The Science of Maryland Agriculture

Transcription

1 The Science of Maryland Agriculture GOAL STATEMENT: Students will learn about soil as a natural resource, what its components are, how it is used, and whether it is renewable. OBJECTIVES: Students will collect, graph and analyze data. Students will explain how weathering creates soil. Students will explain what soil is used for and if it is renewable. REQUIRED MATERIALS Containers with different types of soil (sand, clay, organic matter) Copies of Soil Activity Data Sheet (1 per student) 1 quart jars or mayonnaise bottles (1 per group) Soil sample (1 per group) If collecting your own sample you will need a small shovel and bags to put the soil in Small white labels Water Stirring stick Materials for creating pie charts (compass, colored pencils, ruler) AMOUNT OF TIME TO ALLOW: 90 minutes; additional time is required to let the soil samples settle into their layers. Extension activities will take additional time. University of Maryland Extension programs are open to all and will not discriminate against anyone because of race, age, sex, color, sexual orientation, physical or mental disability, religion, ancestry, national origin, marital status, genetic information, political affiliation, or gender identity or expression.

2 Soil is a natural resource, just like air and water, and it s a very important one! Soil is the place where all terrestrial life begins. Most people consider soil to be just dirt, but it s much more than that. Soil is more than just a collection of particles. It is a complex body, an ecosystem all its own, and a dynamic substance that is constantly changing and reacting. Soil is considered a three-phase ecosystem because it contains solid, liquid, and gas phases. About fifty percent of the soil is solid particles both inorganic (or mineral) particles and organic matter. The inorganic particles of a soil are classified by size. The largest particles are called sand, the smallest particles are called clay, and the intermediate-sized particles are called silt. The specific combination of sand, silt, and clay particles in a soil determines that soil s texture. The other component of soil solids, the organic matter, is comprised of three parts: the biomass, residues and by-products, and humus. The biomass consists of all living creatures in the soil from organisms as small as bacteria to those as large as insects, plant roots, and even mammals like groundhogs. The biomass functions to create biopores, or channels within the soil, and serve important roles in nutrient cycling. Residues and by-products provide nutrients to the biomass and provide substances which promote soil aggregation or clumping. The last component of organic matter, humus, is the stable end product of decomposition. Humus does not provide the soil with nutrients, but it does contribute to the soil s ability to retain or store nutrients. Just as there are many different types of trees and flowers, there are many different types of soil. Some soil types are better suited to farming than others. Farmers are limited to using the land, and thus the soils, that they own. The amount of a crop that can be produced in a certain field is limited by the ability of the soil to grow that crop. Soil types cannot be changed, but the ability of a soil to produce a crop can be improved. Farmers often add amendments such as lime and fertilizer to help their crops grow better. 15 minutes How is soil created? To show how rocks and minerals become part of soil, take two rocks (one hard and one soft) and rub them together to demonstrate weathering, or the various mechanical and chemical processes that cause exposed rock to decompose. Show the students the resulting powder and chips on a sheet of paper. You can also pour water over the rocks and collect it to show the sediment that is worn away by rain. Inform the students that sediment will eventually become part of soil. Animal and plant matter which decays over time also contributes to the formation of soil. Different combinations of these elements determine the soil type. Show the students pictures of various extreme soil types: desert, clay, and fertile farming soil. Next, show students the various elements of soil (i.e. sand, clay, silt, organic matter) and ask them which they think is the largest portion of fertile soil (organic matter)? After they have made their guesses, talk about how soils are used in agriculture. University of Maryland Extension programs are open to all and will not discriminate against anyone because of race, age, sex, color, sexual orientation, physical or mental disability, religion, ancestry, national origin, marital status, genetic information, political affiliation, or gender identity or expression.

3 60 minutes Directions: 1. Divide the students into small groups. 2. Have the students take soil samples from different places around the school. If you don t have enough time, you can bring in the samples from anywhere. You can even use planting soil from the store. Also try mixing up different things like potting soil and sand. Anything will work as soils vary greatly even over small distances. 3. Assign a clear jar and soil sample to each group. Have them visually observe and write down what they notice about their soil samples (what they think it is mostly made of, what color, how much air is in it, is it compact, etc) 4. Have each group label their jar with where it came from or what the mixture is. 5. Fill the jar about a third of the way up with soil. 6. Add clean water until the jar is almost full. 7. Observe to see if any air bubbles rise and estimate how much air is in the soil. 8. Stir the mixture and leave the jar until it settles (this could take several minutes). 9. After the mixture has settled, ask the students to describe what happened and have the students measure and record each part of the soil on the It s Just Dirt worksheet. Usually mm work best 10. Ask the students to use the values for each of the categories to create a pie chart of their soil. Have each group share their completed pie chart with the class. After the mixture has settled, ask the students to describe what happened and have the students measure and record each part of the soil (usually mm work best). Sand, pebbles, silt, clay, water, organic material: Sand the heaviest layer and will be at the bottom. Pebbles these will be visible but will also be heavier and located at the bottom. Silt these particles are slightly lighter and will be the level above the sand. Clay these will be almost like little balls above the silt layer. Water it may be discolored with the decayed organic matter. Floating Organic Matter this will be on top and will be the organic matter that hasn t decayed yet. Ask the students to use the values for each of the categories to create a pie chart of their soil. Have each group share their completed pie chart with the class. 15 minutes Allow students to answer the analysis/conclusion questions within their groups. Use these questions to guide the class discussion. Talk about why the samples are different, where they came from, and which might be best for plants. Soils from paths that are frequently walked on could be very dense, and garden soil can be full of organic matter. Sandy soils don t hold water well; clay soil doesn t allow oxygen in as easily. Talk about soil as a resource. How is it used? Is it renewable or nonrenewable? Renewable University of Maryland Extension programs are open to all and will not discriminate against anyone because of race, age, sex, color, sexual orientation, physical or mental disability, religion, ancestry, national origin, marital status, genetic information, political affiliation, or gender identity or expression.

4 resources are things that can be replenished through natural processes. Nonrenewable resources are resources which cannot be produced, grown, generated, or used on a scale which can sustain its consumption rate. Most scientists actually classify soil as a nonrenewable resource because it takes a very long time to recreate soil. An interesting YouTube station filled with short videos on soils is by Dr. Clay Robinson. A great one using an apple is titled The Apple as Planet Earth. < Ask students to suggest possible ways that soil is conserved. Possible answers might include planting plants to anchor soil with roots, placing barriers around construction site and other loose dirt to catch runoff, creating windbreaks to stop soil from blowing away, no-till farming, etc. Have the students research what farmers do to conserve soil. You can contact the NRCS Natural Resources Conservation Service for more information: < Try growing seeds in each soil type and find out if the differences in the soils affected growth and development. Research what type of soils different plants like. You can also help the students find out what type of soils they have at their homes or around them by using NRCS Soil Surveys for Maryland found here: <websoilsurvey.nrcs.usda.gov> (You have to draw a box around the area that you want information on using the AOI red box tool in the toolbar then click on the soil map tab.) The Web Soil Survey program is challenging to use for those not familiar with the program; it is recommended that the teacher tries it before class and completes the survey on a projector with the class. Watershed Technician - Watershed technicians are specialists trained in conserving, enhancing and protecting watersheds and stream drainage basins. They study the contours of a given area of land and, using scientific instruments, determine how water flows through, and perhaps beneath, that section of land. Watershed technicians also work with ecologists in planning water retention features, such as ponds, streams and drainage fields, to minimize the impact on the ecology of the area Environmental Technician - An environmental technician monitors the environment and investigates sources of pollution by performing laboratory and field tests. Soil Conservationist - officers who plan the application of total resource management systems and provide conservation planning assistance from initial evaluation to completion. Soil conservationists possess a practical knowledge of the methods and techniques of soil, water, and environmental conservation as they relate to agricultural operations and land use measures. These personnel also help landowners with issues such as dealing with soil, water, air, plants, and animal resource concerns. County Agriculture Agent - provides leadership in determining, implementing, and evaluating educational programs which are designed to solve social, economic, and University of Maryland Extension programs are open to all and will not discriminate against anyone because of race, age, sex, color, sexual orientation, physical or mental disability, religion, ancestry, national origin, marital status, genetic information, political affiliation, or gender identity or expression.

5 environmental problems in agriculture and natural resources. The agent is an educator, an information provider, a needs assessor, a problem solving resource for clientele, and networks with the agricultural industry, specialists, Extension agents and agency representatives. Crop Consultant they help farmers make better management decisions based on advice provided on a variety of topics. Crop consultants scout fields for diseases and insects during the growing season and provide farmers with information and recommendations regarding the need for treatment to prevent economic loss. They may collect soil samples in order to provide recommendations on the application of fertilizers. Consultants also provide irrigation advice and are becoming more proficient in the emerging area of precision farming. Conservation Planner work with land owners to create a plan that outlines conservation practices and systems a land owner intends to use, develop and maintain on their property. The plan involves all of the natural resources (soil, water, air, plant, and animal resources) on the property. A pre/post test should be completed with the lesson plan. Student understanding of concepts can also be evaluated through class discussion as well as through evaluation of completed activity data sheets. Analysis/ conclusion questions that are answered incorrectly by a large number of students should be addressed in a follow-up discussion. United States Department of Agriculture, Natural Resource Conservation Service. < What is Soil? Soil-net.com. < Dr. Dirt K-12 Teaching Resource. < Soil Profile. ThinkQuest.org. <library.thinkquest.org/j003195f/newpage5.htm> University of Maryland Extension programs are open to all and will not discriminate against anyone because of race, age, sex, color, sexual orientation, physical or mental disability, religion, ancestry, national origin, marital status, genetic information, political affiliation, or gender identity or expression.

6 Name: Date: Period: Goal: Observe the different components of soil and compare and contrast different types of soil. Materials: clear pint or mayonnaise jar soil sample water and stir stick ruler, compass, colored paper Background: Soil along with air and water make up the earth s 3 natural resources. Without soil we couldn t grow the plants that provide us oxygen or the plants that we and other animals consume for food. We often think of soil as one thing, but it is actually made up of many parts including: sand, clay, silt, organic matter, water, and animals that live in soil. The amount and concentration of these different elements combine to give us what we classify as a soil type. Different soil types are better suited for growing plants than others. Directions: 1. Get into your lab group. 2. Listen carefully as the teacher explains the activity. 3. Fill your jar a third of the way full with your soil sample. 4. Fill your jar the rest of the way full with water. Observe what happens. 5. After a minute take your stir stick and stir up the sample. Put the lid on and shake the sample several times. 6. After the sample has settled use a ruler to measure out in (mm) each layer. 7. Sand the heaviest layer will be at the bottom. 8. Pebbles these will be visible but will also be heavier at the bottom. 9. Silt these particles are slightly lighter and will be the level above the sand. 10. Clay these will be almost like little balls above the silt layer. 11. Water it may be discolored with the decayed organic matter. 12. Floating Organic Matter this will be on top and will be the organic matter that hasn t decayed yet. 13. Measure the different levels and record the heights in mm. 14. Use your data to make a pie graph showing the proportions of each of the components in the soil sample. The Science of Maryland Agriculture

7 Name: Date: Period: Analysis: Write a brief description of what you observe about your soil sample (color, density, what s in it, etc). Soil Pie Chart 1. Record the values for each of the layers in the chart provided in the Height of Layer column. 2. Find the total height of the jar and record Total Height 3. Find the percentage for each portion of the soil by dividing its layer height by the total height. (It should be a decimal like.45 which would mean 45%) 4. Find the angle for the both sides of the pie section. Take the percentage for each slice and multiply it by If you have done it correctly all the number should add back up to Draw a line to make the radius of the circle. Start in the exact center of the circle and draw a straight line to the outside of the circle. 7. Draw each section division. Draw the sections by marking the first division against the edge of the protractor at the correct angle, using the angle formulations you got in the earlier step. Each time you add a section, the radius changes to the line you just drew; rotate your protractor accordingly. 8. Color each segment a different segment to match your key color. Soil Component Height of Layer (mm) Layer height / Total height Sand Pebbles Silt Clay Water Floating Organic Matter Total Height: The Science of Maryland Agriculture

8 Name: Date: Period: Soil Sample Pie Graph Pie Chart Color Key Sand Pebbles Silt Clay Water Floating organic material Describe the difference between your soil sample and others from your class. Which do you think would be the best for growing crops and why? The Science of Maryland Agriculture

9 Name: Date: Period: Conclusion: Weathering creates soil particles from rocks over time. Explain the process of weathering. Soil is made up of several different things. What are the major components that make up soil? Explain what other human activities can use up soil other than agriculture. Soil is a natural resource. Explain how this natural resource is used up over time. The Science of Maryland Agriculture

10 The Science of Maryland Agriculture PRE-Evaluation: It s Not Just Dirt 1. How old are you? 2. Are you... (Select one.) A boy A girl 3. Are you.(select ALL that apply.) African American/Black Asian Other Native American/Alaskan Native Hispanic/Latino White Native Hawaiian/Other Pacific Islander 4. What type of school do you go to? (Select one.) Public school Private school Religious school (Catholic, etc.) Home school Your Science and Agriculture Opinions and Knowledge 5. BEFORE going through the AGsploration Program, please circle the degree to which you agree or disagree with the following statements. Strongly Disagree Disagree Agree Strongly Agree I like science I feel that Maryland agriculture is a part of science Science is useful for solving everyday problems Maryland agriculture is beneficial to me, my family, and my community. When I graduate from high school, I would like to have a job in agricultural science I can name three jobs in the agriculture industry BEFORE going through the AGsploration Program, please circle your knowledge level about the topics listed below. Very None Low Medium High High Maryland agriculture Weathering Types of soil Soil components Non-renewable resources

11 The Science of Maryland Agriculture POST-Evaluation: It s Not Just Dirt Your Science and Agriculture Opinions and Knowledge 7. AFTER going through the AGsploration Program, please circle the degree to which you agree or disagree with the following statements. Strongly Disagree Disagree I like science I feel that Maryland agriculture is a part of science Science is useful for solving everyday problems Maryland agriculture is beneficial to me, my family, and my community. When I graduate from high school, I would like to have a job in agricultural science. Agree Strongly Agree I can name three jobs in the agriculture industry AFTER going through the AGsploration Program, please circle your knowledge level about the topics listed below. None Low Medium High Very High Maryland agriculture Weathering Types of soil Soil components Non-renewable resources As a result of participating in this activity, tell one new thing you will try or one thing you will find information about.

12 The Science of Maryland Agriculture SUPPLEMENTAL-Evaluation: It s Not Just Dirt Directions: If you are teaching more than one lesson plan in one day, you may attach this to the pre/post evaluation form for the other lesson you are teaching. Please have the student fill out these during the pre and post evaluation times. In addition, only have the student fill out the post evaluation questions Q5 Q7 at the completion of all lessons. PRE-Evaluation BEFORE going through the AGsploration Program, please circle your knowledge level about the topics listed below. None Low Medium High Very High Maryland agriculture Weathering Types of soil Soil components Non-renewable resources POST-Evaluation AFTER going through the AGsploration Program, please circle your knowledge level about the topics listed below. None Low Medium High Very High Maryland agriculture Weathering Types of soil Soil components Non-renewable resources