Rice

Nutrient Management

Principles Nitrogen Phosphorus Potassium Sulphur Zinc Iron Organic Manures Foliar fertilizers 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)
  • Type of soil (Texturally, fertility status)
  • 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 nutrient requirement

    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 recover

    Example

    • 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/na, P = 2.5 - 3 Kg P/ha, K = 15-20 Kg
    • 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 Nis of the order of 35%, 45% and 65% of applied N respectively.
    • Therefore 1/3 x 30% + 1/3 x 45% + 1/3 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.

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    Nitrogen

    Introduction

    • 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 (volatalisation) when nitrate is exposed to anaerobic condition and leaching.
    • N loss is very high in flooded soils .

    Role Of N In Plant System


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

    N- Management In Rice


    15-20% in transplanted rice 30-35% in direct seeded rice 50% in upland rice
    Season x Utilisation of N
      Rainy season (Kharif) – Smaller N requirement
    Reasons: Less sun shine
    Less yield potential (Lower source, sink development)
    Dry seasons(Rabi / summer): Higher N –Requirement
    Reasons: More sunshine
    Greater yield potential (More source, sink development)
    Critical stages of N
      Sufficient N at tillering (adequate no of tillers/unit area)
    Sufficient N just prior to and during P.I (to ensure adequate panicle size)
    Sufficient N at grain filling (to ensure sufficient photosynthate production to fill the grains)
    N - Management
     

    Use more splits

    - for long duration varieties
    - for light textured soils
    - during dry season (Rabi or summer)

      Avoid large basal N application (Limited uptake since growth is slow during first three weeks after transplantation) Incorporate basal N into soil before planting / sowing Apply required N at tillering ( for more tillers i.e., source) Apply required N at P.I (for more panicles & grains i.e., Sink) Apply a late N dose (at flowering) only in dry season – long duration varieties – high yield potential . Create healthy reduced state by proper soil and water management. Healthy reduced zone helps in more absorption of ammonical – N on clay thus leaching and denitrification is reduced Iron and manganese availability is high H2S is not formed – even formed precipitated by Fe Prevails optimum pH (6.5 – 7.0) leads to availability of all major and minor nutrients.

    Steps for increasing N –use efficiency

    • Apply right quantity at right time by right method.
    • Root zone placement of N 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 (400-450 panicles / mt2)
    • Proper water management practices.
    • Effective weed control.

    The inorganic fertilizers

    Name of the fertilizer
    N %
    Remarks
    Urea
    44.0 – 46.0

    *Urea, Ammonium sulphate nitrate, Calcium ammonium 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.

    Ammonium Sulphate
    19.9 – 20.0
    Ammonium Sulphate Calcium Nitrate
    26.0
    Ammonium Nitrate
    25.0
    Ammonium Chloride
    25.0
    Calcium Nitrate
    13.0 – 15.0
    Sodium Nitrate
    16.0
    Calcium Cyanamid
    21.0
    Anhydrous Ammonium
    82.0

    Ammonium Nitrate

    32.0 – 35.0

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    Phosphorus

    Introduction

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

    Role Of P In Plant System

    • Stimulates growth and development of roots

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

    Deficiency Symptoms

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

    Injury Due To Excess P Application

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

    In organic fertilizers

    Group

    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    

    D) Basic slag - 3.0 – 8.0 -
    * Mussori - 23.0 – 24.0 -
    * Purulia - 23.0 -  


    Sources Of P:

    Organic Manures

    Material
    Phosphate (P2O5) (per cent)
    Farm Yard Manure 0.4 – 0.8
    Compost (Urban) 1.0
    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

    Deficiency Symptoms


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

    P - Management In Rice

    • 2-3 kg P is required for producing one tone of grain.
    • P fertilizer requirement is smaller in rainy season (less sunshine smaller potential yield), larger in dry season (more sunshine, greater potential yield).
    • P –Fertilizer should be applied before transplanting, since O is required in the initial stages of crop for root and tiller development.
    • P is highly immobile, hence applied nearer to root zone before transplantation.

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    Potassium

    Introduction

    • One of the three major nutrients.
    • Majority of soils are rich in potassium.
    • Mobility is less than N and more than P
    • Needs larger quantities by crop.
    • K requirement is slightly smaller in rainy season over dry season.
    • Excess quantities of hydrogen sulphide, organic acids, Carbondioxide and ferros iron retards potassium uptake.
    • Excess Na and Ca in soil retards K absorption.

    Role In Plant System

    • Involves in working of enzymes.
    • Production and movement of photosynthates to sink
    • Helps in proper uptake of other nutrients.
    • Influence tillering or branching of plant
    • Influence size and weight of grain
    • Induce tolerance in plant against stress (biotech and abiotech)
    • Made the plant tolerant to pests and diseases.

    • Reduce adverse effects of unfavourable climatic conditions.

    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 -

    Sources Of K:

    Organic Manures

    Material
    Potash (K2O) (per cent)
    Farm Yard Manure
    0.5 – 1.9
    Compost (Urban)
    1.5
    Compost (Rural)
    0.7 – 1.0
    Green Manures
    0.6 – 0.8
    Non-Edible Cakes
    Castor cake
    1.0 – 1.1
    Cotton seedcake (undecorticated)
    1.6 – 1.7
    Mahua cake
    1.8 – 1.9
    Karanj cake
    1.3 – 1.4
    Neem cake
    1.4 – 1.5
    Safflower cake (undecorticated)
    1.2 – 1.3

    K Management In Rice

    • Potassium can be applied as basal dose along with phosphorus in the last puddling.
    • For long duration varieties and high yielding varieties potassium can be applied in two splits i.e., as basal and at panicle initiation.

    Deficiency Symptoms

    • Brown yellow discoloration of old leaves, spreading inward from tip.
    • Irregular necrotic spots on the leaves and panicle
    • Lodging of crop due to weakening of stem.
    • More chaffy and shriveled grains.
    • Reduction in yield and crop quality.
    • K deficiency is frequently accompanied by Helmetnhosporium leaf spots.

    Injury Due To Excess K Application

    • Leads to calcium, magnesium and iron deficiencies.

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    Sulphur

    Introduction

    • It is one of the important plant nutrients after N,P & K.
    • Due to non availability of fertilizers like ammonium sulphate and continuous use of nitrogenous fertilizers like urea sulphur deficiency is seen in some of the regions.

    Role in plant system

    • Neccessary for protein synthesis.
    • Part of amino acid cysteine
    • Important for chlorophyll formation.

    Sources


    Fertilizer
    S %
    Ammonium sulphate
    23
    Single super phosphate
    11-15
    Potassium sulphate
    17-18
    Gypsum (an hydrous)
    23
    Gypsum (usual)
    18

    Deficiency Symptoms

    • Pale yellow or light green leaves.
    • Retarded growth.
    • Delayed maturity.
    • Poor tillering.

    Injury Due To Excess Fertilizer

    • Necrosis of leaves
    • Growth reduction.
    • Dark color of leaves.

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    Zinc

    Introduction

    • Zinc importance in plant nutrition is recognised after the introduction of high yielding varieties.
    • Zinc deficiency caused by intensive cropping.
    • 80% of rice land deficient in zinc.
    • After N and P zinc playing important role in rice.
    • To get full benefits of N,.P,K, 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 N – metabolism.
    • Regulate auxin (harmone) production
    • Promotes nucleic acid production for protein synthesis.

    Sources

    • Zinc sulphate – ZnSO4 7H2O (21%Zn)
    • ZnSO4 H2O (33% Zn)
    • Chelate Zinc (12% Zn)

    Deficiency Symptoms

    • Appearance of rusty brown spots and discoloration of older leaves starting from 2-3 weeks after planting.

    • Uneven crop stand.
    • Under acute conditions margins of older leaves dry up.
    • Tillering and growth adversely affected (KHAIRA disease)
    • Fresh leaves smaller in size.
    • No uniform maturity of crop.

    Management of Zinc for Rice

    • 50 kg of Zinc Sulphate /ha to soil in the final puddling in every Rabi season in double cropped wet lands. Once in 2-3 crops in single cropped areas..

    • Give a gap of 4-5 days between application of phosphorus and Zinc since Zn has antogonistic effect with phosphorus.
    • Zinc deficiency an standing crop can be corrected by spraying 0.2% zinc sulphate solution (2g/lt of water) about 500 liters of spray solution is required to cover one hectare.
    • Spraying should be repeated 2-4 times at an interval of 5-10 days.

    Injury due to Excess Fertilizer

    • Excess zinc cause deficiency of Iron.

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    Iron

    Introduction

    • Iron deficiency in rice in now a days very common particularly under rainfed or irrigable dry conditions.
    • Deficiency of Iron also seen where excess calcium applied.
    • In high pH soils Iron deficiency is common.
    • Excess application of P, Mn, Cu, Zn 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.

    Sources

    • Ferrous sulphate FeSO4 7H2O (19% Fe).

    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.

    Management Of Nutrient Iron

    • Ferrors ammonium sulphate or ferrus sulphate @ 20-30 g 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 ferrus sulphate @ of 5 g/lt is necessary.

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    Organic manures

    Intorudction

    • 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.

    Organic manures

    Bulcky organic manures

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

    Concentrated organic manures

    • Oil cakes (edible and non-edible)

    Nutirent composition

    • Organic Sources

    Material
    Nitrogen (N) (per cent)
    Farm Yard Manure 0.5 – 1.5
    Compost (Urban) 1.0 - 2.0
    Compost (Rural) 4.0 - 0.8
    Green Manures 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

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    Foliar fertilisers

    Introduction

    • In recent years soluble fertilizers otherwise known as foliar fertilizers were introduced in A.P on the names of Polyfeed and Multi ‘K’
    • Polyfeed contains 19 : 19 : 19 NPK with 6 micro-nutrients like iron, manganese, boron, zinc, copper and molybdenum, while multi K contains 13 : 0: 46 NPK.
    • These fertilizers provide nutrients to the plant by foliar application as these fertilizers are completely soluble in water.
    • These fertilizers have no other impurities like sodium and chloride and they are 100 % nutrients and these nutrients are easily absorbed through the leaves.
    • In certain occasions the existence of prolonged drought there is no scope to apply fertilizers to the soil for want of moisture. Like wise in flooded conditions due to continuous rains fertilizers could not be applied to the soil.
    • In such special circumstances these soluble fertilizers are must to protect the crop against hunger and this forms a compulsory act of crisis management.
    • In such circumstances the foliar application of Speciality fertilizers play an important role in supplying the nutrients at critical stages of flowering and fruit development.
    • The experiments conducted in different countries indicated that these soluble fertilizers as supplement to soil application of fertilizers enhances the production per unit area ranging from15-25%.
    • The trials conducted in Andhra Pradesh and Tamilnadu also indicated that the use of Speciality fertilizers enhance the yields in several crops like Paddy by 10%, Pulses, Chillies, Cotton, Groundnut by 20% and Cashew and mango by 20%

    Types of fertilisers

    • Multi – K 13% Nitrogen and 46% K
      Polyfeed 19:!9:19 N: P:K and 6 micronutrients These Speciality fertilizers are to be applied at the recommended concentrations.
    • These fertilizers are compatable with insecticides and fungicides except sulphur

    Speciality Fertilizers
    Other Fertilizers
    Solubility Fully water soluble. Dissolves rapidly in water and remains in solution without impurities, (detrimental chloride and sulphate). Not water soluble and leaves soluble deposits with impurities except urea.
    Absorption Plant nutrients are ionic form(chelated) and available for plant absorption. Multi'K' K= (K) = N = ( NO3) polyfeed N = NO3NH4 and P =(PO4) K =(K+) and Fe , Mn, B , Zn, Cu, Mo in PPm Mostly in oxidized salt form. MOP in K2O, SOP in K2O, CSP in P2O5 , N fertilizers mostly in salt conditions except urea.
    Activity Plays vital role in plant metabolic activities and also plant food. Utilized as plant nutrient (food)
    Yield Exploit fully yield potential in quality and quantity by increasing 15 - 20% Yield at suggested dosage 1% - 2% spray Increased yield if applied in balanced ratio ( proportion) NPK ( 4 : 2 : 1)

    Application

    • Application is suggested at different critical plant stages as nutritional foliar spray and fertilization.
    • Eg: Before reproductive stage and after grain setting at 1% spray of multi K.

    Results

    • The experiments conducted at NARDI indicated that foliar spray of 1 % either polyfeed or Multi ‘K’ at 45, 60 and 75 days after planting increased the rice yield by about 10 % over unsprayed control.
    • Observation trials conducted by KVK (NFCL) indicated that foliar application of Multi ‘K’ at 1 % at the time of maximum tillering and prior to panicle initiation resulted in increased yield of 16.8 % over untreated control.

    Fertilizer Recovery

    • Recovery of top dressed fertilizer varies throughout the life cycle( mainly as a function of root growth) In terms of N recovered from fertilizer N applied (%)
    • Basal 15-30
    • At midtillering 30-50
    • At panicle initiation 45-75
    • At flowering 35-60

    Phosphorous and Potassium

    • P and K are typically applied as basal application , although application at 10 DAS in direct sown crops may improve the recovery efficiency of P applied from 20-35%. K can also be split and the K split 50% basal and 50% at PI but this is mainly to improve pest resistance.

    Nutrient Conversion Factors


    Elemental to oxide
    Conversion factor
    P to P2O5
    2.29
    K to K2O
    1.2
    Oxide to elemental
    Conversion factor
    P2O5 to P
    0.437
    K2O to K
    0.830

    Quantities of Fertilizers required to provide a particular quantity of nutrient

    Quantity of Nutrient Kgs (1 Kg)
    Fert quantity in Kgs
    N
    2.2 Kgs of Urea
    P
    6.3 Kgs of Super phosphate
    K
    1.7 Kgs of Muriate of Potash

    Benefits Polyfeed

    • Readily taken up by plants, correct deficiencies of both macro and micro nutrients.
    • Immediately increases grain size.
    • Improved protein content in grains .
    • Efficient utilization of all nutrients.

    Multi ‘ K ‘

    • Efficient utilization of nutrient in the plant.
    • Induces panicle initiation.
    • Induces resistance from pests and diseases .
    • Imparts drought and lodging resistance.
    • Improved protein content in grains .
    • Improves crop quality .

    Results

    • The experiments conducted at NARDI indicated that foliar spray of 1% either polyfeed or Multi 'K' at 45,60 and 75 days after planting increased the rice yield by about 10% over unsprayed control.
    • Observation trials conducted by KVK (NFCL) indicated that foliar application of Multi 'K' at 1% at the time of maximum tillering and prior to panicle initiation resulted in increased yield of 16.8% over untreated control.

    Fertiliser recovery

    • Recovery of top dressed fertiliser varies throughout the life cycle (mainly as a function of root growth).
    • In terms of N recovered from fertilizer N applied (%)

    Basal 15-30

    • At midtillering 30-50
    • At panicle initiation 45-75
    • At flowering 35-60

    Phosphorus and potassium

    • P and K are typically applied as basal application, although application at 10 DAS in direct sown crops may improve the recovery efficiency of P applied from 20-35%.
    • K can also be split and the K split 50% basal and 50% at PI but this is mainly to improve pest resistence.

    Straw management

    • Early tillage and aerated decomposition of residues leads to improved nutrition of the subsequent rice crop due to enhanced N mineralisation and P release.

    The general nutrients requirement Kg per of the crop (grain and straw requirement)


    N
    P
    K
    S
    Ca
    Mg
    Grain%
    1.05-1.4
    0.15-0.25
    0.25-0.33
    0.06-0.15
    0.05-0.09
    0.02-0.03
    Straw%
    0.5-0.8
    0.05-0.1
    1.3-2
    0.05-0.1
    0.03-0.17
    0.15-0.16
    Crop uptake Kg/t grain
    15-22
    2-4
    15-25
    0.15-0.25
    -
    -

    • The fatest breakdown of straw is when the soil is moist (about 60%) of water holding capacity, not wet (saturated) not dry.
    • Thus water can be saved by not saturating soil weeks in advance. At the same time saturating fields for less time will improve mobility and field uniformity.
    • Around 50% decomposition of straw can occur in a normal fallow period of 2 months between two crops without any additional water the only requirement is a shallow dry incorporation after harvest.
    • Thus when weather permits shallow dry tillage is to be is to be the standard practice It will reduce water requirement.

    The benefits include

    • Recycling of nutrients from straw without the trouble involved in common late incorporation and decomposition under anaerobic conditions.
    • Improved reoxidation of the top soil layer during the fallow (important for long term sustainability of soils)
    • substantial water savings.
    • Cracking of soils is reduced and land soaking for the subsequent crop can be done much faster.
    • Volunteer control: The advantages of a plough versus grass fallow are yet to be evaluated, but a shallow plough fallow seems to have advantage of improved residue decomposition and decreased water requirement when the field is wetted.
    • If weather permits, the field should be dry tilled within two weeks of harvest.

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    Biofertilizers

    Intorudction

    • 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 acitivity in the rhizosphere.
    • Playing a significant role in intigrated plant nutrient systems(IPNS)

    Types of bio fertilisers

    • Nitrogen fixers
    • Phosphate solubilisers

    Nitrogen fixers

    • Among N-fixers azopirillum is widely recommended because of its easy adaptability and limited host specificity.
    • A micro aeropholic 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 N/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 general 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.
    • Solublize and made available about 30 Kg P/ha/annum.

    Applications


    Bio fertilizers
    Function / Contribution Limitation Recommended Dose / ha
    Azatobacter (Non-symbiotic) 20 – 25 kg N / ha Demands high organic matter 2 kg / ha
    Azospirillum (Associative) 10 – 15 % increase yield. Production of growth promoting substance No limitation 2 kg /ha
    Blue Green Algae or Cyanobacteria (Phototropic) 20 – 30 kg N /ha 10 – 15 % increase in yield. Production of growth promoting substance Effective only in submergence rice and demands bright sunshine 10 – 15 kg/ha
    Azolla (Symbiotic) 30 – 100 kg N/ha , Yield increases 20 – 25 % Survival difficult at high temperatures, great demand for phosphorus and used in flooded rice 10 tons/ha
    Phospho Bacteria 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.
    • Apply the mixture of biofertilisers to the rice before transplanting.

    Seed Treatment

    • Prepare a slurry of Azospirillum 600 g +phosphobacteria 600 g with one litre rice gruel and mixed with 25 kg of rice seeds and ensure uniform seed coating.
    • Dry in shade and sow the seeds within an hour of treatment.

    Advantages Of Biofertilizers

    • 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 harmones.
    • 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 biofertilizers is fairly high.

    Precautions To Be Taken While Application Of Biofertilizers

    • do not mix biofertilizers 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 biofertilizer packets away from sunlight or heat.
    • Use biofertilizer before the expiry date indicated on the packet.
    • Irrigation has to be given after biofertilizer application.

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