A Novel High Temperature Resistant and Multifunctional Nitrification Inhibitor: Synthesis, Characterization, and Application

The industrialized nitrification inhibitors are not suitable for compound fertilizer fabrication through high tower melt granulation process due to their poor resistance to high temperature. In this paper, a novel high temperature resistant and multifunctional nitrification inhibitor (HTRMFNI) was synthesized. The HTRMFNI is a polymer product with the complex of silicic acid and 3,4-dimethylpyrazole (DMPZ) wrapped inside the polymer and the effective content of DMPZ is 0.484 wt %. The HTRMFNI presents good nitrification inhibitory performance and rapid phosphate-solubilizing ability. The decomposition temperature of HTRMFNI is ∼212 °C, satisfying the temperature requirements for the high tower melt granulation process. The fabricated compound fertilizer presents good nitrogen immobilization performance but loses the phosphate-solubilizing ability, possibly due to the damages of carboxyl functional group on the wrapping polymer by the high melting temperature. Moreover, the addition of HTRMFNI did not affect the physicochemical properties and the overall performance of the compound fertilizer.