Importance Of Irrigation In Agriculture

.4 Water

Irrigation in agriculture is dependent on the availability of water of a suitable quality. Water quality is assessed by the potential problems which can develop as result of long-term use. The extent of potential problems varies and is determined by soil, climate and crop, as well as the skill and knowledge of the water-user. The judicial use of high quality water normally does not result in any problems. In practice however, a very large proportion of problems experienced are directly related to water use and quality. The quality of the water used for irrigation can for instance vary greatly depending on the soluble salt content. A variety of soil and crop problems could develop with an increase in salt content. Special management

If obtained from sources like rivers or boreholes, the salt and / or pollution levels should never rise above acceptable norms, as this will not reflect good agricultural practices. Water quality can be tested by a number of laboratories. Crops differ in their sensitivity to high salt concentrations in the irrigation water. It is important to know what the quality of water is suitable for the planned crop.

Irrigation Design

The microclimate of the area is a determining factor in the design of any irrigation system. This includes whether it is a summer or winter rainfall area, the average monthly precipitation, the average minimum and maximum temperatures, as well as the frequency, velocity and seasonal distribution of wind. The type of soil should be taken into consideration to ensure that the volume applied does not exceed the infiltration capacity of that particular soil. The rate of application must be calculated to supply in the crop requirement for optimal growth and production throughout the year.

Irrigation

According to the National Water Act (1998), the fair distribution of water is of extreme importance, and water measuring is applied to verify the extraction of water against an allocation. Most water sources are managed by Water Users Associations, which has to see to it that only the quantity of water allocated to each specific farm is pumped by or delivered to the farm for irrigation purposes. It is the farmer’s prerogative to utilise the allocated amount to the best of his ability through choice of irrigation system and good management. Water measuring, or determining of flow rate, is an aid for the effective distribution of water and is usually applied for the sake of legal requirements, management requirements, or both. A wide variety of measuring devices is available commercially and at the onset of implementation of water measuring, the following must be