The irrigation programme must avoid any surplus of water in the soil as the saffron roots are highly sensitive to rot. Deep irrigation in the pre-planting phase is therefore highly effective, followed by rare but heavy applications of water due to the deep roots. From the early vegetative period, the soil depth must be taken into account for heavy spraying.
In deep soil with a high water retention capacity, 2 applications are generally sufficient, for example one before planting and the other during flowering. On light textured soil or when the evapotranspiration requirements are high, more than 3 applications may be necessary.
In regions where soya is irrigated, spray irrigation is used as part of large crop rotation.