Evaluating Agricultural Land Drainage Need in Soils of Tawa Command

The drainage need in soils of Tawa Command was evaluated in terms of drainage coefficient For the purpose 33 years daily rainfall data of the command was used for its depth-duration-frequency analysis to arrive at one to four consecutive days rainfall values for 2,5, 10 and 20 years recurrence interval (R.I.) computed drainage coefficients indicate that the soils of Tawa command having basic infiltration rate 8,9,10 and 11 mm/hour, may not need surface drainage system for one day period rainfall of2,5, 10 and 20 years R.I. respectively The corresponding values in case of two consecutive days rainfall are 6.7 8 and 9 mm/hour. Study further reveals that Tawa command predominetly having clayey soils may necessarily have to he provided with surface drainage system for its existing major crop sequence soybean followed by wheat When one day rainfall is considered, the drainage coefficient varies between 161mm to 209 mm/day for 5 years R.I. and between 197 mm/day to 245 mm per day for 10 years R.I. in clayey soil of Tawa Command having basic infiltration rate between 1 to 3 mm/hour However in case of two consecutive days rainfall the corresponding values of drainage coefficient are 92 to 140 mm/day for 5 years R I and 117 to 165 5 mm/day for 10 years R I.