Abstract:
The overuse of nitrogen fertilizers, most frequently urea, has been identified as a major
source of radiative nitrogen (Nr), which is responsible for catastrophic environmental
effects owing to leaching, volatilization, and N2O emission from fertilized croplands.
It has long been recognized that biochar may help increase the effectiveness of how
well crops utilize nitrogen in improved areas. In this study, granular biochar
composites were obtained by blending urea with cassava stem biochar supplemented
with the clay mineral bentonite. These biochar composites were first characterized by
microscopic analysis with FTIR and SEM, and then tested for N leaching in water in
a column experiment and the growth of okra plants in pot culture compared with urea
fertilizer. FTIR analysis indicated strong functional groups in the unmodified biochar
and chemically modified biochar. Nitrogen release was decreased by 12.6% in urea
fertilizer and 9% in the BC-60 biochar composite during a 30-day leaching experiment.
According to this, nitrogen was released from the BC-60 composite at a much slower
rate when urea fertilizer and biochar composites were compared. In pot culture with
okra growing, total plant height was enhanced by 18 cm and root height by 4.5 cm
under BC-60 biochar composite compared to UF. Furthermore, compared to urea
treatments, BC-60 composite has significantly higher plant parameters. This study
suggested that N in the biochar composites was shown slow release in water and okra
growth promoting in soil, relative to conventional urea. As a result, biochar made from
agricultural waste might be used to mix urea and substitute mineral urea, hence
reducing N usage and its effect on global Nr levels.
