Micronutrient fertilizers and their properties

1. MICRONUTRIENT
FERTILIZERS AND THEIR
PROPERTIES
Sumeena K J
2018-11-109
Dept. Soil Science and
Agricultural Chemistry
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2. MICRONUTRIENTS
 Nutrients required in trace amounts for the normal growth
and development of plants.
 Micronutrients:
Iron (Fe),
Zinc (Zn) ,
Manganese (Mn),
Copper (Cu),
Chlorine (Cl),
Boron (B),
Molybdenum (Mo), and
Nickel (Ni)
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3. IRON FERTILIZERS
 These are generally water soluble substances,
predominantly sprayed as foliar nutrients on the crops.
 Plants absorb iron in the form of Fe2+
 The following kinds of iron fertilizers are available
1. Inorganic iron fertilizers
2. Iron frits.
3. Synthetic iron chelates
4. Natural organic complexes
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4.  1. Inorganic iron fertilizers
- contain 14-77% Fe
Ferrous sulphate [FeSO4.7H2O] (19%)
- it is most widely used
Ferric sulphate (23%), Ferrous oxide (77%), Ferric oxide
(69%), Ferrous ammonium sulphate (14%) , Ferrous
ammonium phosphate (29%) etc.
 2. Iron frits.
Fritted glass (20-40% Fe)
- suitable for acid soils
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5.  3. Synthetic iron chelates
- contain 5-14% Fe
- they are more effective but expensive.
Na Fe EDTA(5-14%), Na Fe EDDHA(6%)
Na Fe DTPA(10%) , Na Fe HEDTA(5-9%)
 4. Natural organic complexes
- contain 5-10% Fe
Iron polyflavanoid (9-10%) , Iron lignosulfonate (5-8%)
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6. ZINC IN FERTILIZERS
 Zinc fertilizers are of different kinds as follows
1. Inorganic Zn fertilizers viz. ZnSO4.7H20
2. Zinc-glass frits
3. Zinc chclates viz. Zn EDTA
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7.  Inorganic zinc fertilizers
 1.Zinc Sulphatc (ZnSO4.7H20.)
- It is known as white vitriol
- It is colourless, crystalline and readily soluble in water
- It contains minimum 21% Zn and 1% S (as per FCO,India)
- Its use is wide sprcad. Because it is easily available,
relatively cheap and readily soluble in water
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8.  Zine sulphate monohydrate [ZnSO4.H2O]
- It contains minimum 33% Zn (as per FCO)
- It can be soil applied or foliar sprayed. Soil application is
more effective than foliar application.
- To correct Zn deficiency one spray is not sufficient Several
sprays are necessary.
For water logged rice, soil application of zinc sulphate after
flooding was more effective than application before flooding.
- ZnSO4 should be applied at close proximity of roots.
Becausc, Zn becomes immobile after application to soil. It
necessiates incorporation of ZnSO4 with soil.
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9.  3.Zinc Carbonate (ZnCO3).
- It is white, amorphous and insoluble in water. But in
soil it dissolves slowly.
- It contains 52% Zn.
 4.Zinc oxide (ZnO).
- It is white, amorphous and insoluble in water. But in
soil it dissolves slowly.
- If applied in granular form in soil it can not immediately
supply sufficient Zn to plants. Thus, its immediate
effectivencss is low.
- It contains 78% Zn
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10.  4. Zinc sulphide (ZnS)
- It is white and insoluble in water.
- Contains 67% Zn
 5. Zinc phosphate ( Zn3(PO4)2 ).
- It is insoluble in watcr.
- It contains 51% Zn.
 6. Zinc Oxysulphate
- It is produced by partially acidulating ZnO with H2SO4.
- It is composed of ZnO and ZnSO4
- It contains 40-55% Zn. The % water soluble Zn in this
fertilizer depends on degree of acidulation.
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11.  7 Ammoniated zinc sulphate
- It is an inorganic complex.
- When added to soil this complex decomposes to yield
Zn2+ ions that are absorbed by plant roots.
- It contains 10% N, 10% Zn and 5% S.
 Zinc-glass frits/Zinc frits
- Glass and Zn compounds togetherly fused. After
freczing it is shattered. The small pieces, thus obtaincd,
arc called Zn frits.
- Its solubility is less than the solubility of Zn
compounds. Thus, leaching loss of Zn reduces.
- Its Zn content varies widely (10-30% Zn)
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12.  Zinc chelates
- They are organic compounds. They bond with Zn.
Several Zn chelates are available, such as
- Zn EDTA1 (12% Zn.)free flowing, crystalline or
powder.
- Zn HEDTA2 (9% Zn)
- Zn NTA3 (13% Zn)
- Zn chelates or chelated Zn can be foliar sprayed or soil
applied.
- When added to soil the mobility of chelated Zn is not
restricted. Thus, plants can absorb more Zn.
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13. MANGANESE FERTILIZERS
 Four kinds of manganese fertilizers are available.
1. Manganese-glass frits.
2. Inorganic mangancse fertilizers.
3. Natural organic complexes.
4. Synthetic manganese chelates.
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14.  1.Manganese sulphate [MnSO4.4H20]
- It is crystalline, soluble in water and free flowing.
- It contains approximately 23-28 % Mn. [depending on
hydration] , 14-15 % S .
- Among all Mn fertilizers its use is wide
- It can be soil applied or aqueous solution can be foliar
sprayed
 2.Chelated manganese [MnEDTA]
- It is a chelate of Mn and EDTA.
- It contains 5-12% Mn,
- Its aqueous solution can be sprayed over the foliagc.
- Its soil application is normally not recommended since
Fe and Ca in soils replace Mn in chelates. The replaccd
Mn is converted to unavailable form. Thus, Mn deficiency
may result.
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15.  3. Manganese oxide [MnO]
- It is obtaincd in the form of powder.
- It contains about 41-68% Mn.
- It is slightly soluble in water.
- It can be applied to soil or its aqueous solution can
be spraycd over the foliage.
- Manganese dioxide (MnO2) is also available. It
contains 63% Mn.
 4.Manganese chloride [MnCl2]
- It is crystalline and highly hygroscopic.
- It contains about 17% Mn.
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16.  5.Manganese frits
- Glass and Mn compounds are togetherly fused. After
freezing it is shattered. The small pieces thus obtaincd
are called Mn frits.
- Its solubility is less than the solubility of Mn
compounds. Thus, lcaching loss of Mn reduces if the
frits arc applicd to coarse-textured soils (e.g. sandy
loam soils) in arcas of high rainfall.
- Their Mn content varies widely from 10 to 35%.
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17.  For soils having pH above 6.5, band placement of Mn
fertilizers is more effective than broadcast application.
 For broadcasting the higher rates are needed while for
banding relatively lower rates arc sufficient. Usually, band
rates are one-half the broadcast rates .
 Banding Mn fertilizers mixed with acidic fertilizers, such as
ammonium sulphate is more effective in correcting Mn
deficiency.
 Soil application of Mn chelates (viz. Mn EDTA, Mn DTPA)
is not effective. Their foliar application is effective.
 For correcting Mn deficiency foliar application and band
placement of Mn fertilizers are more effective than
broadcast application
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18. COPPER FERTILIZERS
 The following kinds of copper fertilizers are
available,
1.Copper Sulphate
2.Copper chelate or Chelated copper
3. Copper ammonium phosphate
4.Copper nitrate
5.Copper oxide
6. Mixture of Copper Sulphate and Copper
hydroxide / Basic Copper Sulphate
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19.  1.Copper Sulphate (CuSO4.5H2O)
- It is also known as blue-vitriol.
- It is blue, crystalline, hygroscopic and soluble in water.
- It contains 24% Cu (minimum content in India) and
12.8% sulphur .
- It can be used as Foliar spray.
- It is widely used.
 2.Copper sulphate CuSO4.H20 (Copper sulphate
monohydrate).
- It contains 35% Cu.
- As it is hygroscopic it cann't be blended
well with NPK fertilizers. Morcover, it may react with
phosphates in phosphatic fertilizers to yield
insoluble Cu compounds and thus render Cu
unavailable.
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20.  3.Copper chelate or Chelated copper
- Copper is chelated with EDTA or HEDTA.
- CuEDTA contains 13% Cu.
- Cu HEDTA contains 9 % Cu.
- Both are soluble in water
- They can be used as foliar spray and
soil application.
- Their use is costly.
 4. Copper ammonium phosphate [Cu(NH4) PO4.H2O]
- It contains 32% Cu.
- It is slightly soluble in water.
- If added to soil the plants can take Cu very slightly for
long period.
- Its water suspension can be sprayed over the foliage.
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21.  5.Copper nitrate [Cu(NO3)2.3H20]
- It is blue, crystalline, hygroscopic and readily soluble in
water and contains 26% Cu.
 6.Copper oxide [CuO]
- It is black and insoluble in water.
- It contains 75% Cu.
- Its efficiency depends on its particle size. As it is
insoluble it may not cure the Cu deficiency in the year of
application. But its residual effect in the subsequent years
may cure
.
 7. Mixture of Copper Sulphate and Copper hydroxide / Basic
Copper Sulphate [CuSO4. x Cu(OH)2]
- It is alkaline.
- It contains 12-50% Cu. 21

22. BORON IN FERTILIZERS
 The following kinds of boron fertilizers are available
1. Borax
2.Sodium tetraborate
3. Solubor
4.Colemanite
5.Boric acid
6.Borosilicate glass/Boron frits/Fritted glass
7.Boronated (or borated) single superphosphate
8.Sodium pentaborate
9.Sodium tetraborate
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23.  1. Borax [Na2B407.10H20]
- It is sodium tetraborate decahydrate.
- It is white and soluble in water.
- It contains minimum 10.5% B.
- Its use is widespread.
- It is generally used for soil application though its
solution can be sprayed over the foliage.
- It rcadily leaches in sandy soils in high rainfall areas.
 2.Sodium tetraborate. Na2B4O7.5H20
- It contains about 14-15% B 23

24.  3. Solubor [Na2B407.5H20 +Na2B10O16.10H20]
- It is the mixture of sodium tetraborate and sodium
pentaborate.
- It is partially dehydrated borax.
- It is highly soluble in water. It dissolves faster than
borax. Thus, its use gets preference over borax.
- It is used for both soil and foliar applications as
foliar spray ,liquid fertilizer , slurry or suspension fertilizer
- It contains minimum 19% B.
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25.  4.Colemanite [Ca2BO11.5H20]
- It is a natural deposit of calcium borate.
- It is less soluble than borax. Thus, it is suitable for
application to coarse-textured soils that are subjected to
leaching loss .
- It contains 10-16% B.
 5.Boric acid [H3BO3]
- It is white and crystalline.
- It is soluble in warm water
- It contains about 17% B.
- It can be used as foliar spray , liquid fertilizer or
slurry fertilizer
- lts use is limited.
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26.  6.Borosilicate glass/Boron frits/Fritted glass
- Borax is fused with silicate glass and shattered .Thus,
frits are obtained.
- In frits the solubility of borax decreases. The frits steadily
release B (boron) to soils. Thus, this fertilizer is effective for
long duration crops viz. apple.
- The leaching loss of B from boron frits decreases in soils
particularly in light soils (e.g. sandy soils) that receive high
precipitation (rain water).
- It is suitable for application to sandy soils in humid
regions where rainfall is high.
- It contains 3-6% B.
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27.  7.Boronated (or borated) single superphosphate
- Boron salt is mixed with single superphosphate
- It contains maximum 0.18% B.
- It s a powder
Boronated gypsum, boronated calcium carbonate,
boronated calcum nitrate are also available.
 8.Sodium pentaborate [Na2B10O16.10H20]
- It contains 18% B
 9.Sodium tetraborate [Na2B407.5H20]
- It contains 15% B.
- Another tetraborate is also available, Na2B407 (21%B)
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28. MOLYBDENUM FERTILIZERS
 The following kinds of Molybdenum fertilizers are
available
1.Ammonium molybdate
2.Sodium molybdate
3.Molybdenum trioxide
4.Molybdenum-glass frits
5.Molybdic acid
6.Calcium molybdate
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29.  1.Ammonium molybdate [(NH4)6Mo7024.4H20]
- It is white and soluble in water.
- Mo content is minimum 52% .
- Mixed with NPK fertilizers it can be applied to soils.
- Its aqueous solution can be sprayed over the foliage or
applied to soil.
- Before seeding the seeds may be mixed (or coated) with
this fertilizer and a sticking agent or soaked with its
aqueous solution (seed treatment).
 NOTE : Very small amount of Mo is needed by plants.
Among all "essential elements“ Mo is the only element
which is needed in smallest amount. Thus, Mo is called
nano nutrient or ultra micronutrient.
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30.  2.Sodium molybdate [Na2MoO4.2H20]
- It is water-soluble.
- It contains about 39% Mo
- It is also used as seed treatment
- Foliar spraying can be done.
 3.Molybdenum trioxide [MoO3]
- It contains about 66% Mo.
- It is slightly soluble in water.
- Its aqueous solution can be sprayed over the foliage
(Foliar spray)
- Mixed with NPK fertilizers it can be applied to soils.
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31.  4.Molybdenum-glass frits
- Its solubility is less than the solubility of Mo compounds.
Thus, leaching loss of Mo reduccs if the frits are applied to
coarse textured soils in high rainfall areas
- Mo content varics widcly from 1 to 30%.
 5.Molybdic acid [H2MoO4.H20]
- It contains 53% Mo.
 6.Calcium molybdate [CaMoO4]
- It contains 48% Mo.
- It is insoluble in water
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32. THANK YOU..
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