Advantages of Irrigation over natural water supply

Wherever irrigation has been applied on farm land it has yielded several advantages over natural water supply especially by rain.
Under irrigation cultivation can be carried out all the year round and this ensures better and maximum utilisation of land-
It allows diversification of agriculture in areas with harsh climate- In addition to pastoral farming crops can be introduced in dry regions. Besides, a wide range of crop can be grown on irrigated lands.
Water supply by irrigation is regular and more reliable while natural supply is seasonal and sometimes highly unpredictable.
Irrigation water adds some plant nutrients to the soil. This is been realised more particularly in areas where water is drawn from rivers originating m Volcanic highlands. Such water contains dissolved and suspended minerals like iron, copper, potash, magnesium and calcium.
Irrigation water can be used for other purposes like fish farming. For example, the Wet Rice farming in Thailand and China stock the irrigated fields with fish in order to get animal proteins in their diet.
It facilitates the formation of a deep workable soil especially in arid lands with a thin layer of weathered soil. When applied on crop fields water accelerates chemical decomposition and-decay of the semi-weathered rocks.
In the very "dry areas experiencing high rates of evaporation from the soil, irrigation ensures controlled flow of water through the soil and this helps to lower its salt content (of the soil).
Irrigation also minimises leaching i.e the washing down of plant nutrients from the top layers of soil. This is so because irrigation water is not as strong as rainwater and its flow through the soil is regulated.
Modern irrigation devices have been designed m a multi-purpose way. Dams which regulate fee flow of water to farmlands may also be used to control floods, generate electricity and also to improve on the navigability of rivers.
Irrigation minimises, and in some cases does not at all allow, soil erosion. This is True since irrigation water is not as torrential as some down pairs of rain which may lead to surface run off and eventual erosion.
Over centuries several methods of moving water from reservoirs to farm lands have been developed. The various changes taking place in global technology, especially in the western world, have produced more efficient devices. Certainly the method to be used for supplying water in a particular area will depend on several considerations such as the distance over which water is to be moved, depth of the reservoir, degree of aridity or length of tile dry season and the level of technology reached by the fanning community.