We have been applying liquid biostimulants to seeds for a few years now. We have found that for cereal grains like wheat, rye, oats, ect that 8-10 liters of liquid is about all they will take. We have made a second pass of 8 liters after it dried to trial the effectiveness, but didn’t see any response above our usual rates. We always let the grain sit for about a half hour after applying the liquid and then move it again. That seems to help with the clumping issue. For peas, beans, and lentils type seeds we go 5-6 liters max per pass.