Overhead sprinkler irrigation is the most versatile method of irrigation and is suitable to almost all crops, soil types, field shape and topographical conditions.
A typical overhead sprinkler irrigation system consists of a mainline from pump to field, submains then break the field into small blocks. The submain has a series of hydrant valves which supply water into the lateral lines. 3/4" Impact sprinklers or 1/2" mini sprinklers mounted on riser pipes are equally spaced along the laterals.
Alternation in riser heights, spacing of sprinklers & laterals and water application rates make these systems suitable for almost any crop and soil type; their flexibility will adapt to any shape of field and topographical conditions.
Systems range from Fully-Portable, made up of a series of light-weight pipeline sections, either aluminium or polyethylene, that are moved manually from one area to another. After a section of the field has been irrigated the hydrants are closed and the laterals carried to the next position. The entire system from pump to to sprinklers can be dismantled and moved to another field or even a totally different farm. They are normally the lowest cost and most versatile sprinkler systems, they are however quite labour intensive. Semi-Portable usually have a permanent pump-station and underground mainline with portable submains and lateral lines, while in Solid-set systems all components are permanent fixtures and are usually electronically controlled requiring very little human operation.
High coefficient of uniformity and overall system efficiencies can be achieved with a system carefully designed to match the sprinkler spacing, nozzle size and the infiltration rate of the soil.
We strongly advise against the use of "big gun sprinklers" on any crops , since they have very poor uniformity in the distribution of water meaning that vast quantities of water and therefore energy is wasted, additionally their large droplet sizes compact the soil and damage plants; this is particularly true on crops such as tobacco and where the quality of leaf determines it's value, or on vegetables which can become bruised.