
This also provides opportunities to evaluate their experience and progress.
2006 11Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
The Experiential Learning Process
This is learningby doing
Experiencing
ReviewingPlanning
ConcludingDeciding
Implementing
2006 12Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
What is research? - A circled process
Find asolution
Review the problemtogether withthe solution
Recognizea problem
Understand the problem
Choosethe method
Analyze thequestions
The circle of research andunderstanding
2006 13Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Learning can be hard - We need a break !
15 Minutes break
And than we continue with the following points:
4.What is a soil ?
5.General Introduction to the soil ecosystem
2006 14Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Introduction - What is a soil ?
HabitusHabitus and Field surveyand Field survey Analytical workAnalytical workDescriptionDescriptionPresentationPresentation
Soil is a complex mixture of mineral matter, organic matter and living organisms.
For many years, soil was considered simply the loose fraction of the Earth's crust. It was around 1880, that soil was recognized as a natural body for the first time by the Russian scientist Dokuchaev.
Field Field
2006 15Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Introduction – Content of the 2nd part
What is a soilSoil definitions and viewpointsFactors and processes of Soil DevelopmentSoil horizonsSoil profileSoils – a limited resource in danger !Factors of Soil Degradation worldwide
2006 16Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
What is a soil ?
2006 17Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
We Study Soil Because It's A(n)
Great integratorMedium of crop production
Filter of waterand wastes
Producer and absorber of gases
Home to organisms (plants, animalsand others)
Medium for plant growth
Snapshot of geologic, climatic,biological and
human historySource material for construction, medicine, art, etc.
Essential limited natural resource of the earth
Waste decomposer
2006 18Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
How a soil looks like ? Some pictures
What is the color of these soils ?And why they have these colors ?
Red soil light brown dark brown
2006 19Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Soil is a complex mixture of mineral matter, organic matter and living organisms.Soils develop over time, sometimes very slowly in dry desert areas or more quickly in wet tropical regions.Many of our soils have been developing since the last 1 Mill. years and some others like lowland soils during the last 10 thousand years.The soil is different from "powdered rock" or "dirt" in that it supports life; in particular, the growth of plants.Soil can be thought of as the "skin" of the land; without it the land would die.Soil is in a dynamic equilibrium. It is always changing as a result of its interaction with the environment.
What is a soil ? - Definition
2006 20Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Soils are a complex three phase system composed of solids, liquids and gases with . The study of thephysical behavior of these phases is called SoilPhysics and includes::
Density and porosityTexture and structureColourWaterretention and movement
Soils are formed by weathering of "parent materials".These materials have many origins such as bedrock surfaces, marine (ozean), aolian (wind blown), lacustrine (from lake beds), alluvium (river) and organic (peat) deposits.
Definition of Soil phases
2006 21Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Soil horizons - Layer field analysis
2006 22Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Soil profile – Analytical Soil horizons
2006 23Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
SoilSoil DevelopmentDevelopment
Factors of Soil Development
Characteristics
Processes
Soil colori.e. colorisation throughSi, Al, Fe, Mn
Soil structurei.e. grains, prisma or pillarstructure
Organic Matteri.e. Mikroorganismen, Pilze
Content of calciumor lime as a result of weathered bedrock
pH-valueneutral, basic oralcalic Soil fraction classes
Stone, Sand Silt Clay Transformation WeatheringPutrefaction.Soil Mineral depletionSoil Mineral regrowthClay mineral regrowthWeathering of organic matterDevelopment of the soil structure
Translokations processesUpdwelling of saltTranslocation of clayTranslocation of organic matterBio-TurbationTranslocation of Si, Al, Fe, und MnTranslocationthe of topsoil layer
SoilSoil TypeType
ReliefHuman beingsTime
Bedrock
Vegetation
climate
Factors and processes of Soil Development
2006 24Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Soil profile development
2006 25Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
sandyDystricGleysol
Ap
Apg
Brg
Examples for soil research in the field
2006 26Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Catena A - less degraded -upper slope middle slope lower slope valley base
open tree savanna
Acrisol
no erosion
plinthicFerralsol
Cambisol
open to densetree savanna
densetree savanna
opentree savanna
shrubpatches
schematic soil depth
Complex Soil catena research on degradation
2006 27Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Catena B - degraded -upper slope middle slope lower slope valley basesingular trees
tussock grasses
no vegetationto
tussock grasses
closed dryforest patches
Leptosol
singular treestussock grasses
no vegetationto
open tree savannatussock grasses
shrubpatches
purerock
Leptosol
Leptosol
purerock
colluvialsediment
Ferralsol
rill and sheeterosion
colluvial sedimentation,gully erosionsevere sheet and rill rosion
schematic soil depth
Complex Soil catena research degradation
colluvialesHillwash-Sedimentüber Phlintosol
Soil erosion processes
Sheet- and rillerosion
2006 28Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Soils – a limited resource in danger !
Soil erosion in agricultural areas is one of the most dangerous trends worldwide.
Especially unadaptedagricultural land use systems as well as deforestation causes the major amount of yearly loss of topsoil in the inter tropical regions.
That leads a loss of more than 1.5 billion hectares of cropland worldwide.
2006 29Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
13%
14%
49%
24%
AfricaAfrica67,4%67,4%
29%
7%
35%
28%
1%
WorldWorld
EuropeEurope27,3 %27,3 %
34%
22%
35%
9%
OzeaniaOzeania and and Australia 18,1%Australia 18,1%
15%
61%
18%2% 4%
AsiaAsia 39%39%
38%
6%26%
27%
3%North America 28,4%North America 28,4%
32%
61%
3%
4%
22%
18%
14%
45%
1%
Central Central America 74,1%America 74,1%
South AmericaSouth America46,2%46,2%
41%
27%
26%
5%
1%
Source: World Ressources Institut 1995: percentage of eroded area in total
DeforestationCutting of fuel woodOvergrazingAgricultureIndustrialization
Factors of Soil Degradation worldwide
2006 30Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Students‘ assignment for next ThursdayTo next week you have to describe with your own words three different soils that can see on that picture:
2006 31Integrated Expert: Dr. Jan-Peter Mund (PhD Geographer)
Thank you for your kind attention
let’s learn together more about the endangered soils of Cambodia