Slope

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 % Rise over Run Organic matter always goes down hill

Ways to measure slope Clinometer Transit Level Abney Level Laser Level

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

Sheet Erosion Can be fixed with tillage

Rill Erosion Can be fixed with tillage

Gully Erosion Cannot be fixed by tillage Major cost to fix

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 clay

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

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

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.

Soil Triangle

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).

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

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

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

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