Fertilizers

Fertilizers:

Fertilizers are the organic or inorganic materials of natural or synthetic origin which are added to the soil to supply certain elements essential to the growth of plants.  

AMENDMENTS:

are the substances other than Manures and fertilizers which are added to soil for the improvement of their condition

Amendments are also termed as ameliorants , improves or soil conditioners e.g gypsum and lime though they supply nutrients but the main objective of applying them is for correcting the soil condition. 

CLASSIFICATION OF FERTILIZERS:

A) Straight fertilizers:

Such fertilizers has declarable content of only one major nutrient 

e.g. urea , ammonium sulphate

B) Binary fertilizer:

Contains two major nutrients 

e.g. Potassium Nitrate

C) Ternary fertilizer:

Contains three major nutrients

e.g. Ammonium potassium phosphate

D) Compound/ Complex fertilizer 

Such fertilizer has a declarable content of at least two of the major nutrients obtained chemically and generally granular in form 

e.g. Nitro-phosphate , Diammonium phosphate (DAP) 

E) Mixed Fertilizer : Individual or straight fert materials are blended together physically to permit application in the field in one operation. Such fertilizers supply two or three major nutrients in a definite proportion or grade 

e.g. Nitro-phosphate with potash 15:15:15 of NPK

F) Complete Fertilizer:

Having all the three primary major nutrients viz. N, P, K 

G) Incomplete fertilizer : 

Containing any two primary nutrients

H) low analysis fertilizers : having less than 25% of the primary nutrients

e.g. SSP (16% of P2O5) 

I) High -analysis fertilizer : having more than 25% of the total primary nutrient content e.g. urea , anhydrous ammonia (82.2% N) 

• Fertilizer grade: refers to the guaranteed analysis of its plant nutrients.. 

• Fertilizer Ratio: 

Refers to the relative percentage of N, P2O5 and K2O i. e. 1:4:4 if Fertilizer grade is 6:24:24

• MATERIALS USED IN MANUFACTURING OF FERTILIZERS:

(MIXED):

1) Suppliers of plant nutrient : 

Straight fertilizers are used for this purpose

2)Conditioners:

To check absorbing moisture and making one , conditioners like straw , groundnut husk , paddy husk , peat soil  are used 

3)Neutraliser of acidity or basicity :

Dolomitic limestone is used to reduce residual acidity

4) Filler material or make weight material: 

Sand , soil , earth , coal ash , charcoal such waste materials are added

• Precautions in mixing fertilizers:

1) Hygroscopic fertilizers should not be mixed because they form cakes after mixing 

Hygroscopic fertilizers are

a) NH4NO3 ( Amm. Nitrate ) 

b) Urea( CO(NH2)2

c) Ammonium sulphate (NH4)2SO4

d) Calcium Ammonium nitrate (CAN) 

Most Hygroscopic fert.is Ammonium nitrate and urea stands second 

2) All water soluble phosphatic fertilizers like super phosphate should not be mixed with those fertilizer that contain free lime because it will convert the soluble phosphate into insoluble form

3) Slightly acidic fertilizer containing chloride may damage the gunny bags and drilling equipments 

Acidity and basicity of fertilizer:

✓ Equivalent acidity:

The amount of CaCO3 required to neutralise the acid residue caused by application of acidic fertilizers in the soil 

e.g 100 kg (NH4)2SO4 produces acidity which needs 110 kg of CaCO3 to neutralise it. 

Equivalent basicity : Residual  basicity caused by application of basic fertilizers, expressed in terms of CaCO3 equivalent of basic residue left by a in fertilizer material

Characteristics of:

Nitrate Fertilizer : 

Highly mobile in soil , suitable for top dressing, highly soluable and subjected to leaching and denitrification in water logged soils , more suitable for dry soils

Ammonical Fertilizer: Readily soluable in water , suitable for water logged fields , acidic in nature 

Amide Fertilizer:

Organic fertilizer, first converted into ammonical and then to nitrate form 

Urea is acidic but CACN is basic 

Nitrate ammonical group 

NO3 nitrogen readily available to plants for rapid growth and NH4+ notrogen at later stage 

1) Sodium Nitrate: 

16%  N , Chilean nitrate , pioneer nitrogenous fertilizer use

2) Ammonium Sulphate:

20.6% N , 24% S

3) Ammonium nitrate - 33-35% N , highly Hygroscopic and not fit for storage 

4) Amm. Sulphate Nitrate: 

26% N, 15% S

5) Calcium Ammonium Nitrate(CAN) :

Kisan khad  25-28% N almost neutral in nature,, most suitable for vegetables

6) Ammonium Chloride: 26% N extensively used in paddy in Japan . 

7) Urea: 

Mostly used in India , 46% N 

8) Cyanamide: 20.6% N

9) Aqueous ammonia : 80% N used as fertigation i.e. in Irrigation water

PHOSPGATIC FERTILIZERS:

3 types

A) Water Soluble:

Ca(H2PO4)2 such water soluble phosphatic fertilizers are used for quick start and short duration like wheat , for neutral and alkaline soils

e.g.

1) Super Phosphate is of three types 

1) Single super phosphate (SSP)

16-20% P2O5

2) Double Super Phosphate (DAP):

32% P2O5

3) Triple Super Phosphate (TSP)46-48% P2O5

2) Monoammonium phosphate( MAP) : 12% N and 48% P2O5

3) Diammonium Phosphate (DAP) 16-48-0

B) Citrate soluble ( but water insoluble)

1)  Dicalcium phosphate : 33-40% P2O5 

2) Basic slag: 14-18% P2O5

C) Citrate and water Insoluble a: Tricalcium Phosphate  used in strongly acid soils and suitable for plantation crops

e.g. 

1) Rock Phosphate - 20-30 % P2O5

2) Raw Bone meal - 3-4% N + 20-25 % P2O5

3) Steamed bone meal - 1-2% N+ 20-30 % P2O5 

Single Super Phosphate (SSP):

SSP contains 12% S + 16% P2O5+ 18-21% Ca 

Among phosphatic fertilizers, SSP is widely used in India 

It is prepared by treating Rock Phosphate with equal amount of sulphuric acid 

SSP is suitable for all the crops and different soils

According to standard, SSP must contain

Moisture content by wt. : 12% ( Maximum) 

Potassic fertilizers: 

1) Muriate of potash : (MOP)

KCI , 60% K2O

2) Potassium Sulphate or sulphate of potash (SOP): 48-52 % K2O and 17-18 % S . 

Suitable for light soil and for those crops for which MOP is unsuitable

3) Nitrate of Potash (NOP) /Potassium Nitrate (KNO3)

13% N , 44% K2O 

Excellent source of K and N , mainly used for fruit trees and crops such as tobacco and vegetables

✍️Agricos

 Vaishnavi Nimkar 🌾🌱