The document presents methods to enhance fertilizer use efficiency (FUE), emphasizing the importance of choosing the right fertilizers based on soil and climatic factors. It discusses various agronomic, chemical, and physiological strategies aimed at increasing FUE, including application timing, placement techniques, and the use of organic materials. The conclusion highlights a holistic approach through the '4 Rs' of FUE: right source, rate, time, and place.

1. A PRESENTATION ON
AGRONOMIC,CHEMICAL AND
PHYSIOLOGICAL METHODS OF
INCREASING FERTILZER USE
EFFICIENCY(FUE)
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Prepared by:
Sunita Meher
M.Sc.(Ag)previous(Dept.of Agronomy)
CoA,IGKV,Raipur(C.G)

2. INTRODUCTION
FUE(Fertilizer Use Efficiency):
It may be defined as yield per unit fertilizer input or it may be fresh weight or
product yield per unit content of nutrient.
Our aim is to get maximum economic yield with minimum inputs.Higher
efficiency from fertilizers the following aspects must be considered.
Correct choice of fertilizers from a wide selection of fertilizers having
different chemical and physical characteristics.
The fertilizer recommendation based on nutrient supplying power of soils
and by specific soil, plant and climatic factors.
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3. Nutrient Efficiency Cause of low efficiency
Nitrogen 30-50 %
Immobilization,
volatilization, denitrification,
Leaching
Phosphorus 15-20%
Fixation in soils Al – P, Fe – P,
Ca – P
Potassium 70-80% Fixation in clay - lattices
Sulphur 8-10%
Immobilization, Leaching
with water
Micro nutrients (Zn, Fe, Cu,
Mn, B)
1-2% Fixation in soils
Nutrient use efficiency of different nutrients
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4. •Leaching(NO3)
•Gaseous Losses(NH3,N2O,N2)
•Immobilization by chemical precipitation, adsorption on exchange
complex and microbial cells.
•Chemical reactions between various components in fertilizers during
mixing, before application to soil.
•Physical properties of soil
•Chemical properties of soil
•Fertilizer characteristics.
Factors affecting FUE
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5. Methods of Increasing Fertiliser Use Efficiency
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Following methods which can be adopted to increase FUE:
Agronomic methods
Chemical methods
Physiological methods

6. 1.Agronomic methods
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i. Application of fertilisers at right time with required quantity
The phosphates in general are more efficient when the entire dose applied as
basal dressing, potash entire quantity as basal dressing or part as basal and rest in
split doses depending on the soil texture and the nitrogen in 2-3 (or 4) split doses.
Example
In Ground nut,
20 kg N /ha – entire dose as basal is recommended for rainfed G.nut
30 Kg N/ha – in 2 equal splits at seeding & 30 DAS – irrigated crop.
An initial boost as starter dose of 10 kg/ha is necessary for rainfed groundnut.
Depending on the number of nodules, another 10 kg/ha at 30 DAS can be top
dressed depending on the rainfall.
In Sugarcane,
· Potassium application normally done along with N application because of
better utilization of N, in the presence of K. therefore K is applied at 45, 90 DAS.

7. Solid Fertiliser
• Deep placement
Placement of ammoniacal nitrogenous fertilizers in the reduction zone of soil
particularly in paddy fields.
• Localized placement
It refers to the application of fertilizers into the soil close to the seed or plant in
order to supply the nutrients in adequate amounts to the roots of growing plants.
a) Drilling
• By means of a seed-cum-fertilizer drill.
• Suitable for the application of phosphatic and potassic fertilizers in cereal crops
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ii)Application methods

8. b) Side dressing
Between the rows and around the plants.
Placement of nitrogenous fertilizers by hand in between the rows of crops
e.g maize, sugarcane, cotton etc.
Around the trees like mango, apple, grapes, papaya etc.
c) Band placement
i)Hill placement
e.g In orchards
ii) Row placement
In crops like sugarcane, potato, maize, cereals etc. i.e close growing crop
• Pellet application
Placement of nitrogenous fertilizer in the form of pellets(fertilizer :soil is of 1:10)
2.5 to 5 cm deep between the rows of the paddy crop.
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9. Liquid fertiliser
a) Starter solutions
• It refers to the application of solution of N, P2O5 and K2O in the ratio of 1:2:1 and
1:1:2 to young plants at the time of transplanting, particularly for vegetables
b) Foliar application.
• Micro nutrients and also urea @1- 2.5% & potassium @2.5%in sugarcane.
c) Application through irrigation water (Fertigation)
• Generally nitrogenous fertilizers
d) Injection into soil
• Anhydrous ammonia must be placed in narrow furrows at a depth of 12-15 cm and
covered immediately to prevent loss of ammonia.
e) Aerial application.
• Particularly in hilly areas, in forest lands, in grass lands or in sugarcane fields etc.
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10. Other techniques:
• Strip‐till systems
A narrow strip (about 1/3 of the surface) is tilled and nutrients are concentrated in
a band below the surface, maintaining a predominantly untilled surface residue
environment to help reduce erosion and conserve soil moisture.
• Variable-rate application
• Optimum planting or sowing time, plant spacing
• Application oforganic manures having high C:N ratio with adequate amount of
nitrogenous fertilizers.
• Crop rotation with leguminous crops
• Avoid excessive irrigation
• Avoid weeds, pest and diseases infestation.
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11. 2.Chemical methods
Synthetic or chemical fertilizers should be of good quality and right source for crops.
Examples:
• Oilseed- Generally Sulphate fertilizers like elemental sulphur @25Kg/ha,ZnSO4
@25Kg/ha,Borax @1-2% application must be done.
• In tobacco plant avoid using of fertilizers containing chlorine for preventing from
schorching effect.
• In tea plantation use of (NH)2SO4 is best.
• In Paddy, Ammonium and urea fertilizer are more efficient for paddy under
different Indian conditions than nitrate fertilizers.
• Water soluble phosphorus materials - for short duration crops and neutral to
alkaline is reaction.
• Also interaction noticed among crops and fertilizers.
paddy performs better when ammonium sulphate is applied as N carrier and tobacco
when potassium sulphate is applied as potassium carrier.
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12. Fertilizer forms Example
Coated with inert
material
Urea coated with polymer, lac, gypsum, sulphur, and
rock phosphate
Enlargement of
the granule
Urea supergranule, granular urea
Limited
solubility forms
of urea
Urea form, Oxmide, Urea-Z
Coated with
urease inhibitors
Hydroquinone, phenyl phosphorodiamidate (PPD)
Coated with
nitrification
inhibitors
Nitrapyrin, AM (acetylene, 2-amino-4chloro-6-methyl-
peyrimidine), DCD (dicyandiamide), ATC (4-amino
1,2,4-triazole),encapsulated Ca-carbide, neem cake,
karanj cake, DMPP (3-4-dimethylpyrazole phosphate)
Product strategies to increase FUE
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13. Organic substances, e.g. crop residues, manure, slurry, composts, heat-dried or
sundried
Sewage sludge (biosolids), etc.;
 organic or organic-mineral fertilizers, e.g. meat and bone meal, hoof and horn
meal,
Rapeseed meal, treated leather meal, mahua seedcake etc.;
Inorganic compounds, metal-ammonium phosphates
(struvites, e.g. magnesium)
ammonium phosphates (MgNH4PO4)), and partially acidulated phosphate
rock(PAPR).
Others slow released fertilizer
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14. Fertiliser Mixtures
• Urea can be mixed with all fertilizers.
• Other fertilizers can be mixed just before use. But the efficiency of the following
fertilizers will be lowered if mixed with the fertilizer or amendment noted against
them.
• Ammonium sulphate - Basic slag
• Ammonium sulphate - Calcium carbonate
• Super phosphate - Basic slag
• Ammonium phosphate - Basic slag
• Ammonium phosphate - Calcium carbonate
• Super phosphate - Calcium carbonate
•
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15. 3.Physiological methods
• For sandy soil, applying more time but smaller amount at each. For loamy soil,
mainly base fertilizer, base fertilizer and top dressing combined.
• For argillaceous soil, mainly apply base fertilizer and early top dressing.
• Ammonium and potassium ions in fertilizer may be immobilized by strong
adsorption by 2:1 type clay minerals.
Practical means of reducing the fixation and increasing the efficiency of fertilizer under
these conditions are
 timely application of fertilizers
 proper placement of fertilizer
 application of nitrate fertilizers
 application of relatively insoluble potassium fertilizers and
 increasing the dosages of fertilizers.
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16. • In acid soils- Insoluble phosphatic fertilizer like rock phosphates
• A thorough mixing of the phosphorus with soil.
• In calcareous soils -water soluble phosphorus are relatively more efficient than
water insoluble P like rock phosphate.
• Inorganic water soluble N fertilizers with high C:N ratio organic materials.
• In fine textured soil, or in compact soils, Higher doses is to be applied.
• Soil temperature affects the fertilizers efficiency by changing solubility of
fertilizers
Nitrogen:
• Below 13c the uptake of N from NH4 or NO3 fertilizers is almost nil.
Maximum uptake of N by plants from NO3 and NH4 fertilizers is observed in the
range of 19 - 24c.
Phosphorus: Increases FUE in the range 10-35c temperature.
Potassium: The effect of soil temperature in range 24 – 28c on FUE.
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17. • Foliar nutrition of urea @1- 2.5% & potassium @2.5% under moisture stress is
useful to improve yield and quality in Sugarcane.
• In strongly acidic and alkali soils apply suitable amendments for higher PUE.
• Physiologically alkaline fertilizers like calcium cyanamide, Ammonium nitrate
basic slag -acid soils and
physiologically acid fertilizers like ammonium sulphate etc. - alkaline soils.
• Lesser fertilizer requirement of Deep rooted crops shallow one.
• More ‘N’ (1/4 extra dose) should be applied as basal dressing for aged seedlings
unlike Dapog system.
• If possible adopting HYVs of crops.
• Curing of urea by mixing the urea with 5-10 parts of soil thoroughly and keeping
the mixture for overnight.
• NUE can be increased by mixing the fertilizer with crushed neem seed (5:1 parts)
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18. CONCLUSION
• In a holistic approach FUE can be increased by following 4Rs:
1.Right source
• Provide plant-available forms, and a balanced supply of all essential nutrients. Take
advantage of various formulations that offer improved efficiency and reduce
environmental consequences.
2.Right rate
• Ensure an adequate supply of all essential nutrients to meet plant demand.
3.Right time
• Manage nutrient applications to match the interactions of crop uptake,
• soil supply, environmental risks, and field operation logistics.
4.Right place
• Consider root-soil dynamics and nutrient movement, and manage spatial
variability within the field to meet site-specific crop needs and minimize potential
losses from the field.
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