section:plant & soil science section:plant & soil science unit:soil management unit:soil...

Section:Section: Plant & Soil SciencePlant & Soil Science

Unit:Unit: Soil ManagementSoil Management

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

Continuous croppingContinuous croppingThe same crop is grown on the same The same crop is grown on the same

land each year. land each year. This allows a producer to grow the This allows a producer to grow the

most profitable crop. most profitable crop. They probably like growing that crop They probably like growing that crop

and have the proper equipment. and have the proper equipment. From a fertility standpointFrom a fertility standpoint this is this is

not a good strategy. not a good strategy. Nutrients are depleted from the soil and Nutrients are depleted from the soil and more fertilizers then have to be applied. more fertilizers then have to be applied.

Crop rotationCrop rotation

Not always the most profitable in Not always the most profitable in the short run-but in the long run is the short run-but in the long run is better for soil fertility. better for soil fertility.

This has become more popular as This has become more popular as producers search for better uses of producers search for better uses of the land with less “man-made” the land with less “man-made” inputs. inputs.

Benefits of Crop RotationBenefits of Crop Rotation

Control of disease and insect Control of disease and insect populations populations

By rotating away from a certain crop, By rotating away from a certain crop,

disease that normally prey on a certain disease that normally prey on a certain crop can be cleansed from the soil. crop can be cleansed from the soil.

One example is rotating soybeans to wheat One example is rotating soybeans to wheat instead of continuously growing soybeans. instead of continuously growing soybeans. This practice has reduced soybean cyst This practice has reduced soybean cyst nematode damage by up to 90 percent. nematode damage by up to 90 percent.


This practice also helps control weeds. This practice also helps control weeds. Some weeds flourish in one crop and Some weeds flourish in one crop and

perish in another. perish in another.

This reduces a herbicide treatments. This reduces a herbicide treatments.

Also some crops suppress weeds by Also some crops suppress weeds by allelopathy, where one plant emits a allelopathy, where one plant emits a chemical that suppresses growth of chemical that suppresses growth of another.another.


Free source of nitrogenFree source of nitrogen

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


Improve soil organic matter and tilth.Improve soil organic matter and tilth.

Using deep rooted plants like alfalfa Using deep rooted plants like alfalfa improve subsoil.improve subsoil.


Improved soil erosion plan.Improved soil erosion plan.

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

Crop Rotation Choices Crop Rotation Choices

Row CropsRow Crops

Planted in wide rows to accommodate Planted in wide rows to accommodate irrigation, mechanical and chemical irrigation, mechanical and chemical weed control. weed control.

Common row crops would be corn, sorghum, Common row crops would be corn, sorghum, soybeans, edible beans, and cotton.soybeans, edible beans, and cotton.

Crop Rotation ChoicesCrop Rotation Choices

Small GrainsSmall Grains

Planted or sown in rows very close Planted or sown in rows very close together. This allows for a faster ground together. This allows for a faster ground cover. cover.

These types of crops also leave a large amount These types of crops also leave a large amount of residue that aids in organic matter of residue that aids in organic matter maintenance and aid in soil conservation. maintenance and aid in soil conservation.

These types of crops are good to begin a crop These types of crops are good to begin a crop rotation system with. rotation system with.


There are many crops that are best There are many crops that are best suited for particular environmental or suited for particular environmental or soil conditions:soil conditions: Wheat—dry areas with medium to fine Wheat—dry areas with medium to fine

textured soilstextured soils Oats—moister medium texture soilsOats—moister medium texture soils Rye –prefers sandy soilsRye –prefers sandy soils Barley—tolerant of saline soils Barley—tolerant of saline soils


ForagesForages Improve soil tilth, increase organic Improve soil tilth, increase organic

matter and aid in erosion control. matter and aid in erosion control.

Forages such as alfalfa fix nitrogen in Forages such as alfalfa fix nitrogen in the soil. the soil.

Alfalfa has a long taproot and works well Alfalfa has a long taproot and works well in breaking up soil hard pans.in breaking up soil hard pans.

Double Cropping SystemsDouble Cropping Systems

Double cropping is planting two Double cropping is planting two crops to the same land area within crops to the same land area within one growing season. one growing season.

A common example is planting beans A common example is planting beans into wheat stubble into wheat stubble

Advantages of Double CroppingAdvantages of Double Cropping

Eliminates seedbed prep for the final Eliminates seedbed prep for the final crop crop

Less erosion problemsLess erosion problems

Increased organic matter due to Increased organic matter due to

increased green matter of two crops. increased green matter of two crops.

Disadvantages of Double CroppingDisadvantages of Double Cropping

Two crops draw on more soil Two crops draw on more soil nutrients and available waternutrients and available water

Creates a greater Creates a greater management management level.level.

Dryland FarmingDryland Farming

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

Dryland FarmingDryland Farming

Land is usually summer fallowed—Land is usually summer fallowed—harvested one year and allowed to rest the harvested one year and allowed to rest the following following cropping season. cropping season. This give time to increase soil nutrients, and This give time to increase soil nutrients, and

soil water. soil water. A fallowed field can A fallowed field can store about 25 percent store about 25 percent

of the rainfall in the soil for the following crop.of the rainfall in the soil for the following crop.

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

Sustainable AgricultureSustainable Agriculture

A philosophy of using ALL resources A philosophy of using ALL resources available to ensure that over the long term available to ensure that over the long term agriculture is still a viable industry.agriculture is still a viable industry. This means taking measures to protect This means taking measures to protect

resources while ensuing productivity. resources while ensuing productivity. Top yields are not the goal, the goal is to have Top yields are not the goal, the goal is to have

profitable yields based on REDUCED input profitable yields based on REDUCED input costs.costs.

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

Sustainable AgricultureSustainable Agriculture

Watch the following episode (#9) on Watch the following episode (#9) on different sustainable agriculture different sustainable agriculture practices. Segment 3 is the most practices. Segment 3 is the most applicable.applicable.

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

section:plant & soil science section:plant & soil science unit:soil management unit:soil...

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