Lab_10 Soil Physical Properties

DIRECTIONS: There are 3 parts to this lab. Please read each part carefully. You will need to go to various sources for information and details. MATERIALS: Before you begin, be certain you have access to the Power Point presentation ( Lab #10: Soil Physical Properties) posted on Canvas and access to the internet (links are listed below in each part). PART 1. SOIL PHYSICAL PROPERTIES (19 Points) BACKGROUND: Soil texture is the percentage of sand, silt, and clay in soil. It is a very important property that affects many agronomic characteristics such as water holding capacity, infiltration rate, and fertility. Geologists generally classify soil based on the grain size of its mineral particles. These fall into three categories: Sand : gritty Silt : dusty Clay : fine and sticky. THE SOIL TEXTURAL TRIANGLE PRACTICE NOTES Step 1. How to read a Soil Triangle: Go to the following link http://www.youtube.com/watch?v=bAYzoVliNFQ Take some basic bullet points as you watch the video. (5 Points) Lab # 10: Soil Physical Properties 41 Points

Step 2. Read through Part 1 of the Power Point Presentation (Soil Physical Properties). You will need to view the PPT as a slide show to see the steps in determining soil texture. The PPT will have practice questions on how to determine soil texture. Answer questions A and B from the slides. Question A: _________________________ Question B: _________________________ Step 3. Use the Soil Texture Triangle to complete the following exercise. Soil Textural Triangle Practice Exercises % Sand % Silt % Clay Texture Name A 75 10 15 Sandy Loam B 10 83 7 C 20 20 70 Using your soil texture chart, determine the following soil textures using the percentages given. The first one has been done for you. % Sand % Silt % Clay Texture Name Example 75 10 15 Sandy Loam D 42 37 E 52 21 F 35 50 G 64 30 H 50 40 PART 2 SOIL STRUCTURE (10 Points) Go to the Power Point presentation Part 2. As you go through the slides answer the questions below and then take the quiz . a) What is the definition for soil structure? b) What is a ped?

What hydrologic groups (A, B, C or D) does this soil belong to? Is there a risk of flash flooding for structures built on this soil? Click on the pH and find out if this soil is acid (below 7), neutral (exactly 7) or alkaline (above 7). If you wanted to farm or garden on this soil, what should you add? (Adding lime makes soil more alkaline, adding peat moss makes it more acid and mushroom manure makes it more organic- rich.) 4. Now, let’s check out a soil in the bread -basket state of Kansas. Close the Bakersfield College soil map and put in the zip code 66616 (Topeka, Kansas). The soil map here shows numbers instead of names – click on 7214 and choose the Eudora soil to fill in the chart. Questions Answers How organic-rich is the topsoil here? (click on it to see a graph with percentage or organic matter) What does this soil have more of: clay or sand? Or are they about equal (click on each component and compare the two graphs) What hydrologic groups (A, B, C or D) does this soil belong to? Is there a risk of flash flooding for structures built on this soil? Click on the pH and find out if this soil is acid (below 7), neutral (exactly 7) or alkaline (above 7). Explain why soils like this make Kansas such a good place to farm. END of LAB