Transcript Powerpoint

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Section:
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Unit:
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Plant & Soil Science
Soil Management
Lesson Title: Use of Cropping Systems
for Fertility Management
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.
Crop rotation
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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.
Benefits of Crop Rotation
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Control of disease and insect populations
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By rotating away from a certain crop, disease
that normally prey on a certain crop can be
cleansed from the soil.
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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.
Benefits of Crop Rotation
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This practice also helps control weeds.
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Some weeds flourish in one crop and perish in
another.
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This reduces a herbicide treatments.
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Also some crops suppress weeds by
allelopathy, where one plant emits a chemical
that suppresses growth of another.
Benefits of Crop Rotation
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Free source of nitrogen
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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).
Benefits of Crop Rotation
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Improve soil organic matter and tilth.
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Using deep rooted plants like alfalfa improve
subsoil.
Benefits of Crop Rotation
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Improved soil erosion plan.
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When using row crops, small grains, and
forage crops.
Crop Rotation Choices
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Row Crops
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Planted in wide rows to accommodate
irrigation, mechanical and chemical weed
control.
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Common row crops would be corn, sorghum,
soybeans, edible beans, and cotton.
Crop Rotation Choices
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Small Grains
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Planted or sown in rows very close together.
This allows for a faster ground cover.
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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.
Crop Rotation Choices
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There are many crops that are best suited
for particular environmental or soil
conditions:
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Wheat—dry areas with medium to fine
textured soils
Oats—moister medium texture soils
Rye –prefers sandy soils
Barley—tolerant of saline soils
Crop Rotation Choices
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Forages
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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.
Double Cropping Systems
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Double cropping is planting two crops
to the same land area within one growing
season.
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A common example is planting beans into
wheat stubble
Advantages of Double Cropping
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Eliminates seedbed prep for the final crop
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Less erosion problems
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Increased organic matter due to increased
green matter of two crops.
Disadvantages of Double Cropping
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Two crops draw on more soil nutrients and
available water
Creates a greater management level.
Dryland Farming
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Farming in areas of low rainfall with no
other supplemental irrigation.
Dryland Farming
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Land is usually summer fallowed—harvested one
year and allowed to rest the following cropping
season.
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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.
Sustainable Agriculture
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A philosophy of using ALL resources available to
ensure that over the long term agriculture is still
a viable industry.
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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.
Sustainable Agriculture
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Watch the following episode (#9) on
different sustainable agriculture practices.
Segment 3 is the most applicable.
http://www.csrees.usda.gov/newsroom/pa
rtners/partners.html