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Soil Science Important Points (1)

Soil Science Important Points

Soil Science Important Points (1)

Exam Oriented Points

1.General Recommended Fertilizer Doses (N:P:K Ratio)

Cereal crops4:2:1
Pulses crops1:2:1 or 1:2:2
Oil seed crops 3:2:1
Fodder/Fibers crops2:1:4
Root crops2:1:1

2.Classification Of Irrigation Projects

 CCA: – Culturable Commend Area

ProjectCCA (ha)Cost (Rs)
Major  >10,000>50 Crores
Medium2000-10,0005 Crores to 25 Lacs
Minor<2000<25 Lacs

3.Composition of atmospheric air 

GasesVolume %
Carbon dioxide0.03

4.Character of Saline & Alkaline Soil

CharacterSaline SoilAlkaline Soil Saline-Alkaline
EC(dSm) at 25°C>4%<4%>4%

ESP = Exchangable sodium percentage
EC = Electricity conductivity 
pH = power of hydrogen

5.Pf  value

  • P means potenz its meaning power at 10.
  • Pis the scale like pH through which we measure the force with which water is retained in capillary or soil
Soil conditionPressure (atm/bars)Pf  value
Saturated soil0.0010
Field capacity1/32.53
Hygroscopic point314.5
Oven dry soil10,0007

    PWP = Permanent wilting Point

6.Measurement of irrigation water:

1 Cusec 28.3 liters
1 Cumec1000 liters or 10
1 ha mm10,000 liters 104
1 ha cm100,000 liters or 105
1 ha m 100,000,00 liters or 107

7.Carbon Nitrogen (C:N) Ratio 

C:N Ratio of MaterialC:N Ratio
Normal soils8:1 to 15:1
Legumes20:1 to 30:1
FYM25:1 to 30:1
Sawdust400:1 (Highest)
Micro-organism4:1 to 9:1 (Lowest)

8.Equivalent Acidity of  Fertilizers

Equivalent Acidity: The amount of CaCO3 required to neutralise the acid residues caused by acidic fertilizers in the soil e.g. 100 kg (NH4)2SO4 produces acidity which needs 110 kg of CaCO3 to neutralist it. Therefore equivalent acidity of (NH4)2SO4 is 110; Anhydrous NH3 has more equivalent acidity than other fertilizers.

FertilizersEquivalent Acidity
Anhydrous ammonia148 (Highest)
Ammoniunm chloride (NH4CI)128
Ammonium sulphate (NH4)2SO4110
Ammonium sulphate nitrate (NH4)2SO4NH4NO393
Urea80 – 85
Ammonium nitrate (NH4NO3)60
Mono-ammonium Phosphate55 (Lowest)

9.Equivalent Basicity of Fertilizers

Equivalent Basicity: Residual basicity caused by application of basic fertilizers, expressed in terms of CaCO3 equivalent of basic residues left by a fertilizer material (in kg/100 kg of fertilizer salt).

FertilizersEquivalent basicity
Calcium cyanamide (CaCN2)63
Sodium nitrate (NaNO3)29
Potassium nitrate (KNO3)29
Nitrate of Soda Potash26
Calcium nitrate Ca(NO3)21

10.Plants used for nutrient deficiency indicator

NutrientsIndicator plant
NitrogenCauliflower, Cabbage
PhosphorusMustard, Rapeseed
CalciumCauliflower, Cabbage
BoronSunflower, Sugar-beet
SodiumSugar beet, Turnip
FerrousSorghum, Citrus, Barley
Magnesium Potato, Cauliflower, Sugar beet
ManganeseSugar beet, Apple, Apricot

11.Sources of plant nutrients 

Nitrogen (N)Organic Matter
Phosphorus (P)Appetite
Potassium (K)Biotite, Orthoclase
Calcium (Ca)Anorthite, Dolomite
Magnesium(Mg)Dolomite, Olivine
Manganese (Mn)Pyrolusite
Ferrous (Fe)Pyrite
Molybdenum (Mo)Olivine

.Note:- More important soil Science Table Upload Soon

Important Table – 1Cl;ick
Important Table – 2Cl;ick
One LinerCl;ick
Fertilizers classificationCl;ick

Soil Science Important Points

Updated: 2020-09-22 — 12:00 am


Add a Comment
    1. The best platform for agri exams..

      1. It is un belivebable and it good plot form for all agriculture competetive purpose…Txs again sir

  1. Thank you so much..there is true hard work behind this…a very needed platform..thanks again..sir

    1. saurabh rastogi

      thank you so much sir

  2. Abhishek Siddharth

    Good Content It’s very useful apps for agriculture students for preparation any competitive exams

    1. Rakesh ashok patil

      Best that I have been before

  3. Very use full topic for all agriculture comptative exam thank you sir

  4. Good content provide agriexam

  5. Rupesh Tirunagari

    Small correction:- pF value at Hygroscopic coefficient should be 4.50. For Air dry soil it is 6 (pF) 1000 (atm).

  6. Very helpful Sir thank you so much sir

  7. Sir yeh Hygroscopic soil ka jo hai wo 4.5 pf hoga

  8. Sir table 4 plz check it
    Ph of saline akline soilis

  9. very important

  10. Informative sir

  11. Nyce sir ….thanku so much 🏝️🏝️🏝️🏝️🏝️🌈🌈🙏🏝️

  12. Really u people making us study without any trouble by providing study materials and important current affairs… There is no need to buy books for preparation.. Tq so much..

  13. Best for every agricultural examinations.
    Thank you Sir

  14. Un belivable

  15. very useful for any agriculture exam thank you sir

  16. Sir best notes till date. Please provide Pdf materials sir.

  17. It is un belivebable and it good plot form for all agriculture competetive purpose…Txs again sir

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