Methods of fertilizer application:
a. Basal dose:
• Application of fertilizer/pesticides at the time of sowing
■ Phosphorus fertilizers applied at basal dose due to their slow release nature.
b. Deep placement of fertilizer:
■ In paddy only ammonium form (NI -14+ ) incorporated in reduced zone to prevent leaching and volatilization losses.
c. Starter dose:
• In legume and vegetable seedling at transplanting applied NPK at 1:2:1 ratio.
d. Split doses of N fertilizer:
• To increase N efficiency, applied 2 split doses in most of cereals having crop duration 45 months.
• Applied 3 split doses for crop having duration more than five months.
Suitability of fertilizers:
- Potassium sulphate is used where quality of crop is required because KCL reduce the quality of crops.
- For rice crop: ammonium sulphate is the best.
- In acidic soils: Rock phosphate and SSP is used instead DAP:
- In saline & alkali soils ammonical fertilizers are not recommended because alkalization of ammonia takes place
- Indian soils are universal deficient in Nitrogen and Zinc.
- Fertilizer grade indicate the percentage of plant nutrients in a fertilizer.
- Fertilizer ratio is the relative proportion of three major (NPK) plant nutrients.
- In water logged soils ammonium sulphate is best suitable N fertilizer.