The different methods of fertilizer application are as follows:
Deep Soil Application
Organic manures are sometimes placed on the surface of soil and incorporated into the soil with a plough or rototiller before planting. Fertilizer can also be applied in bands at the bottom of plough furrows or broadcast or spread on top of ploughed soil that is then worked into the soil with a harrow before planting.
Broadcasting
You can use a walk-behind drop spreader or hand-held spreader with a crank to scatter granular or bulk fertilizer on the ground. This method, called broadcasting, is good for flowerbeds, lawns, trees and vegetable gardens. Fertilizer may be broadcast on of the ground before planting and then tilled or watered into the soil. If it is broadcast on growing plants and watered into the soil, it is called topdressing.
Banding
To fertilize a row of flowers or vegetables or to get plants started, place the fertilizer 2 inches to the side and 2 inches deeper than the seed furrow. This is called banding. When you irrigate with furrows, place the band of fertilizer between the irrigation furrow and the seed furrow. Place bands of fertilizer on each side of the furrow. When you irrigate with a drip hose, place the fertilizer under the emitter. You can also place the fertilizer on one side of a seedling or on one side of a plant mid-way through its growing period. This is called side dressing.
Liquid Application
Water-soluble fertilizer can be applied with spray cans or applied with sprinklers or furrow irrigation. Small amounts of liquid fertilizer applied to young vegetable plants at the time of transplanting is called a starter solution. Some plants require micronutrients such as zinc and iron that they cannot get through the soil, but their leaves can absorb them. Water-soluble fertilizer is usually sprayed on leaves when they first show signs of nutrient deficiency and in periods of drought when the soil is to dry to absorb the nutrients. There are drawbacks. If you use a solution that is too strong you might burn or scorch the leaves. You can only apply a small amount of nutrients in a single spray. This method is costly unless you combine the fertilizer with pesticides to control insects or disease.