Urea modified calcium carbonate nanohybrids as a next generation fertilizer

Abstract

With increasing world population, sustaining food security of people has become a daunting challenge. Scientists have explored various pathways to feed the global population. One way is the development of efficient nutrient and pest control systems together with improved crop varieties. Most of the conventional fertilizer systems in practice have not met the plant nutrient requirements basically due to the low Nitrogen Use Efficiency (NUE) of plants. There had been many attempts to develop efficient fertilizer systems particularly to supply nitrogen, which is the major nutrient needed for plant growth. Urea, being an excellent candidate for nitrogen fertilizer, it’s efficient and targeted delivery is a must. This research focuses on the synthesis of scalable, cost-effective and efficient nitrogen fertilizer, which retards the solubility of nitrogen at a minimum of 5 times compared to pure urea. Being a bioinspired material, calcium carbonate (CC) renders added advantages of biocompatibility and non-toxicity. Urea-CC nanohybrid was synthesized using an in-situ rapid carbonation method which resulted in cubic platelike nanoparticles which are stacked together to form pine cone-like structures. The Fourier transform infrared spectroscopic data provides conclusive evidence for bonding interactions of urea with CC nanoparticles giving a platform for controlled release properties of urea. Crystallographic data of nanohybrids were obtained from powder X-ray diffraction. Nitrogen release behaviour of the novel nanohybrids exhibited controlled release properties over pure urea demonstrating that the urea modified CC nanocomposites introduced herein have the potential to replace the conventional fertilizer systems to sustain future food security.