Nano-Zeolite Amendment to Minimize Greenhouse Gas Emission in Rice Soil

A greenhouse study was undertaken to determine nitrogen dynamics and greenhouse gas (GHG) emissions in rice soils amended with nano-zeolite based nitrogenous fertilizer application. It is hypothesised that nano-fertilizer carrying N regulates the release of N in rice soils that minimizes greenhouse gas emission while improving the availability of N in judicious combination. Nano-fertilizer carrying NO^3- or NH⁴⁺ forms of nitrogen were synthesized using commercial nano-zeolite by fortifying two forms of N. The nano-zeolite was characterized before and after loading N. Nitrogen release pattern of synthesized nano-fertilizers (nitrate and ammonical forms) was studied in a percolation reactor. The data have shown that N release from the nano-fertilizer (NH⁴⁺ form) and conventional fertilizer (ammonium sulphate) were 480 and 310hrs, respectively. On the other hand, the N release from nano-fertilizer (NO^3- form) and conventional (potassium nitrate) were 280 and 210 hrs, respectively. This suggests that both forms of nano-fertilizer release N slowly and steadily for an extended period of time. Soil fertilized with nano-fertilizer (NH⁴⁺ - N) recorded lower N₂O emission (1.8 mg m^-2 day^-1) than conventional fertilizer (2.7 mg m-2 day-1). On the other hand, soil fertilized with nano-fertilizer (NO^3- - N) registered lower CH₄ flux (34.8 mg m^-2 day^-1) than conventional fertilizer (36.8 mg m^-2 day^-1). These data suggest that the nano-fertilizer regulates the release of N that closely coincided with the benefit of reduction in GHG emission.