Typical Fertigation Application Rates 2 to 20 L/ha Apply toward the end of the irrigation shift. Know your injection lag times and allow adequate time, following the injection of the product, to flush the irrigation system out with clean water, including all mainlines, submains and lateral delivery systems. Other Application Rates 10 to 50L/ha as a directed soil spray, prior to planting or banded under canopy, with 200 to 1000L/ha water, or irrigated in after application (depending on crop).