Evaluation of water management systems in a tubewell irrigated farm

Land development, improved systems of irrigation and drainage, and proper irrigation scheduling are becoming more and more important for the success of command area development of the various major and minor irrigation schemes. For realistic planning and execution of such programmes or for improving existing ones, a systematic evaluation of the various components of the existing systems would be necessary but is invariably lacking. This paper presents an attempt made in this direction at C.S.S.R.I. farm, Karnal (India) to evaluate the integrated effect of water management technology on the efficiency of the irrigation system. The parameters selected for evaluation were the efficiencies of pumping, conveyance and field application. Besides these three parameters, water use efficiency, an index of crop production per unit of water applied, was also evaluated.Investigations revealed that pumping efficiency for electrically driven centrifugal pumps was about 52% and the corresponding value for diesel engine run pumps sets was 30%. The conveyance efficiency in the study area was as high as 93% because the seepage loss in the field channels laid in the alkali soils of the study area was only 7%. The field layout for water application in the study area consisted of long, narrow borders. The water application efficiency for this system was 58% for a wheat crop and 42% for rice. The overall system efficiency for wheat crops was observed to be 54% as against a value of 39% for rice.The observed average total water requirements and water use efficiencies for wheat were 46 cm and 70 kg/ha cm^?1 and for rice 150 cm and 46 kg/ha cm^?1, respectively. At these efficiencies, it was also noted that a cavity tubewell would command an area of 4.5 ha, with rice and wheat as the principal crop rotation.From this study, it can be inferred that reasonably high irrigation system efficiencies (54% as against the national average of about 30%) are possible with good water management at farm level.