Electrolyte-Tolerant Dispersing Agent for Suspension Concentrate Compatibility with Liquid Fertilizer

Many, if not most, pesticides are not compatible with liquid fertilizers. The goal of the research presented in this paper was to develop a dispersant system that would allow the direct dilution of suspension-based agrochemical formulations into undiluted fertilizer. To evaluate the compatibility of dispersant systems with fertilizer, a series of surrogate fertilizers, based on ammonium phosphate solutions, was used with a variety of ionic strengths and pHs. Baseline performance was established with typical dispersant systems, and then a variety of electrolyte-tolerant surfactant systems was evaluated for improved compatibility performance. The most promising combinations of surfactants were evaluated in commercial fertilizer products of varying N-P-K (nitrogen-phosphorus-potassium) composition, pH, and micronutrients. A blend of surfactants was developed that shows robust compatibility with the set of commercial fertilizer products and compared favorably to a commercially available fertilizer-tolerant suspension.