Fertilizers

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Fertilizers

• Chapter 14

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Scotts Starter Fertilizer
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Scotts Turf Builder
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Fertilizers

• A materials applied to soil or plants to provide
  essential elements.
• Fertilizers can be
• Mineral
• Organic
• Inorganic
• Synthetic organic

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Seaweed Extract Fertilizer (Liquid)
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Mineral fertilizers

• Ground rocks, such as dolomitic lime
• Contains calcium
• Magnesium
• Low nutrient content
• Dissolve slowly
• Usefulness as a fertilizer is limited

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Mineral Fertilizer
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Organic fertilizers

• Animal manure
• Slow release
• Composted leaves
• Activated sewer sludge
• Low nutrient content
• Air/water benefit improves aeration and drainage
  and moisture retention

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Well Rotted Manure/ O.M.
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Release of Nutrient Ions
Organic
Dried Sheep manure
Mineral
inorganic
Decay
Nutrient ions Dissolved in the soil solution
Lime
10-10-10
Synthetic organic
Weathering
Dissolve
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Synthetic Organic

• Manufactured, but chemically organic
• Urea readily available
• Most other organics are slow release
• Nutrients high compared to natural

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Urea Fertilizer
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Inorganic Fertilizers

• Mined or manufactured
• Dissolve quickly
• High in nutrients

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Fertilizer Forms

• Pressurized liquid
• Fluids
• Dry fertilizers
• Slow release fertilizers

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Slow Release Fertilizers
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Pressurized Liquids

• Anhydrous ammonia is primary
• Gas at normal temp and pressure
• Liquid at 27 degrees F
• Stored in refrigerated tanks
• Injected into soil, evaporates
• Combines with water?breaks down

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Anhydrous Ammonia
Tank of Liquid ammonia
Direction of travel
Soil line
Chisel NH3
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Fluid Fertilizers

• Liquid, but not under pressure
• Solutions do not settle out
• Suspensions will settle out, so must be stirred
• Popular, easy to hand, many ways to apply

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Dry Fertilizers

• Applied to soil
• Dissolve quickly
• Pulverized, dusty, absorb moisture
• Granules, large evenly sized grains
• Prills, smooth round, dust free superior flow,
  coated

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Slow-Release Fertilizer

• Dry release slowly several weeks to months
• Too costly for agricultural use
• Used in greenhouse and nurseries
• Little lost from leaching
• Osmacote

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Greenhouse Slow Release Fertilizers
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Nitrogen Carriers

• Guano (bird and bat manure)
• Sodium nitrate
• Haber process gets N from the air
• 3H2N2?2NH3
• Anhydrous ammonia82 N
• Aqua ammonia
• Ammonium nitrate

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Guano A Source of Nitrogen
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Nitrogen Carriers (contd)

• Ammonium sulfate
• Nitrate of sodium
• Urea
• Urea-ammonium nitrate UAN
• Urea-formaldehyde UF, IBDU, SCU

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Nitrogen Carriers

• Anhydrous ammonia
• 82 N
• From Haber process
• Anhydrous means without water
• Cheapest strongest form of N
• Must be injected deep or will evaporate
• Dangerous for lungs

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Anhydrous Ammonia Application
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Nitrogen Carriers

• Aqua ammonia
• 20 N
• Dissolved ammonia in water
• Low pressure solution
• Use declining

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Nitrogen Carriers

• Ammonium nitrate
• 33 N
• ½ ammonium N, ½ nitrate N
• Good general purpose fertilizer
• Absorbs moisture and cakes
• Keep in enclosed containers/ bags

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Nitrogen Carriers

• Ammonium sulfate
• 21 N
• Acid forming since it contains S
• Good for acid loving plants
• Not good starter fertilizer
• Ammonium fertilizers must be mixed into soil by
  volatilization

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Nitrogen carriers

• Nitrate of soda
• 16 N
• Used on tobacco
• Raises pH because of Na
• Ca works similar but less salty

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Nitrogen Carriers

• Urea
• 46 N
• Synthetic organic
• Rapidly breaks down
• Cheapest to produce
• Most popular
• Hot dont over apply

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Nitrogen Carriers

• Urea-ammonium nitrate (UAN)
• Made by mixing liquid urea with ammonium nitrate
• Can make either 28 or 32 N

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Nitrogen Carriers

• Urea-formaldehyde (UF)
• (IBDU)
• Sulfur coated (SCU)
• Slow release synthetic organic
• Used for turf and greenhouse

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Nitrogen Carriers

• Carrier N NH4 NO3 pH
• Anhydrous 82.0 82.0 0 very A
• NH4NO3 33.0 16.7 16.6 acid
• NH4SO3 21.0 21.0 0 very A
• H2ONH4 24.0 24.0 0 acid
• NaNO3 16.0 0 16.0 basic
• CaNO3 15.5 0 15.5 basic

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Nitrogen Carriers

• Carrier N NH4 NO3 pH
• Urea 46.0 46.0 0 acid
• UAN 32.0 22.0 10.0 acid
• Urea Form. 37.0 37.0 0 acid
• Sulfur ctd 39.0 39.0 0 acid
• IBDU 30.0 -- - -

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The Haber process

• Carbon
• dioxide
• Ammonia
• Oxygen
• Sodium
• Carbonate
• calcium
• carbonate
• Sulfuric
• acid
• Phosphoric
• Acid

Urea Ammonium Nitrate Sodium Nitrate Calcium Nitr
ate Ammonium Sulfate Ammonium Phosphates Anhydrous
ammonia
UAN
Natural gas?N2?NH3
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The Haber Process
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Organic Fertilizers

• Material N P2O5 K2O
• Guano 10 4 2
• Blood meal 12 2 1
• Fish meal 10 6 -
• Cttn sd ml 6 3 1.5
• Soy bn ml 7 1.2 1.5
• Bone meal 3 22 -
• Wood ashes - 1 4

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Phosphate Carriers

• Obtained by mining rock phosphate in Florida
• From apatite or calcium phosphate
• Usually treated with acid to release P

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Phosphate Fertilizer
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Phosphate Carriers

• Rock phosphate 25-35 P
• Slow release
• Works best when finely ground and applied to acid
  soil
• Acid soils break down apatite

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Phosphate Carriers

• Superphosphate 20 P
• Made from rock phosphate and sulfuric acid
• ½ gypsum (calcium sulfate) and ½ calcium
  phosphate
• Not used much

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Superphosphate Fertilizer
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Phosphate Carriers

• P Carrier gt P2O5 P N
• Rock phosphate 25-35 11-15 -
• Superphosphate 20 8.7 -
• Triple phosphate 46 20 -
• Monoammonium 46-53 21-24 11-13
• Diammonium 46-53 20-23 18-21
• Ammonium phos 36-62 16-27 10-15
• Phosphoric acid 53 23 -

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Phosphate Fertilizers
70 Sulfuric Acid 90 Sulfuric Acid Phosphoric aci
d

• Superphosphate
• Phosphoric acid
• Treble superphosphate
• Rock phosphate

rock phosphate
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Phosphate fertilizers

• Superphosphate
• 46 P
• No sulfur or calcium
• Popular fertilizer
• Contains Fluorine, not good for many potted
  foliage plants

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Phosphate Fertilizers

• Phosphoric acid
• 53 P
• Highly corrosive
• Used to prepare fluid fertilizers

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Phosphate FertilizersAmmonium Phosphates

• Mix phosphoric acid and ammonia
• Makes monoammonium phosphate 53
• And diammonium phosphate 46
• Referred to as MAP and DAP
• Used as dry or fluid
• Ammonium polyphosphate similar
• Ammonium ions improves P uptake

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Phosphate Fertilizers

• Bone meal
• Contain phosphates and calcium
• By-product of meat packing
• Widely used by homeowners

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Bone Meal
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Potassium Carriers

• Mines are in New Mexico, Utah, California, and
  Canada
• A mixture of P, Na, an Mg salts
• Producers separate and purify

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Potassium CarriersMuriate of Potash KCl

• 60 P accounts for 97 of all K fert.
• Costs less
• Dissolves easily in water
• Sold primarily as dry fertilizer
• Not good for chlorine sensitive crops

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Potassium CarriersSulfate of Potash KSO4

• 49 K
• Used in dry fertilizer
• Primarily used for tobacco because tobacco is
  sensitive to chlorine
• Also adds sulfur to the soil

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Potassium CarriersNitrate of Potash KNO3

• 13 N and 44K
• Common for container plants
• Used dry
• Or weak solution

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Potassium CarriersSulfate of Potash-Magnesia

• Also used in chlorine sensitive crops
• 22 K, 11Mg, 22S
• Used in soils lacking Mg and S
• Wood ashes and manure are also good potash sources

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Potassium CarriersGranite Meal

• Dust by product of monument and building stone
  industry
• Used by organic growers
• Not readily soluble but slow reserve

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Potassium Carriers

• K carrier K2O N
• Muriate of potash 60 -
• Sulfate of potash 49 -
• Potassium nitrate 44 13
• Sulfate of K Mg 22 -

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Potassium CarriersSecondary Elements

• Mineral fertilizers supply most of Ca,Mg,S
• Most important fertilizers are lime, gypsum, and
  sulfur

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Common Sources of Secondary Elements

• Material Ca Mg S effect pH
• Calcitic lime 31.7 - - basic
• Dolomite 21.5 11.4 - basic
• Gypsum 22.5 - 12 neutral
• Hydrated Lm 46.1 - - basic
• Burned Lime 60.3 - - basic
• Magnesia - 55 - basic

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Common Sources of Secondary Elements

• Material Ca Mg S effect pH
• Mg sulfate - 11 14.5 neutral
• K Mg So4 - 11 22 neutral
• Flowers of S - - 30-100 acidic

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Trace Elements

• Each trace element is available in a number of
  different forms
• Sulfate salts are inexpensive and dissolve easily
  in water
• Or can be used dry
• FTE fritted trace elements
• Salts added to molten glass
• Glass ground to fine powder

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Trace Elements

• Chelates- special form of trace element that
  guards elements from being fixed in the soil
• Chelates are water soluble
• Mixing fertilizers is more convenient than
  applying each element separately

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Trace Elements

• El FTE SO4 chel other treatment
• B X borax BC borax
• Cu X X X oxide BC or BSO
• Fe X X X F chelate
• Mn X X X oxide BC or BSO4
• Zn X X X B chelate
• Mo X NaMo mx w/NPK,lime

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Iron Chelate
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Fertilizer Analysis and Grade

• Fertilizer analysis tells fertilizer elements and
  percent content
• Grade lists contents as three numbers
• NPK
• 0-0-60 means 60K in bag
• Potash 2000 x601200

100
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Fertilizer Analysis and Grade

• 20-10-20 means
• 20 N
• 10 P
• 20 K
• Grade may also indicate secondary elements
• Fertilizer grade never totals 100

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Fertilizer Analysis and Grade

• The bag may also contain fillers such as
• Sand
• Clay granules
• Limestone
• Corncobs
• Used to bring weight up to one ton

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Fertilizer Ratio

• Grade ratio
• 10-10-10 1-1-1
• 20-20-20 1-1-1
• 6-12-12 1-2-2
• 5-15-30 1-3-6
• Applying one ton of 10-10-10 is the same as ½ ton
  of 20-20-20-

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Elements and Oxides

• Most people think of fertilizer grade as N-P-K
• Nitrogen is listed as the element but P and K
  are listed as oxides
• N-P2O5-K2O
• In a 20-10-10 it appears that there is 200 of P
  per tonno! 88P per ton

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Elements and Oxides

• Oxide Element
• N 400 400
• P 200 88
• K 200 166

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Elements and OxidesConverting Between

• (a) P X 2.29 P2O5
• (b) P2O5 X ).44 P
• (C) K X 1.2 K2O
• (d) K2O X 0.83 K
• How much K in 0-0-60/ton
• K 2000 X 60 X 0.83 996

100
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Calculations for Blending

• Z AxB
• Z of carrier for each element
• A of mixed fertilizer needed
• B of element needed
• C of element in the carrier

C
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Blending

• Blend a 10-10-20 using
• Ammonium nitrate 33-0-0
• Triple superphosphate 0-46-0
• Muriate of potash 0-0-60

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Blending

• Ammonium nitrate2000 x 10 606
• Triple super P 2000 x 10 435
• Muriate of K 2000 x 20 667
• Total carriers 1708 292 fillers

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46
60
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Choosing Fertilizers

• Nitrates are preferred for early spring
• Nitrate produce a better tobacco leaf
• Ammonia is better for fall application because
  less will leach out by spring
• Ammonia is better for rice paddy because nitrate
  N converts to gas and is lost

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Choosing Fertilizers (contd)

• Container plants prefer nitrate because ammonia
  are easily damaged by ammonia
• Many acid loving plants prefer ammonium N
• Price per is another factor

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Pricing Fertilizer

• Price/lb N Price per ton x 100
• A ton of ammonium nitrate _at_ 200/T
• Price/lbN 200 x 100 .30 per lb N
• The price can also be figured per bag

2000 x N
2000 x 33
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Applying fertilizer

• Can be applied before, during or after planting
• In a fine soil with little leaching and high CEC
  one application may do, but
• P is not placed correctly for best results
• N may leach out before used

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Applying FertilizerIrrigated Corn, Sandy Soil

• Crop stage fertilization
• Preplant 1/6
• 8 leaves 1/6
• 12-15 leaves ½
• Early tassel 1/6

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Applying Fertilizer

• The best pre-plant is by broadcast
• Soil injection (liquids)
• Banding applied 2below and 1 to the side of
  seed
• Pop-up applied with seed, small amounts
• Should be water soluble, high P, low salt not
  produce free ammonia

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Applying Fertilizer

• Dilute fertilizer in water at transplant
• Topdressing, applied over growing crop such as
  grains, range, and turf.
• Side dressing is a fertilizer application along
  the plant row part way through the growing season

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Applying Fertilizer

• Fertigation is fertilizer injected into the water
  system
• Foliar feeding, applying fertilizer directly to
  leaves, usually a trace element such as iron

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Applying FertilizerFluids

• Knifed
• Foliar
• Fertigation
• Broadcast
• Banded
• Pop-up
• top-dress

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Applying fertilizersolids

• Broadcast
• Banded
• Pop-up
• Top-dress

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Applying FertilizerSlow-Release

• Top dress applications recommended

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Effects of Fertilizer on pH

• A fertilizer may be chosen to change pH
• P fertilizers do not cause lasting pH change
• Superphosphate do not cause change but phosphoric
  acid and ammonium phosphates are acidic
• Ammonium and urea lower pH
• Ca and Na nitrates raise pH

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Effects of Fert. on Soluble Salts

• Most fertilizers are salts
• High salts prevent germination
• A concentration of salts may burn
• Low watering can cause salt build up
• Intensive growing such as a greenhouse must have
  constant salt monitoring

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Effects of Fert. on Soluble Salts

• Fertilizer salt rel.sal anal. CCE
• Na NO3 100 100 16.5-0-0 36
• NH4NO3 105 49 35-0-0 -36
• NH4SO4 69 54 21-0-0 -107
• ANYHNH4 47 9 82-0-0 -36
• Urea 75 2 46-0-0 -36

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Effects of Fert. on Soluble Salts

• Fertilizer salt rel.sal anal. CCE
• Mono NH4P 30 13 12-55-0 -107
• Spr phos 8 17 0-20-0 0
• 3 x phos 10 9 0-46-0 0
• KNO3 74 24 13-0-46 36
• KCl 116 39 0-0-60 0

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Fertilizer Summary

• Fertilizer is a substance used to supply elements
  to plants
• The Haber process fixes N from the air into
  usable forms
• Fertilizers come in many forms
• Cost and effect are factors in deciding what to
  use