A process for obtaining pure melamine comprises recrystallizing commercially produced melamine from water. Also disclosed is a composition for synergistically enhancing the growth of plants when applied to the soil around the plants, the composition consisting essentially of a controlled release form of 2,4-dichlorophenoxyacetic acid (herbicide) in conjunction with recrystallized melamine from which the phytotoxic impurities have been removed.
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