Colorado Agriscience Curriculum

Section: Plant & Soil Science

Unit: Soil Management

Lesson Title: Lesson 10: Use of Cropping Systems for Fertility Management

Colorado Agricultural Education Standards:

Standard 10.9 The student will demonstrate an understanding of soil fertility and its effect on crop production.

Colorado Science Standards:

Standard 7.0 Students know and understand common connections between scientific disciplines as well as connections between science and other academic areas.

Student Learning Objectives (Enablers)

As a result of this lesson, the student will:

1. Identify different cropping systems

2. Be able to explain sustainable agriculture

Time: Instruction time for this lesson: 50 minutes.

Resources: Plaster, Edward J., Soil Science and Management 3rd Edition, Delmar Publishing, Albany, NY, 1997

Tools, Equipment, and Supplies

Writing surface

Writing materials

Color overheads/Overhead projector/Computer with Powerpoint and projector and sound

Interest Approach

Lead a discussion about the students winning a large sum of money and what they would do with it. Then transfer into the discussion of being given a large sum of land and what would they do with it. This will then lead into objective one of different cropping systems and how to decide what to do with the land to optimize fertility management. ****Examples can be varied given the geographic area of the ag department. Instead of cropland and pasture, greenhouse space or anything else can be used where a decision has to be made for allocating resources.

When I say “spend it” I want you to get with a partner and tell them how you would spend a thousand dollars if someone gave it to you. Be ready to report back to the group. We will take 2 minutes for this exercise. Spend it!! Time is up, now report back and tell us how your partner would spend their money. Now when I say “Farm IT’ I want you to imagine you were just given 500 acres of cropland and 500 acres of pasture. What would you do with it? What would you grow, and how would you manage it for profitability? Discuss this with your partner and be ready to report back. Ready “FARM IT!”

Allow time to report back.

Just like you guys had to decide how to spend your money or what to grow, how do you think a producer decides what to plant, where to plant, and what to plant the following year? What factors help the producer make their decision?

There are many factors that lead a producer to a particular CROPPING SYSTEM. One factor is fertility management in the soil. That is what we are going to focus on as we look at cropping systems for fertility management.

Summary of Content and Teaching Strategies

Objective 1. Identify different cropping systems

Many cropping systems are listed and the teacher could employ many tactics to teach the differences of each type of system. Powerpoint slides are provided as a way of capturing information into notes.

Show power point slide #2

Continuous cropping

The same crop is grown on the same land each year. This allows a producer to grow the most profitable crop. They probably like growing that crop and have the proper equipment. From a fertility standpoint this is not a good strategy. Nutrients are depleted from the soil and more fertilizers then have to be applied. How is your performance as a student if you do the same task over and over? You get tired and then need more encouraging. This is the same with continuous cropping.

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Crop rotation

Not always the most profitable in the short run-but in the long run is better for soil fertility. This has become more popular as producers search for better uses of the land with less “man-made” inputs. Why not let the crops work for the land instead of the land working for the crop? Crop rotating benefits are:

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Control of disease and insect populations

By rotating away from a certain crop disease that normally prey on a certain crop can be cleansed from the soil. One example is rotating soybeans to wheat instead of continuously growing soybeans. This practice has reduced soybean cyst nematode damage by up to 90 percent.

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This practice also helps control weeds.

Some weeds flourish in one crop and perish in another. This reduces a herbicide treatments. Also some crops suppress weeds by allelopathy, where one plant emits a chemical that suppresses growth of another.

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Free source of nitrogen

Nitrogen fixing legumes (soybeans, alfalfa, peas) can be used to put nitrogen back into the soil for a crop that relies on nitrogen (corn, and wheat).

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Improve soil organic matter and tilth.

Using deep rooted plants like alfalfa improve subsoil.

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Improved soil erosion plan.

When using row crops, small grains, and forage crops.

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Crop Rotation Choices

Row Crops

Planted in wide rows to accommodate irrigation, mechanical and chemical weed control. Common row crops would be corn, sorghum, soybeans, edible beans, and cotton.

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Small Grains

Planted or sown in rows very close together. This allows for a faster ground cover. These types of crops also leave a large amount of residue that aids in organic matter maintenance and aid in soil conservation. These types of crops are good to begin a crop rotation system with.

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There are many crops that are best suited for particular environmental or soil conditions:

Wheat—dry areas with medium to fine textured soils

Oats—moister medium texture soils

Rye –prefers sandy soils

Barley—tolerant of saline soils

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Forages

Improve soil tilth, increase organic matter and aid in erosion control. Forages such as alfalfa fix nitrogen in the soil. Alfalfa has a long taproot and works well in breaking up soil hard pans.

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Double Cropping Systems

Double cropping is planting two crops to the same land area within one growing season. A common example is planting beans into wheat stubble.

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Advantages—eliminates seedbed prep for the final crop, less erosion problems, increased organic matter due to increased green matter of two crops.

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Disadvantages—two crops draw on more soil nutrients and available water—creates a greater management level.

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Dryland Farming

Farming in areas of low rainfall with no other supplemental irrigation.

Land is usually summer fallowed—harvested one year and allowed to rest the following cropping season. This give time to increase soil nutrients, and soil water. A fallowed field can store about 25 percent of the rainfall in the soil for the following crop.

GREAT CAUTION should be taken to avoid erosion problems, organic matter loss, and saline seeps (where saline water rises to the top of the fallow ground and leaves salt deposits) on fallowed ground.

Follow up objective one with an Eye Witness E-moment to solidify the information given in the notes. Allow time for review and to check for student understanding.

Objective 2. Explain Sustainable Agriculture

Transition from cropping systems to sustainable agriculture.

Now we are going to move into our second objective. I want you to turn to a partner and in the next minute come up with a definition for the work sustain. Ready go. Share your ideas. What does sustain mean?

Sustain means to support something and usually for a extended period of time. One of the recent buzz words in agriculture is sustainable agriculture.

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Sustainable agriculture is a philosophy of using ALL resources available to ensure that over the long term agriculture is still a viable industry. This means taking measures to protect resources while ensuing productivity. Top yields are not the goal, the goal is to have profitable yields based on REDUCED input costs.

Soil management (erosion and fertility management) is a crucial tool to a sustainable agriculture.

If time allows watching the movie on the hyperlink below is suggested. BE SURE TO PICK EPISODE 9. The entire movie is good, but 20 minutes long. It would be best to fast forward to the segment on the producer from Washington. It is the third segment.

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Now we are going to watch a video on sustainable agriculture. While the movie is going please take notes and make sure to find the areas of management that have changed that would be considered “sustainable practices.”

http://www.csrees.usda.gov/newsroom/partners/partners.html

Review/Summary.

Application

Extended classroom activity:

Have the students analyze any agriculture operation in the area and give suggestions for ways that more sustainable agriculture could be used.

FFA activity:

Take advantage of the new information and incorporate crop rotation or sustainable agriculture into a Ag Issues CDE.

SAE activity:

Members can analyze their own SAE’s or someone else’s in the chapter and give suggestions on how to make the operation more “sustainable.”


Evaluation ---Soil Management, Use of Cropping Systems for Fertility Management

Name__________________________

True or False

1. T F Continuous cropping involves using the same crop in a three year cycle.

2. T F One advantage of continuous cropping is that a profitable crop can be grown each year.

3. T F From a fertility standpoint, continuous cropping is very beneficial.

4. T F Crop rotation seeks to reduce the use of man-made inputs.

5. T F Insects can be controlled using crop rotation.

6. T F Allelopathy is controlled by using crop rotation.

7. T F Nitrogen fixing plants are called legumes.

8. T F Corn and wheat are legumes.

9. T F Deep rooted plants like alfalfa are bad for the subsoil.

10. T F Corn, soybean, and cotton are all “row crops.”

11. T F Small grains are a good crop to start crop rotation with.

12. T F Double cropping is planting two crops on the same land in the same growing

season.

13. T F Double cropping is bad because it creates too much green matter.

14. T F Soil nutrients and available water increase when double cropping.

15. T F Leaving land lay idle for one year is called fallowing.

16. T F The goal of Sustainable Agriculture is to produce the most yields as possible.

17. T F Sustainable Agriculture focuses on the long term goals of an operation.


Evaluation ---Soil Management, Use of Cropping Systems for Fertility Management

Name__________KEY________________

True or False

1. T F Continuous cropping involves using the same crop in a three year cycle.

2. T F One advantage of continuous cropping is that a profitable crop can be grown each year.

3. T F From a fertility standpoint, continuous cropping is very beneficial.

4. T F Crop rotation seeks to reduce the use of man-made inputs.

5. T F Insects can be controlled using crop rotation.

6. T F Allelopathy is controlled by using crop rotation.

7. T F Nitrogen fixing plants are called legumes.

8. T F Corn and wheat are legumes.

9. T F Deep rooted plants like alfalfa are bad for the subsoil.

10. T F Corn, soybean, and cotton are all “row crops.”

11. T F Small grains are a good crop to start crop rotation with.

12. T F Double cropping is planting two crops on the same land in the same growing

season.

13. T F Double cropping is bad because it creates too much green matter.

14. T F Soil nutrients and available water increase when double cropping.

15. T F Leaving land lay idle for one year is called fallowing.

16. T F The goal of Sustainable Agriculture is to produce the most yields as possible.

17. T F Sustainable Agriculture focuses on the long term goals of an operation.