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2/21/2020 Soil Water (Chapter 5) Notes - AGRI1050R50: Introduction to Soil Science (2020S)

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Soil Water (Chapter 5) Notes

Soil Water (Chapter 5) Notes

Did you know .... Did you know that only 3% of the water on earth is fresh water? And that soils play a very important part in the movement and filtering of water before we find it in our taps. Chapter 5 will start our discussion on water and soils and includes discussion of water's properties that make it so unique, energ of water movement in in soils, measuring water content in soils, and how water becomes plant available.

Lecture content notes are accompanied by videos listed below the notes in each submodule (e.g. Soil Water (Chapter 5) Videos A though C). Print or download lecture notes then view videos in succession alongside lecture content and add additional notes from each video. The start of each video is noted in parenthesis (e.g. Content for Video A) within each lecture note set and contains lecture content through the note for the next video (e.g. Content for Video B).

Figures and tables unless specifically referrenced are from the course text, Nature and Property of Soils, 14th Edition, Brady and Weil.

Content Video A

Soil Water

“When the well is dry, we will know the importance of water.” Benjamin Franklin

Water Trivia Only 3% of Earth’s water is fresh water. 97% of the water on Earth is salt water.

Water covers 70.9% of the Earth’s surface.

There is more fresh water in the atmosphere than in all of the rivers on the planet combined.

American residents use about 100 gallons of water per day

AGRI1050R50: Introduction to Soil Science (2020S) LH

2/21/2020 Soil Water (Chapter 5) Notes - AGRI1050R50: Introduction to Soil Science (2020S)

https://gotoclass.tnecampus.org/d2l/le/content/8094442/viewContent/60403374/View 2/6

American residents use about 100 gallons of water per day.

The first water pipes were made from wood.

More than 25% of bottled water comes from a municipal water supply, the same place that tap water comes from.

An inch of water covering one acre (27,154 gallons) weighs 113 tons.

Water makes up between 55-78% of a human’s body weight.

Data courtesy of USEPA

Structure and Properties Polarity

Hydrogen Bonding

Cohesion – Stick together

Adhesion – Stick to other materials

Hydration

Surface Tension

Capillary Action

2/21/2020 Soil Water (Chapter 5) Notes - AGRI1050R50: Introduction to Soil Science (2020S)

https://gotoclass.tnecampus.org/d2l/le/content/8094442/viewContent/60403374/View 3/6

Content Video B

It’s all about the ...... Energy HI to LOW

Relative not absolute values – Difference determines direction of movement

Potential – standard atmospheric pressure (bar) or Pascal

Gravitational

Osmotic

Matrix

Freedom of movement –Wet vs Dry Soils

Water Content and Potential

Measuring Soil Water

2/21/2020 Soil Water (Chapter 5) Notes - AGRI1050R50: Introduction to Soil Science (2020S)

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Movement of Water in Soils Saturated Flow

Heavy Rain - Fast

Hydraulic Gradient (Table 5.3)

Contamination and Loss - pesticides, nutrients , pathogens

Unsaturated Flow

Dominant movement of water

Texture

Driven by matric potential

Slow

Stratified Layer

Major textural change - Fragipan

Changes flow routes

Positive or Negative – Box 5.3

Vapor Flow

Wetting Front

2/21/2020 Soil Water (Chapter 5) Notes - AGRI1050R50: Introduction to Soil Science (2020S)

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Reflect in ePortfolio Download Print

Content Video C

Qualitative Descriptions Maximum Retentive Capacity – water saturated

Field Capacity

Plants with adequate water

Moisture is adequate but not too high for activities

Proper aeration for microbial community

Permanent Wilting Coefficient – Wilting Point

Hydroscopic Coefficient

Plant-Available Soil Water Texture

Organic Matter

Compaction

Roots

Capillary Action

Root Extension

Task: View this topic

Activity Details

2/21/2020 Soil Water (Chapter 5) Notes - AGRI1050R50: Introduction to Soil Science (2020S)

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