1. Slope

2. Slope
Limits land use
Effects amount of water and the speed of water run off
Effects the degree of erosion

3. 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

4. Ways to measure slope
Clinometer
Transit Level
Abney Level
Laser Level

6. Soil Erosion Erosion Caused By: 1. Wind 2. Rain 3. Animals & humans
Which erosion is the most severe ?

7. Sheet Erosion
Can be fixed with tillage

8. Rill Erosion
Can be fixed with tillage

9. Gully Erosion
Cannot be fixed by tillage
Major cost to fix

10. Mineral Matter Particle Size
Sand mm in Dia
Silt in Dia
Clay < .002 in Dia
(can’t see with your eye)
Sand is 1000 times larger than clay

11. Pore Space The gap between soil particles which get filled with air and water

12. 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
Soil Aeration –
The exchange of air and soil from the atmosphere

13. 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 seen
Muck – fully decayed plants –
Both have 18% or higher O.M.

14. Soil Triangle

15. 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).

16. 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

17. Soil Structure 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

19. Soil Structure
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

20. Soil Structure
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