The Potential of Thiosulfinates in Garlic Extract as Bio-Inhibitor in Urea Fertilizer

Urea is extensively used as fertilizer in the agricultural industry based on its suitability for all types of crops. The hydrolysis of urea fertilizer produces ammonia (NH3) and carbon dioxide (CO2). However, up to 40% of NH3 release affects the efficiency of urea fertilizer. By introducing inhibitors into the urea enzymatic reaction, the NH3 emission problem can be solved. Unfortunately, current inhibitors are usually chemical based and non-biodegradable. Several complaints and accidents have been reported when handling chemical based inhibitors especially for surface application. Research on garlic or Allium savatium has been conducted to ensure its inhibitory effects as potentially safe and biodegradable inhibitor. From previous research, thiosulfinates (TS) contained in garlic extract proved to inhibit platelets aggregation in medical applications. TS is obtained by extracting garlic cloves. In this study, the inhibitory effect is determined by analyzing NH3 concentration in urease-garlic mixture and standard urea assay mixtures using UV-VIS spectrophotometer device. The Beer’s Lambert law is used for calculating the concentration with an aid of the standard NH3 calibration graph. Based on previous research, the NH3 concentration is predicted to decrease with urease-garlic mixture amount and time.