Methods of coating seeds with polymers and seeds coated with such polymers are disclosed herein. The polymers can be phosphonates, sulfonates, polymers of ethylenically unsaturated carboxylic acids, polyaminopolyethermethylene phosphonate, polysuccinic oligomers, acrylic acid/2-acrylamido-2-methylpropane sulfonic acid, blends of acrylic acid/2-acrylamido-2-methylpropane sulfonic acid with polyaminopolyethermethylene phosphonate, sulfomethylated acrylic acid/acrylamide, blends of sulfomethylated acrylic acid/acrylamide with polyaminopolyethermethylene phosphonate, polymaleic acid, acrylic acid/acrylamide copolymers, polyacrylic acid, trimethylglycine hydrochloride, blends of polyaminopolyethermethylene phosphonate with trimethylglycine hydrochloride, and any combination or salt of such polymers. Methods of monitoring, determining, and controlling the concentration of scale inhibitors in an agricultural irrigation system are also disclosed herein.