A sustained controlled release formulation of soil nitrogen based on nitrate-layered double hydroxide nanoparticle material

Purpose: Nitrate-layered double hydroxide material (nitrate-LDH) matrix can be considered as a potential formulation of delivering nitrogen into soil in a sustained manner. Materials and methods: The nitrate-LDH matrix was formulated by a co-precipitation technique and subsequently characterized by scanning electron microscopy, X-ray analysis, and infrared spectroscopy. The release of nitrate was monitored in different buffer mediums: buffer A as a simulated acidic soil solution and buffer B as a simulated neutral soil solution. Results and discussion: The stability of nitrate-LDH against thermal decomposition was evaluated by thermal gravimetric analysis. The nitrate-LDH supported a sustained controlled release process of nitrate during 16 days into acidic soil at 15 °C, while the release was continued to 20 days into neutral soil at the same temperature. The increase of soil temperature slightly enhanced the release of nitrate. Conclusions: We offered a potential management strategy of soil nitrogen leaching process. The nitrate form of layered double hydroxide material was used as a nitrogen fertilizer in order to monitor the release of nitrate anion into soil at different conditions.