Soil (Part II)soil ibps afo
Fertility, manure and fertilizers of Soil:
- Soil tilth:- Optimum physical condition of soil for crop growth.
- 16 important element for plant growth and are divided into Macro and Micro nutrient.
- L,Se,Ga,Al are beneficial elements
- Al and Sl are Ballast elements.
- Functional or metabolic nutrient term is given by Nicholas.
- Essentially of nutrient is given by Arnon
- Nitrate, Chloride and Sulphate remain in soil solution and are not absorbed by soil colloids.
- Diffusion enables nutrient movement without the movement of water.
- Role of Nitrogen:
- P & K utilization
- causes greenish colour, deficiency cause yellowing colour of leaves
- available in both anionic and cationic form
- Role of Phosphorus:
- helps in root growth
- grain formation and maturation of crops
- new cell formation
- improves quality of crop
- increase resistance to disease.
- Deficiency cause: discoloration of stem and foliage
- Role of Potassium:
- helps in resistance of pest and diseases
- improving the quality of tobacco and citrus.
- sugar and starch production
- 1st nitrogenous fertilizer- Sodium Nitrate
- Urea super granules urea formaldehyde,neem coated urea etc -Sow release N fertilizer
- Highest Nitrogen-82% in Anhydrous Ammonia
- Chilean Nitrate are useful in acid soil and are 16% in nitrate form.
- 33-35% N in Ammonium nitrate
- 26% N in Ammonium chloride – these are not recommended for tobacco, tomatoes and other such crops.
- 10-12% N in Dried bone meal
- 46% N in Urea.
Conservation measures of Soil and water:
- Intensity of hazards and limitations are depends upon Class of soil
- Class V
- no crosion hazarzard
- difficult to remove its limitatons
- Class VIII
- deserts, rivers washes, mine spoils and other barren lands.
- Diammonium Phosphate:(DAP):- 18:46:0
- K fertilizers are generally imported from Germany and France in India.
- SOP:- K2SO4, 48-52% K2O.
- MOP: KCl 50-63% K2O
- FYM has 0.15% of P2O5, 0.3% of N andK2O.
- Poudrette is also called Night soil.
- 2.95 kg of N can be obtained from 1 tonne of cow dung,2.95 kg of potash and 1.59 kg of phosphoric acid.
- Most widely used water-soluble P fertilizer in India:- Super Phosphate
- Soil test report have- pH, available NPK, Gypsum, Soil texture, EC, OC,and lime amount to be added, Green Manure/Compost in the flooding and training.
- Ph :
- Below 6:- acidic
- 6-8.5:- neutral
- 8.6-9:- tending to be saline
- above 9:- alkaline
- value of EC in dS/m (Total soluble salt)
- below 1:- normal
- 1-2:- critical for germination
- 2-4:- critical for growth
- above 4:- injurious to crops
Erosion and Conservation of Soil:
- 187.9Mha geographical area is affected by soil degradation.
Soil loss affecting factor:
- lateritic soils are less erodible than black soils
- 22m long and 9% slope is the ideal plot to calculate soil loss
- Order of soil loss
- Cultivated fallow land>bare fallow>Maize-wheat under up and down cultivation> Natural grasses
- Cultivated fallow>jowar>natural cover
- overgrazed fallow or maize>natural fallow
Size of Gullies:-
SymbolDescriptionSpecificationG1Very smallDeep:-3m,bed width:- 18mG2SmallDeep:-3m, bed width>18mG3MediumDeep:-3-9m, bed width>18m, slope:-8-15%G4Deep & Narrow
- Deep:- 3-9 m, bed width<18m
- Generally occurs in arid and semi-arid regions
- Saltation, suspension and surface creep- are 3typees of soil movement
- Saltation is important – in this particles of 0.1-0.5mm is lifted
- Suspension:- <0.1mm(dia) particles are lifted
- Surface creep:- 0.5-1mm particles are lifted.
- Soil loss:- Urad>Maize>Gora paddy>Ground nut