Soil Fertility and Nutrient management (1+1)

I. Application of fertilizers in solid form

• Solid fertilizers of straight or complex or mixed NPK fertilizers are directly applied to soil by adopting different methods of application based on the type of crop, season, age of the crop, type of fertilizer and their concentrations.

1. Broadcasting:
It is a process where the fertilizer is spread over the entire soil area evenly and uniformly. This may be done before the land is ploughed, before planting or while the crop standing. It may be of two types
a. Broadcasting at planting or sowing: During sowing time, fertilizers are uniformly spread over the soil and mixed properly.
b. Broadcasting as top dressing: Followed for closely spaced crops. It may be made at the time of critical crop growth period. It is essential to note that the fertilizers are not to be applied when the leaves of plants are wet. This may create injury to the leaves or direct fall of fertilizer granules like urea or KCl on leaves leads to leaf scorching
Advantage: Easy, simple, less cost (Labour), no special equipment, large quantity of fertilizer can be applied.
Dis-advantages: (Over placement)
1) Uneven distribution of fertilizer which causes a ranked (un uniform) growth of crop
2) Loss of nitrogen through volatilization, erosion
3) It requires relatively large quantity of fertilizers.
4) Costly fertilizers cannot be applied by this method, requires experience and skill of application.
5) Fixation of nutrients especially PO4 and K due to contact of large volume of soil compare to that of placement.
6) Stimulates the more weed growth

2. Placement:
Fertilizers are placed in the soils irrespective of the position of seed, seedling or growing plants before sowing or after sowing the crops. The following methods are most common;
a) Plough- sole placement: It is applied in a continuous band at the bottom of the furrow during the process of ploughing
b) Deep placement: It is specially followed in paddy fields for placement of N fertilizers ((NH4)2SO4 and urea) in the reduced zone. It prevents loss of ammonia and makes the nutrient easily available to crop. The fertilizer is applied under the plough furrow in the dry soil before flooding the land and making ready for transplanting.
c) Sub soil placement: It is recommended in humid and sub humid regions where sub soils are strongly acid. P & K fertilizers are used.
d) Localized placement: Application of fertilizers in to the soil close to the seed or plants in bands or in pockets. Only small quantities of fertilizers are applied. It reduces fixation of P & K. It includes
i) Drill placement or contact placement or combined drilling: Drilling of seeds and fertilizers together while sowing in the same row. Old method and useful for PO4 and potash fertilizers in rainfed areas.
ii) Band or hill placement: When the plants are placed 3 feet or more on both sides fertilizers are placed close to plants in bands on one or both sides of the plant. It is practiced for N & P Fertilizers to orange, banana, papaya, apple, pear, coconut, cashew nut and other fruit trees.
iii) Row placement-Fertilizers are applied in rows
iv) Side dressing- Fertilizers are applied between the rows (followed for Vegetables and fruit crops)
v) Pellet application – Make pellet form (1:10 ratio of fertilizer (N) & soil and make it to dough) and apply to soil.
Advantages of placement/Banding
1) Fixation of nutrients appreciably reduced.
2) Never harms plants and seeds.
3) No weed growth (weeds do not get nutrients)
4) There is no volatilization loss of N
5) It gives better residual effects and every unit of nutrient is effectively utilized (better FUE)
6) Smaller quantities of fertilizers can be effectively applied; both solid and liquid fertilizers are applied.
7) It is best method for P & K application.
8) It is useful for widely spaced crops, quick growing crops, dry land crops.
Dis advantage: High labour cost and requires specialized equipments.
Top