Methods of Applying Fertilizer

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Methods of Applying Fertilizer

• Chapter
• 7

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What to consider when selecting an application
method.

• Rooting characteristic of the crop to be planted.
• Crop demand for various nutrients at different
  stages of growth.
• Physical chemical characteristics of the soil.
• Physical chemical characteristics of the
  fertilizer material to be applied.

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• Availability of moisture.
• Type of irrigation system used if irrigation is
  the only, or major, source of water.
• Frequency and rate of irrigation water to be
  applied.

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Pre-Plant Applications

• Broadcast distributing over the top of the
  soil.
• Dry or liquid form.
• May be mechanically worked into the soil or
  incorporated by rainfall or irrigation.

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Drop Spreader

• Simple Fertilizer spreader inverted
  triangle-shaped hopper mounted between two
  wheels.
• -s small hopper size limits the load capacity
  field size it can be used on.
• s small size lends itself well to vineyards
  and orchards.

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Spinning-disc spreader

• A small bulk spreader pulled by a tractor or
  truck.
• Uses horizontal spinning disc to broadcast
  fertilizer.
• 20 40 swath
• -s easy to have skips or overlaps of fertilizer.

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Self-propelled spreader

• A large bin mounted on a large truck or a special
  3 or 4 wheel vehicle equipped with floatation
  tires ( reduce soil compaction)
• Can have simple horizontal-spinning-disc to
  air-flow applications
• Air-flow applicators have the capability to apply
  more than one fertilizer material at the same
  time.

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Liquid Spreader
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Liquid Spreader

• Tank, Pressure gauge, Regulator, Pump, Pipes,
  Hoses, Fittings, Nozzles, and a boom.
• Can be mounted on a truck, on a flotation vehicle
  or trailer, or directly on a tractor

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Organic Spreaders

• Similar to a spinning disc spreader.
• Normal to apply 5 20 tons per acre.
• Poultry waste is at a lower rate.

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Pre-Plant Applications - Injection

• Injection refers to placing fertilizers below to
  soil surface.
• All fertilizer that can be broadcasted on the
  soil can also be injected.

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How does injection take place?

• Drop pipes for liquids.
• Flexible tubes for dries.
• Channels are made by knives or shank openers
  mounted to the tool bar.
• This is best done after the soil has been plowed,
  disced or furrowed out and the soil is loose.

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Advantages of injections.

• Eliminates N gaseous losses.
• Reduces fertilizer losses caused by rain or wind
  erosion.
• Places the fertilizer directly in the root zone.

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Disadvantages of injection.

• Power requirements are greater.
• Some specialized equipment is required for some
  types of fertilizer. (Anhydrous ammonia)
• May disrupt the integrity of the beds.
• Liquids are harder to apply than dry.

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Applications at Planting

• Subsurface Banding (pop-up application)
• Appling fertilizer directly with the seed.
• Grain crops do well with this.
• Note use low rates of starter fertilizers
• Look at chart 7-1 found on page 168.

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Surface Banding

• Liquid fertilizers being applied to the soil
  surface directly above the seed.
• Sprinkler or rainfall need to move fertilizer
  down.
• Also used as an anti-crust. (acid serves to
  dissolve calcium carbonate crusts that impede
  crop emergence.)

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Post-Emergence Application

• Sidedressing refers to placement of fertilizer
  beside crop rows may be combined with
  cultivation.
• Both liquid and dry can be used.

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Topdressing

• Appling fertilizer to the soil surface after the
  crop emergence.
• The same equipment is used in the pre-plant
  broadcast applications

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Water-Run Application

• Savings in time, labor, equipment, fuel cost.
• May be pre-plant or post-emergence.
• Disadvantage to this type of application is
  uniformity of distribution and run-off water
  containing fertilizer.

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Irrigation Open Systems

• Ditches (lined or unlined)
• Gated pipe (used for furrow or flood irrigation)
• Both dry liquid fertilizers can be used.

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Irrigation Open Systems

• High-pressure center pivot, linear, and solid-set
  sprinkler systems.
• Low pressure drip, mist, micro-sprinkler
  irrigation systems.
• Not all dry liquid fertilizers are suitable for
  application in closed systems.

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Examples

• Aqua ammonia anhydrous ammonia due to the
  precipitates that may be formed if irrigation
  water high in calcium content.
• Plugging is a main problem in low pressure
  systems.

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Foliar Application

• Supplying nutrients during periods of peak demand
  when an immediate response is desired.
• Supplying certain nutrients, such as zinc, when
  soil or crop conditions are conductive to root
  uptake.
• Allowing precise timing of nutrient application
  related to the quality characteristics of the
  crop being grown.

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• Reducing nitrate leaching in certain cropping
  systems.
• Providing a source of nutrients to satisfy crop
  demand temporarily until a soil application can
  be made.

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Factors that may improve the effectiveness of
foliar nutrient.

• Application during early morning or evening
  hours.
• Application when temps. Are less than 850F.
• Relative humidity greater than 70
• Inclusion of a high quality adjuvant. (increases
  its effectiveness)

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Cont.

• Wind speed less than 5 miles per hour
• Application to young, actively growing tissue as
  compared to older, harden-off tissue.
• Application to expanding buds in perennial woody
  crops.

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Calibration of Application Equipment.

• Look at tables 7-3, 7-4, 7-5.