Climatic parameters and net irrigation requirement of crops

The major meteorological data like temperature, relative humidity, rainfall, wind speed and sunshine hour for a period of 21 years was collected and analyzed. This was done for planning of irrigation strategy and to develop an appropriate irrigation scheduling for different cropping systems. Probability analysis, evapotranspiration and net irrigation requirement were estimated. For recurrence interval of 2, 5, 25, 50 and 100 years, the values of maximum rainfall found in June were 470, 660,790, 910, 982 and 104 mm, respectively. The highest ETp (6.49 mm day(-1)) was obtained in April and the lowest (3.68 mm day(-1)) in July. The maximum net irrigation requirements for crops were found in the months of April, November, February, and January, respectively. May to September was the highest rainfall months when the rainfall was more than 300 mm in over 63.80% of the years and was always more than 50 mm. It appears that rainfall can be delayed upon during June and water resources can be brought into consideration to share the excess water for agricultural use in drought months. Effort was to be made to conserve for winter period as most of the month indicate drought by soil conservation. The results further indicate that net radiation generally decreased during monsoon reaching its minimum in December and then gradually increased again with the onset monsoon summer, finally reaching its peak in May. Latent heat flux ranges from a minimum of 213.52 ly/day in July to maximum of 387.83 ly/day in March.