In a canal command, maize crop is grown in an area of 30 ha. The crop evapotranspiration (ETc) of maize is 840 mm per season and the effective rainfall during growing season is 20 mm. It is irrigated with water having salinity of 1.1 dS m⁻¹ by a surface irrigation method. If the leaching efficiency of the field soil is 0.8 and the average soil salinity tolerated by the maize crop for 100% yield is 1.7 dS m⁻¹, the depth of irrigation water in mm per season required to meet the seasonal ETc and leaching requirement will be _______.