Irrigation of crops or gardens
Watering a garden
This is a term which describes the method by which water is applied to crops. As watering is one of the most important garden operations, it is essential that the most efficient system be used. Such has been the progress with modern equipment that there is a large number of different types of water appliances on the market.
The selection must depend on the area of ground which has to be dealt with and the type of crop grown and its water requirement. One of the simplest forms of irrigation is practised in China where a large number of channels are dug out of fields so that water from a nearby river can be directed to water crops growing in the fields. This is not done in England but there are several simple methods which can be used.
One of these is by trickle irrigation. This takes the form of a length of thin plastic or rubber tubing which has nozzles fitted at regular intervals. When this tubing is connected to the water supply, the water percolates slowly through these nozzles and soaks the soil around them. If the tubing is arranged so that the nozzles coincide with individual plants, water requirement can be concentrated just where it is needed.
Gardeners will find this system one answer to the holiday watering problem especially as it can be used in the greenhouse or frames equally well. As watering or irrigation is particularly troublesome in the greenhouse, a special irrigation bench has been developed. This works on the capillary system where water is allowed to seep into a bed of sand on the staging. The sand is maintained in a moist condition all the time. Pot plants placed on the sand take up the moisture, aided in the case of clay pots by the use of a small piece of glass fibre wick which is inserted through the drainage hole on the pot’s base. Plastic pots do not require this as they are in closer contact to the sand owing to their thin section. One big advantage with this system is that plants can take up just sufficient water for their own individual needs.
For large areas of garden or growing crops, metal spray lines are ideal as these throw a large volume of water through holes or nozzles in the metal pipes. Pipes can be purchased in various lengths and can be quickly connected together so that very long rows of crops can be dealt with at one time. The more expensive systems are oscillating types which turn left and right by a water pressure operated unit at one end of the pipe line. The pipes are laid on low metal legs or supports above the crops. This system of irrigation is particularly suited to the commercial grower.
The amateur gardener can water quite large areas if he uses the oscillating type of sprinkler which can be set or ‘dialled’ to water preset areas. The water pressure drives a system of nylon gear wheels which turn the spray unit. Many models will work successfully on water pressure as low as 10-15kg (20-30lb) per 6 sq cm (sq in). Smaller areas can be watered in the same way if smaller models are used.
Irrigation can be employed in the form of revolving sprinklers which eject a fine spray of water over a circular area. In the more elaborate types the arc of working can be set or adjusted so that difficult areas (a wedge shaped area, for example) can be irrigated.
Successful irrigation also depends on having a good supply of water at convenient parts of the garden, especially if it is a large one. Although hose pipes are necessary for connection purposes to the various pieces of equipment used, convenient points in the garden will considerably facilitate irrigation plans. For this purpose alkathene tubing can be buried underground to connect to a series of stand pipes of the same material. To these can be fitted Hozelock hose pipe connectors and on/off switches.
Irrigation is important for plants grown under cloches and frames. Trickle irrigation lines under them laid on the soil by the plants will ensure that plenty of water will reach the roots quickly. There are some cloche and frame designs which have built-in irrigation in the apex of the roof. This usually takes the form of perforated pipe which, when connected to the hose pipe waters plants underneath by a fine spray of water.
There is no doubt that with a little ingenuity and with the aid of the modern equipment available, the average gardener can install an irrigation system in his own garden