A hard crust forms after I irrigate and my seedlings cannot come up, what helps?

A hard crust after watering usually forms on soils low in organic matter, where heavy flooding or rain hits the bare surface, the fine particles seal together, and then dry into a hard cap that the tender seedlings cannot push through. It is worse on sodic or poorly structured soils. To get this crop up, you can give a very light watering to soften the crust just as the seedlings are pushing, or gently break the crust with a light tool, taking care not to damage the seedlings. To prevent it next time, avoid a heavy flood right on freshly sown seed and water lightly instead, add organic matter like FYM or compost which is the long term cure for crusting, keep a mulch on the surface, and if the soil is sodic, get it tested because that may need gypsum and a reclamation plan. Sowing into existing moisture and watering gently also avoids the worst crusting. For whether your soil is sodic and needs amendment, confirm with a soil test and your KVK.