Testing and Evaluation of Irrigation System

Water is the single input responsible for plant growth. This is received through rainfall, snow, mist etc Several types of plant-crops are raised to meet the growing needs of the population. The crop needs water indifferent quantities during the period of growth. Very rarely rainfall is received according to the needs of the crop. Therefore, it has become essential to construct dams on rivers for providing assured irrigation for crop production. In this context, it is necessary to consider the following factors :-

a) Fixing the quantum of the inflow into the reservoir.

b) Location of the best dam site.

c) Salinity and Alkalinity of the soil of the the water spread area.

d) Water quality-suitability for the irrigation.

e) Estimation of crop requirements of water with reference to the climate, season, soil, topography, consumptive use pattern, loss in conveyance of water, percolation elc.

f) Regulation of delivery of water from the dam plays a vital role in bringing the crop to the maturity. For every crop there are some critical stages of growth and during those stages it is most important to see that moisture stress is not felt by the plant system. If adequate quantity of water is not supplied during any stage, the yield will be substantially reduced.

A case study was made to evaluate the functioning of the irrigation system of the river Manjalr in Madurai district in Tamilnadu- This paper stressess the need to modernise the operation of this irrigation system for maximising the crop production by regulating the supply from the reservoir to the Command Area.