Dendritic polyurea microcapsule: a slow release nitrogenous fertilizer

Nitrogen use efficiency of urea fertilizer is very low for various crops and very large proportions of the fertilizer nitrogen are lost from the crop field through ammonium volatilization, nitrification and de-nitrification, and nitrate leaching. Therefore, to reduce nitrogen losses and the adverse effect of nitrogenous fertilizer on the environment a slow release of highly efficient polyurea microcapsule nitrogenous fertilizer is developed for prolonging release of nitrogen in soil. In this context, neem seed oil encapsulated polyurea microcapsule is developed by interfacial polymerization approach. Polyurea microcapsule contains 68.98% carbon, 11.31% hydrogen and 5.95% nitrogen. The mean particle size of the synthesized polyurea microcapsule was 2.137 µm. The synthesized 0.5 G, 0.0 G dendrimer and polyurea microcapsule were characterized by Fourier transform infrared spectroscopy. Disappearance and appearance of peak at 2841.76 cm−1 and 1745.94 cm−1 confirmed the synthesis of 0.0 G PAMAM and amide bond formation in polyurea microcapsule, respectively. The stability of polyurea microcapsule was confirmed by thermogravimetric analysis. Results of incubation study showed that sustained release of NH4+–N and NO3−–N from polyurea microcapsule under field capacity as well as under submerged condition. Hence, polyurea microcapsule could be a suitable option in as a source of nitrogen for crops under field condition.