Precipitation probability and water budgeting for crop planning in central Gujarat

The weekly water budget indirectly indicates the length of assured moisture availability for growing crops in the region (Singh et al., 2013). [...]keeping the above mentioned facts in mind, an attempt is made to analyze the daily precipitation data of sixty years at Vasad for initial, conditional and consecutive dry and wet week probability, weekly precipitation at different probability, monthly, seasonal, annual variations of precipitation and weekly soil water budget for crop planning in central Gujarat. The meteorological data from 1957-2016 recorded at ICAR-IISWC, Research Centre-Vasad (22°27'23.90"N Latitude; 73°4'43.08"E Longitude and 43 m above mean sea level) is used for probability analysis of precipitation, weekly soil water budget for crop planning. (3) STOR = AWC X e awc Where, STOR is actual storage of soil moisture in mm, AWC is soil moisture storage capacity in mm, ACC is accumulated values, P is precipitation in mm, ET0 is the reference evapotranspiration in mm. Annual, seasonal and monthly precipitation The mean annual precipitation of 868.2 mm at Vasad is distributed over 36 rainy days with CV of 42.2 per cent is given in (Table 1). The precipitation received during 43rd to 44th SMW is only 2-3 per cent of annual precipitation which is not enough for sowing of rabi crop. [...]rain water harvesting of surplus water is essentially required from 26th to 35th SMW to provide lifesaving irrigation to kharif crop at critical stages during dry spell and early sowing of rabi crop (mustard, wheat, fennel, rajgira etc.) by 46th SMW considering surplus water of 280.5 mm being utilized with 65-70% efficiency owing to inevitable losses given in (Table 2).