Nutrient Management

Principles of Nutrient Management Estimation of Fertilizer Requirements Major and Micro Nutrients Phosphorus Potassium Zinc Iron Soluble Fertilizers Organic Manures Biofertilizers

Principles of Nutrient Management

    To Provide nutrients to crop plants

    In required quantities

    • Climate (Tropical/temperate)
    • Type of crop (Legume/non legume)
    • Season (Kharif/rabi/summer)

    in available forms

    • Readily available
    • Slowly available
    • Fixed in the soil

    at right time

    • Critical phase for nutrient
    • Type of fertilizer/manure

    by right method

    • Mobility of nutrient
    • Type of nutrient (Macro/micro, soil/plant)
    • Loss of nutrient (Volatilization/leaching)  


Estimation of Fertilizer Requirements

Nutrient requirement depends on

  • Target yield and soil nutrient supply
  • Type of fertilizer and recovery
  • Timing (which is dependent on the maturity of variety)

To estimate fertilizer requirements we need to know

  • Target yield
  • Crop yield with no fertilizer
  • Fertilizer recovery


Target yield: 4.5 tonnes per hectare

Yield without fertilizer: 1.5 tonnes per hectare

Yield to come from the fertilizer: 4.5   1.5 = 3 tonnes per hectare

Approximate fertilizer needed per tonne of crop

N = 15 - 20 kg N/ha, P = 2.5   3 kg P/ha , K = 15   20 kg K/ha

Thus to get additional yield of 3 tonnes grain per/ha the crop require an additional

3 (15 - 20) = 45   60 kg N/ha

3 (2.5   3.0) = 7.5   9 kg P/ha

3 (15   20 ) = 45   60 kg K/ha

Typically N is the primary limitation and the other nutrients may or may not be needed.

N recovery is typically of the order of 50% thus to supply 45-60 kg N per ha to the crop, it will be necessary to apply between 90-120 kg N per ha.

If slow release of urea, super granules applied by deep placement   increase the recovery of N and thus the quantity of fertilizer can be reduced.

If 1/3 N as basal , 1/3 at mid tillering and 1/3 at P.I, the recovery of N is of the order of 35%, 45% and 65% of applied N respectively.

Therefore 1/3 x 30% + 1/3 x 45% + 1/3 x 65% = 48% total recovery.

If there is no basal, 1/3 delayed, 2/3 at PI, then the recovery in the order of 40% and 60% of applied N respectively.

Therefore 1/3 x 40% + 2/3 x 60% = 53% total recovery.


Major and Micro Nutrients



  • One of the three major nutrients.
  • Most limiting nutrient.
  • Highly soluble and highly mobile.
  • Rapid transformation into leachable forms.
  • Losses may be as a gas (volatilization) when nitrate is exposed to anaerobic condition and leaching.

Role of Nitrogen in Plant System

  • Green color of plant (photosynthesis).
  • Rapid vegetative growth (height , tillering , branching).
  • Increased leaf size (more leaf area and high radiation use efficiency) 
  • Increased protein content of grain (% Nitrogen x 6.25 = % Protein)

Deficiency Symptoms

  • Stunted growth (less dry matter à less utilisation of inputs) 
  • Yellowing of leaves (Less photosynthetic efficiency)  
  • Reduced grain yield (Due to less source and sink development)

Injury Due To Excess Nitrogen - Fertilizer

  • Leads other nutritional problems
  • Increased pest and disease incidence
  • Dark green Vegetation
  • Lodging of crop due to excess growth

N- Management In Chillies

  • Season x Utilisation of Nitrogen Rainy season (Kharif) - Smaller

Nitrogen requirement Reasons

  • Less sun shine Less yield potential (Lower source, sink development) Dry seasons(Rabi / summer): Higher Nitrogen -Requirement Reasons: More sunshine Greater yield potential (More source, sink development) Critical Stages of Nitrogen: Sufficient Nitrogen at branching (adequate branching will increase the fruiting points and yield) Sufficient Nitrogen at flowering (to ensure adequate sink) Sufficient Nitrogen at fruit development (to increase the fruit size) Nitrogen - Management: Rainfed chilli:   Apply 24 Kg Nitrogen, 16 Kg P2O5 and 20 kg K2O per acre at the time of last ploughing.
  • As per rainfall distribution apply 10-12 Kg Nitrogen/ac atleast twice during crop period.
  • Irrigated Chilli:   Apply 24 Kg Nitrogen, 24 Kg P2O5 and 12Kg K2O per acre at the time of last ploughing.
  • At 45,60 and 75 days after sowing apply @ 12 Kg Nitrogen and 4 kg K2O /acre.
  • Later at 20 days interval apply twice @ 12 Kg Nitrogen/acre.
  • At the time of spraying of any insecticide to the crop spray 1% urea along with insecticide (except with Carbaryl urea can be mixed and sprayed with all pesticides and fungicides.)
  • Use more splits - for long duration varieties - for the crop meant for green chilli - for light textured soils
  • Avoid large basal Nitrogen application (Limited uptake since growth is slow during first three weeks after transplantation.)
  • Incorporation basal Nitrogen into soil before planting / sowing.

Fertilizer recommendations for chilli under rainfed and irrigated conditions

Situation Time of application
Nitrogen (kg/ac)
P2O5 (kg/ac)
K2O (kg/ac)
Rainfed Basal
  1st top dressing
  2nd top dressing
Irrigated Basal
  1 st top dressing (45 DAT)
  2 nd top dressing (60 DAT)
  3 rd top dressing (75 DAT)
  4th top dressing (95 DAT)
  5th top dressing (115 DAT)

Steps for increasing Nitrogen -use efficiency:

  • Apply right quantity at right time by right method.
  • Root zone placement of Nitrogen fertilizers.
  • Balanced fertilization.
  • Supplementary use of organic manure's and bio fertilizers.
  • Correction of micro nutrient deficiency (especially zinc and Fe).
  • Maintain adequate plant population.
  • Proper water management practices.
  • Effective weed control.

Sources of Nitrogen Organic Sources

Nitrogen (N) (per cent)
Farm Yard Manure
0.5   1.5
Compost (Urban)
1.0   2.0
Compost (Rural)
0.4   0.8
Green Manure's
0.5   0.7
Non-Edible Cakes  
Castor cake
5.5   5.8
Cotton seedcake (undecorticated)
3.9   4.0
Mahua cake
2.5   2.6
Karanj cake
3.9   4.0
Neem cake
5.2   5.3
Safflower cake (undecorticated)
4.8   4.9

The inorganic fertilizers

Name of the fertilizer N % Remarks
A) Urea 44.0   46.0
  • Urea, Ammonium sulphate nitrate, Calciumammonium nitrate and Calcium nitrate are generally used. Among which cost for 1 kg nitrogen is cheaper in urea.
  • Ammonium sulphate should not be mixed with seed as germination of seed affected.
  • Ammonium sulphate nitrate should not be mixed with lime and should not be applied along with the seed.
  • Urea is an ideal fertilizer for foliar application also its contact with seed should be avoided.
B) Ammonium Sulphate 19.9   20.0
C) Ammonium Sulphate Calcium Nitrate 26.0
D) Ammonium Nitrate 25.0
E) Ammonium Chloride 25.0
F) Calcium Nitrate 13.0   15.0
G) Sodium Nitrate 16.0
H) Calcium Cyanamid 21.0
I) Anhydrous Ammonium 82.0
J) AmmoniumNitrate 32.0   35.0

Compound Fertilizers
Form N P2O5 K2O Companies
A) Diammonium phosphate 18 46 0 GFCL, SPIC, PPL
B) Urea Ammonium Phosphate (Gromor) 28 20 28 20 0 CFL, FACT, ZACL FACT
C) Co(NH2)2(NH4) Hpo4 24 24 0 -
NPK 10 26 26 IFFCO
  17 17 17 MFL
  15 15 15 RCF
  19 19 19 ZACL
  14 35 14 CFL, ZACL
        Complex fertilizers are costlier than the straight fertilizers.




  • One of the three major nutrients.
  • Immobile
  • Limiting nutrient - Limited availability
  • Negligible / No loss
  • Most of the Phosphorus fixed in soil.

Role of Phosphorus in Plant System

  • Stimulates growth and development of roots
  • More encourage to plant
  • More uptake of nutrients.
  • Promotes early flowering and ripening(Late planted crop comes to harvest in time)
  • Encourage branching
  • Encounters adverse conditions in early stages of crop growth.

Deficiency Symptoms

  • Leaves turn to red from tip to margins.
  • Stunted growth.
  • Poor branching.
  • Poor root growth.
  • Delayed flowering and maturity.

Injury Due To Excess Phosphorus Application

  • Fixed in soil - not available to plants
  • Leads Zinc deficiency.

Phosphorus - Management In Chilli

  • Phosphorus fertilizer requirement is smaller in rainy season (less sunshine smaller potential yield), larger in dry season (more sunshine, greater potential yield).
  • Phosphorus -Fertilizer should be applied before transplanting, since P2O5 is required in the initial stages of crop for root and branch development.
  • Phosphorus is highly immobile, hence applied nearer to root zone before transplantation.

Sources Of Phosphorus

A) Organic Manures (Inorganic Fertilisers)

Phosphatic fertilizers
  • Super phosphate (Single)
16.0   20.0 Rock phosphate, Basic slag, Bone meal are insoluble phosphates and they are not usually recommended.
  • Super Phosphate (Double)
30.0   35.0  
  • Super Phosphate (Triple)
45.0   50.0  
  • Basic slag
3.0   8.0  
  • Mussori
23.0   24.0  
  • Purulia

Compound Fertilizers
N %
P %
K %
Resource Companies
Nitrogen %
Potassium %
Resource Companies
A) Diammonium Phosphate
B) Urea Ammonium Phosphate (Gromor)
28 20
28 20
0 0
C) Co (NH2)2 (NH4) Hpo4
D) NPK Complex Fertilizers
Complex fertilizers are costlier than the straight fertilizers.



Sources Of Potassium

A) Organic Manures

Potash (K2O) (per cent)
Farm Yard Manure
0.4   0.8
Compost (Urban)
Compost (Rural)
0.3   0.6
Green Manures
0.1   0.2
Non-Edible Cakes  
Castor cake
1.8   1.9
Cotton seedcake (undecorticated)
1.8   1.9
Mahua cake
0.8   0.9
Karanj cake
0.9   1.0
Neem cake
1.0   1.0
Safflower cake (undecorticated)
1.4   1.5

B) Inorganic Fertilizers

Potassic fertilizers
Muriate of Potash(KCL)
50.0   60.0
The potassium chloride and potassium sulphate are not easily leached out.
Potassium sulphate
48.0   52.0
Potassium phosphate
30.0   50.0

Complex fertilizers

NPK Complex Fertilizers
Complex fertilizers are costlier than the straight fertilizers.




  • Zinc importance in plant nutrition is recognised after the introduction of high yielding varieties.
  • Zinc deficiency caused by intensive cropping.
  • To get full benefits of Nitrogen, Phosphorus and Potassium fertilizers zinc deficiency should be prevented.

Role In Plant System

  • Producing several enzymes.
  • Responsible for chlorophyll formation.
  • Deficiency reduce photosynthetic activity.
  • Playing a role in Nitrogen - metabolism.
  • Regulate Auxin (Hormone) production.
  • Promotes Nucleic acid production for protein synthesis.

Deficiency Symptoms

  • Discolouration of older leaves starting from 2-3 weeks after planting.
  • Uneven crop stand.
  • Under acute conditions margins of older leaves dry up.
  • Fresh leaves smaller in size.
  • No uniform maturity of crop.

Injury Due To Excess Fertilizer

  • Excess zinc cause deficiency of Iron.

Management Of Zinc For Chillies

  • 20 kg of Zinc Sulphate /ac to soil in the final ploughing. Once in 2-3 crops in single cropped areas.
  • Give a gap of 4-5 days between application of phosphorus and Zinc since Zinc has Antagonistic effect with phosphorus.
  • Zinc deficiency on standing crop can be corrected by spraying 0.2% zinc Sulphate solution (2g/lt of water) about 200 liters of spray solution is required to cover one acre.
  • Spraying should be repeated 2 times at an interval of 5-10 days.


  • Zinc sulphate - Zn So4 7H2O (21%Zn)
  • Zn So4 H2O (33% Zn)
  • Chelated Zinc (12% Zn)




  • Deficiency of Iron also seen where excess calcium applied.
  • In high pH soils Iron deficiency is common.
  • Excess application of Phosphorus, Manganese, Copper, Zinc leads to Iron deficiency.
  • High temperatures cause some times Iron deficiency.

Role In Plant System

  • Acts as a catalyst in chlorophyll formation.
  • Necessary for almost all metabolisms of plant directly or indirectly.

Deficiency Symptoms

  • Intervienal chlorosis in stripes or streaks in young leaves.
  • Drying starts inwards from tips and margins of leaves.
  • Leaves become white in color and dried under sever conditions followed by shedding of leaves.

Injured Due To Excess Fertilizer

  • Excess iron reduced the availability of Manganese.
  • Create imbalance in nutrient supply.
  • Availability of excess iron is very common in acid soils
  • acidic sulphur rich soils and low potash soils under these conditions addition of lime, FYM , Phosphorus and Potassium is necessary.

Management Of Nutrient Iron

  • Ferrous ammonium Sulphate or ferrous Sulphate @ 5g along with 2-3 g or citric acid per litre of water.
  • 2-3 sprayings at 4-5 day intervals.
  • Under high temperatures, spraying at low concentration of ferrous sulphate @ of 5 g/lt is necessary.


  • Ferrous sulphate FeSo4 7H2O (19% Fe).


Soluble Fertilizers


  • Soluble fertilizations are water soluble and are readily available to the plants in the pure form of nutrients.
  • These fertilizers can be applied through water as both basal in the form of fertigation and secondly as spraying on the plants directly with required quantity of water.


  • The use of proper quantity of fertilizers at appropriate time plays a vital role in increasing the productivity in the agricultural sector.
  • Fertigation, which combines irrigation with fertilizers is one of the recent advances in horticulture, is the most effective and convenient means of maintaining the specific requirement of each crop and soil.
  • Drip irrigation system, which is the most efficient method of irrigation for horticultural crops, offers an opportunity for precise application of water-soluble fertilizers and other nutrients to the soil, at appropriate time with desired concentration.

The most appreciable advantages of fertigation are,

  • Necessary fertilizers can be applied uniformly to each and every plant even on daily basis.
  • Fertigation when managed correctly, ensures localized placement of plant nutrients, movement of applied nutrients into the rootzone.
  • Labour and fertilizer saving.
  • Continuous supply of required nutrients during growing season.

Requirements of successful fertigation:

  • For the efficient and uniform distribution of plant nutrients, the irrigation system must fulfill certain requirements i.e.,
  • The system must be designed correctly and operate efficiently,
  • Ensure complete solubility of fertilizers without any residues and supply the nutrient solution at a constant rate and pressure from the mainflow line.
  • The fertilizer should not react with dissolved elements in water especially calcium and magnesium salts.
  • They must avoid corrosion, softening of plastic pipes and tubing and clogging of any component of the system.
  • If more than one material is used in preparing a concentration stock solution for subsequent injection into drip lines, the chemicals must not react each other to form a precipitate.
  • Now a days, fertigation, the new technique is gaining population in the irrigation technology in the developing countries.
  • Normally, the fertilizers are used as basal dose or top dressing.
  • The full year dose is split into one, two or three days.
  • Since these fertilizers are applied in bulk, lot of fertilizers go waste due to leaching, evaporation and fixation in the soil.
  • More over these fertilizers are transmitted to areas beyond in many cases, the effective utilization is less than 50% of the fertilizer applied.
  • Drip irrigation, which is the most efficient method of irrigation for horticultural crops like vegetables, flowers, etc., offers an opportunity for precise application of water-soluble fertilizer and other nutrients to the soil at appropriate time water the desired concentration.
  • This technique is popularly known as fertigation or fertilizer irrigation.
  • The most appreciable advantage of fertigation is that necessary fertilizer can be applied uniformly to each and every plant even on daily basis.


Organic Manures


Application of Organic Manures at the time of Land preparation

Broad casting of Chemical Fertilisers before sowing of seed

  • Organic Manures obtained either from cattle or plants.
  • Use of organic manures by farmers is an age-old practice in agriculture.
  • Organic manure's maintains better structure of soil improves water holding capacity of light soils
  • Improves aeration in heavy soils.
  • Food materials for millions of microbes
  • Microbes essential for mineralization process
  • Improves availability of nutrients from fertilizer sources.

Bulky Organic Manure's

  • FYM, Poultry manure, Municipal wastes, sheep & goat Manure's, vermiculture etc., Concentrated

Organic Manure's

  • Oil cakes (edible and non-edible).




Bio fertilizers are

  • Microbial products containing living cells of different types of micro organisms possess the innate ability either to fix or mobilize important nutrient elements from non-usable forms through biological process.
  • Needed to be applied to soil to enhance microbial activity in the rhizosphere
  • Playing a significant role in integrated plant nutrient systems (IPNS)

Types of Bio Fertilizers

  1. 1. Nitrogen fixers
  2. 2. Phosphate solubilisers

Nitrogen fixers

  • Among Nitrogen-fixers Azospirillum is widely recommended because of its easy adaptability and limited host specificity.
  • A micro Aerophilic bacterium
  • Associative symbiotic
  • Lives inside the cortical cells and xylem vessels of plant roots.
  • Also known to secrete growth promoting substances like gibberellic acid and IAA which enhance root proliferation and growth of crop plants.
  • Having ability to fix 25-40 kg Nitrogen/ha/year.

Phosphate solubilisers

  • Phosphorus in soil is in insoluble form due to fixation.
  • In this context the release of soluble phosphorus from fixed and insoluble forms in the soil aided by micro organisms assumes significance.
  • Belonging to the genera bacillus and pseudomonas.
  • Posses the ability to solubilize insoluble forms of phosphorus and make it available to plants.
  • Solubilization affected by the secretion of organic acids and enzymes which facilitate the crop to assimilate phosphorus easily.
  • Known to produce amino acids and growth promoting substances which help in better growth of plants.
  • Solubilise and made available about 30 kg P/ha/annum.

Biofertilizers Function/ Contribution Limitation Recommended Dose/ ha

Azospirillum (Associative)

10   15 % increase yield. Production of growth promoting substance

No limitation

2 kg /ha


Contributes to solubility of tricalcium, aluminum and iron phosphates making the phosphorus present in the soil available to plants.


2 kg/ha


Soil application

  • Mix Azospirillum and Phosphobacteria required for 1 ha (2 kg each) and add this mixture to 10 lit of water. Sprinkle the suspension on 100 kg FYM and mix uniformly.
  • Apply the mixture near the root zone along the planting rows and cover with soil.
  • Azospirillum and Phosphobacteria each at 2 kg/ha are to be mixed with 50 kg of well powdered decomposed FYM/compost.

Advantages Of Bio-fertilizers

  • Harnesses atmospheric nitrogen and makes it available directly to the plants.
  • Increases phosphorus uptake by solubilising and releasing unavailable Phosphorus.
  • Enhances root proliferation due to release of growth promoting hormones.
  • Increases the crop yields by 10 - 25 %.
  • Improves soil properties and sustain soil fertility.
  • Are cost effective and environment friendly.
  • Benefit to cost ratio of Bio-fertilizers is fairly high.

Precautions to be takern while application of Biofertilizers

  • Do not mix Bio-fertilizers with fertilizers, insecticide and herbicides.
  • Treat the seed with bio fertilizer with a gap of 24 hrs if seeds are to be treated with other types of dressing chemicals(fungicides, herbicides etc.,)
  • Store Bio-fertilizer packets away from sunlight or heat.
  • Use Bio-fertilizer before the expiry date indicated on the packet.
  • Irrigation has to be given after Bio-fertilizer application.


Andhra Pradesh