Slope Limits land use Effects amount of water and the speed of water run off Effects the degree of erosion Measuring Slope Is the rise or fall in land per 100 Slope is always measured in ID: 579175
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Slide1
SlopeSlide2
Slope
Limits land use
Effects amount of water and the speed of water run off
Effects the degree of erosion Slide3
Measuring Slope
Is the rise or fall in land per 100’
Slope is always measured in %
Rise over Run
Organic matter always goes down hill Slide4
Ways to measure slope
Clinometer Transit Level
Abney Level
Laser LevelSlide5Slide6
Soil Erosion
Erosion Caused By:
1. Wind
2. Rain
3. Animals & humans
Which erosion is the most severe ?Slide7
Sheet Erosion
Can be fixed with tillage Slide8
Rill Erosion
Can be fixed with tillage Slide9
Gully Erosion
Cannot be fixed by tillage
Major cost to fix Slide10
Mineral Matter Particle Size
Sand .005- 2.0mm in
Dia
Silt .002 - .005 in
Dia
Clay < .002 in
Dia
(can’t see with your eye)
Sand is 1000 times larger than claySlide11
P
ore Space
The gap between soil particles which get filled with air and water Slide12
Soil Texture
The amount of sand, silt, and clay in the soil. Which indicates the
fineness
or coarseness
of the soil.
Why is texture important ?
Water holding Capacity
Nutrient holding Capacity
Permeability – the ability of air and water to move in the soil
http://
techalive.mtu.edu/meec/module06/Permeability.htm
Soil Aeration – The exchange of air and soil from the atmosphere Slide13
Soil Texture
Soil
Tilth
–
- The workability of the soil
How many different soil types are there ?
-
What is the most
desireable
type of soil ? Medium Texture which is called LOAM - Soil texture can limit which crops can be grown.
Ex carrots, onions (sandy) Corn – not sandy soils What is organic matter composed of ? Decomposed plants and animals which = Has high nutrients 2 kinds of O.M Peat – partially decayed plants some plant remains can be seenMuck – fully decayed plants – Both have 18% or higher O.M. Slide14
Soil TriangleSlide15
Soil Texture
Coarse textured soil
– soil that has a higher proportion of larger particles.
Coarse Texture-
Sand (S) , Loamy sand (LS), Sandy loam (SL).
Moderate
texture
– Sandy Loam (SL)
Medium
– Sandy clay Loam, (SCL) Clay Loam (CL), Silt Clay Loam (SiCL
)Fine textured soil – soil that has a higher proportion of smaller particles. Fine Textures - Clay (C), Silty clay (SiC), sandy (clay SC).Slide16
Determining Soil Texture by Hand
Soil, water, and hands
Damp
Damp, Damp soil Form a ball then a form a ribbon
< 2” loam – fat ribbon frayed ends
>2” clay – thin long ribbon
slimmy
Slide17
Most important indicator of soil development
Soil is not considered soil until aggregates are formed and they are really formed by organisms
Soil structure allows activities to happen on earth
5 types of soil structure shapes (aggregates)
Single Grained
Granular
Blocky
Plat
Massive
Soil Structure Slide18Slide19
Single grain
– loose sand,
part of C horizon
or parent material never developed into soil .Granular – smallest structure, but most stable occurs in the A horizon – granular = little disturbance and soil managed well.
Blocky
– resembles a cube – broken down in two categories (most common shape)
Angular Blocky – rounded edges
Subangular
Blocky – sharp edges
Soil Structure Slide20
Platy
–
not
good soil structure, compaction or parent material – restricts water flow (looks like pancakes) Prismatic – Prism shape – flat edges on all sides. Only be in the B horizon – if there is any
Massive
–
Absent of soil structure only found in C horizons – has no distinct edges
Soil Structure