Basic Soil Science: Soil Horizons Notes Date _______________Topic___________________________________ -----------------------------------------Notes-------------------------------------- -- Soil Horizons: ---------------------------------------------- ------------ Formulas Points, Key Ideas, Main ------------------------------------------- Why advocate? ----------------------------------------------------Summary of Main Ideas------------------------------------------------------- ------- Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons Notes -----------------------------------------Notes-------------------------------------- Subordinate Divisions: ---------- -------------------------------------- ------------ Horizon Boundary: Main Ideas, Key Points, Formulas Points, Key Ideas, Main ------------------------------------------- ----------------------------------------------------Summary of Main Ideas------------------------------------------------------- ------- Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.1 Horizon Matching Cards • “Organic” Horizon O • Does not have to be 100% organic matter material • thin O horizons • Do not occur in cultivated areas • Destroyed by plowing • Mineral soil • Dark color formed by Horizon A additional humus • Granular or fine blocky structure • Can be easily crushed • Thickness ranges from a few inches to more than 30 inches • Every cultivated agricultural soil has an A horizon • Important in maintaining soil fertility and favorable environment for root growth • Needs to be protected from erosion and compaction . Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.1 • Grayish brown to white color Horizon E • Not present in all Missouri soils • Occurs beneath an O or A horizon • Light in color because nearly all iron and organic matter have been removed • E for “eluviation” • Found in most forested soils and several prairie soils • Has noticeably less clay than the B horizon found beneath it • Layer that shows the most variation because Horizon B of soil forming processes that influence the soil • Can be bright yellowish-brown, reddish-brown, or red in color • Blocky or prismatic structure • Has more clay than other horizons • Clay films may be visible . Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.1 • Weathered Horizon C • Unconsolidated geological material below A or B horizon • Can dig with a spade • Not changed very much by soil-forming processes • Stands for “bedrock” Horizon R • Cannot easily dig with spade • Occur directly beneath any of the other master horizons Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.1 • Occurs between A and Horizon AB B horizons • Dominated by properties of A, but some B properties are still evident • Dark colors associated with organic matter are fading because organic matter is decreasing • Structure may change from granular to subangular blocky • Occurs between A and Horizon BA B horizons • More characteristics of B horizon than A • Structure is same type as B, but less strongly expressed • Color is a little darker than B or clay content may be less Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.1 • From B to C horizon Horizon BC • B properties are dominant, but some evidence of C is present • Clay content may be less than maximum in B, but more than in C • C is structureless, but C has structure Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.2 Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.2 Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.2 Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.2 Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.3 Horizon Smooth Boundary Abrupt Wavy Clear Irregular Gradual Broken Diffuse Transitional Boundaries Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.3 Subordinate AB horizon Divisions of Horizons BA horizon Oi horizon BC horizon Ap horizon Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.4 Soil Horizon Story Evaluation Create a story about soil horizons. Each master horizon (O, A, E, B, C, R) will be personified and assigned a character role. To personify the horizon means to attribute human characteristics to something nonhuman. Be sure each horizon’s name and human characteristics embody “who” the soil horizon would be if it were a person. Complete the table below to help create the story. Remember, a story has a beginning, middle, and end. This story needs to be at least 5 paragraphs and include all six horizons. Here are story themes to help spark ideas—western, romantic comedy, fantasy, science fiction, mystery, poetry, historical fiction, crime fiction, and satire. Soil Human Role in the Description of Horizon Name Horizon Characteristics Story O A E B C R AB BA BC Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.4 Story Title: ____________________________ Expectations: Description of each soil horizon completed accurately ______/15 A name is given to each horizon that embodies the horizon description ______/12 At least 3 human characteristics are listed for each horizon. ______/18 A story line is clearly developed and each character has an identified role in the story ______/18 The story has a beginning, middle, and end. Is at least 5 paragraphs in length ______/15 Strong and descriptive words are used ______/6 Correct grammar, punctuation, and spelling are used ______/10 Clearly and creatively applies elements of personification with success ______/6 Total ______/100 Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.5 Soil Horizons Evaluation Matching: _____ 1. Gradual changes from one master horizon to a. Pedon another b. Profile _____ 2. The smallest volume that can be called soil c. Horizon d. Organic matter _____ 3. Removal of soluble minerals from the soil by e. Transitional horizon movement of water through the soil over long f. Parent material periods of time g. Weathering _____ 4. A layer of soil that is approximately parallel to h. Erosion the earth’s surface i. Leaching j. Saturated _____ 5. The changing of rocks into soils _____ 6. The sum of all plant and animal material, living or dead, that is mixed into the soil _____ 7. When all the pores of a soil are full of water _____ 8. A vertical section of soil that allows you to see all the horizons that are present _____ 9. The original geologic material from which the horizons of a soil are formed _____ 10. Loss of valuable topsoil by the action of wind or water a. R horizon 11. _________ b. O horizon 12. _________ c. C horizon 13. _________ d. A horizon 14. _________ e. B horizon f. E horizon 15. _________ 16. _________ Basic Soil Science BSS4 Soil Horizons Basic Soil Science: Soil Horizons BSS4.5 KEY Soil Horizons Evaluation Matching: E 1. Gradual changes from one master horizon to a. Pedon another b. Profile A 2. The smallest volume that can be called soil c. Horizon d. Organic matter I 3. Removal of soluble minerals from the soil by e. Transitional horizon movement of water through the soil over long f. Parent material periods of time g. Weathering C 4. A layer of soil that is approximately parallel to h. Erosion the earth’s surface i. Leaching j. Saturated G 5. The changing of rocks into soils D 6. The sum of all plant and animal material, living or dead, that is mixed into the soil J 7. When all the pores of a soil are full of water B 8. A vertical section of soil that allows you to see all the horizons that are present F 9. The original geologic material from which the horizons of a soil are formed H 10. Loss of valuable topsoil by the action of wind or water a. R horizon 11. B b. O horizon 12. D 13. F c. C horizon 14. E d. A horizon 15. C e. B horizon 16. A f. E horizon Basic Soil Science BSS4 Soil Horizons .