Mineralisasi nitrogen pada tanah tukungan dengan umur yang berbeda

Abstract

The research conducted in the laboratory aimed to determine nitrogen mineralization in different ages of raised-bed soils. Raised-bed soils of different ages: 2, 8, 15 and 26 years were incubated in the laboratory at 70% water-filled pore space (WFPS) for 30, 60 and 90 days, and the measurements of NH4+ and NO3- were carried out at the end of each incubation period. Results of the experiment showed that at the incubation periods of 60 and 90 days, the concentration of ammonium in raised-bed soils with ages 2 and 8 years was higher than the raised-bed soilsaged 15 and 26 years. In contrast, nitrate contents in the raised-bed soils with ages 2 and 8 years is always lower than the raised-bed soils with ages 15 and 26 years at all incubation periods. Nitrate content is about 2 times higher than the ammonium contents in all measurements, so that the total available nitrogen content (NH4++NO3-) is higher in older raised-bed soils at all incubation periods. The results of this study show that nitrogen availability through the mineralization process is determined by the age of raised-bed soils.