The choice or selection of agricultural equipment is dictated by a multiplicity of factors including the nature and size of the enterprise, the profitability and access to finance, the economic status of the region, the accessibility to a range of equipment options at local level, the ownership (individual, shared or cooperative) of equipment and access to mechanization contractors.
Alternatively, it may be applied on the surface of the ground or crop (e.g. grass) using a tractor mounted centrifugal spinner or oscillating spout type applicator where the fertilizer is broadcast rather than placed in rows. Aerial application of fertilizers may also be used in locations inaccessible to tractors, as described in Fertilizer Applicators and Plant Protection Equipment (EOLSS on-line, 2002). Both pressurized (typically using ammonia) and nonpressurized liquid fertilizer applicators are also described. Protection of plants from diseases and pests is normally achieved by atomizing a liquid formulation containing the active pesticide ingredient through a small nozzle under pressure and spraying onto, beside or beneath the crop canopy, or by using granular pesticide applicators.