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:
  1. P & K utilization
  2. causes greenish colour, deficiency cause yellowing colour of leaves
  3. available in both anionic and cationic form
• Role of Phosphorus:
  1. helps in root growth
  2. grain formation and maturation of crops
  3. new cell formation
  4. improves quality of crop
  5. increase resistance to disease.
  6. Deficiency cause: discoloration of stem and foliage
• Role of Potassium:
  1. helps in resistance of pest and diseases
  2. improving the quality of tobacco and citrus.
  3. 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
  1. no crosion hazarzard
  2. difficult to remove its limitatons
• Class VIII
  1. deserts, rivers washes, mine spoils and other barren lands.

Complex Fertilizers

• Diammonium Phosphate:(DAP):- 18:46:0

Potassic Fertilizers:

• K fertilizers are generally imported from Germany and France in India.
• SOP:- K2SO4, 48-52% K2O.
• MOP: KCl 50-63% K2O

Manures:

• 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.

Phosphatic fertilizers:

• Most widely used water-soluble  P fertilizer in India:- Super Phosphate

Soil Testing:

• 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 :
  1. Below 6:- acidic
  2. 6-8.5:- neutral
  3. 8.6-9:- tending to be saline
  4. above 9:- alkaline
• value of EC in dS/m (Total soluble salt)
  1. below 1:- normal
  2. 1-2:- critical for germination
  3. 2-4:- critical for growth
  4. 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
  1. Cultivated fallow land>bare fallow>Maize-wheat under up and down cultivation> Natural grasses
  2. Cultivated fallow>jowar>natural cover
  3. 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

1. Deep:- 3-9 m, bed width<18m
2. Deep>9m

Wind erosion:

• 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.

Agronomic measure:

• Soil loss:- Urad>Maize>Gora paddy>Ground nut