My citrus and pomegranate young leaves are yellow with a green net, how to fix iron chlorosis on high pH soil?

Yellow young leaves with green veins, returning every year on high pH soil, is classic iron chlorosis (lime-induced chlorosis) in citrus and pomegranate. On calcareous and alkaline soils, plain ferrous sulphate added to the soil gets oxidised and locked up quickly, which is why your soil applications did not work. The more reliable approaches in fruit trees are: first, foliar sprays of ferrous sulphate at a low concentration like 0.5 to 1 percent on the new flush, repeated a few times, which gives a quick green-up; second, soil application of a chelated iron specifically the EDDHA form, which stays available even at high pH, applied to the root zone, which is more expensive but works on these soils where ordinary iron fails. Alongside this, raise organic matter, avoid overwatering and waterlogging, and avoid pushing soil pH even higher. Please confirm with a soil and leaf test first, since the same yellowing can come from waterlogged roots, root disease or salinity rather than pure iron shortage. Match the product, dose and timing to your local KVK or horticulture department advice and do not over-apply.