Fertilizers may be scattered over the surface of the soil or placed around individual plants. Some fertilizers are available in liquid form for application to the soil surface or as foliar feeds directly onto leaves.
When applying fertilizers always use gloves and do not breathe in any of the dust or vapour arising from them. Use only the recommended quantities since too much fertilizer can damage plants.
Scattering fertilizer over the entire soil surface benefits the greatest area of soil and minimises the risk of plant injury from overfeeding. In dry weather however, the uptake of the nutrients may be poor, particularly of immobile nutrients such as phosphates. So whenever possible dig phosphates into the soil.
When broadcast fertilizing do not allow any of the material to touch the leaves or stems of plants as this may result in scorching.
To apply fertilizer in accurate amounts over large areas mark out the plot into square metres using string or canes. Fill a pot or bowl with the recommended amount of fertilizer and sprinkle it evenly over each section of the plot.
Fertilizing around the base of a plant (but not allowing to touch the stem) is an economical and efficient feeding method as plant roots quickly spread through the fertilised area.
Dissolving fertilizer in water before application is a particularly efficient method of applying nutrients, especially if the soil is dry. Do not use liquid feeds when rain is forecast since the liquid may be washed away. Apply the feeds early in the day to avoid possible sun scorch.
These may be used to correct mineral deficiencies that are caused by certain soil conditions, such as high Ph. For deep rooted plants such as fruit trees, foliar feeds may also be used to correct deficiencies in nutrients that are relatively soluble.