EFFECT OF SOIL DEPTH ON REACTION RATE OF NITRIFICATION PROCESS IN SOIL

• Main Author: Thanthawi, Imam
• Format: Theses
• Language: Indonesia
• Subjects: Teknik saniter dan perkotaan; teknik perlindungan lingkungan
• Online Access: https://digilib.itb.ac.id/gdl/view/35222
• Institution: Institut Teknologi Bandung

Nitrogen is one of the amino acid forming compounds in living things, both plants and animals. Plants get nitrogen from the soil through an assimilation process. Today, the content of inorganic nitrogen or nutrients for plants in the soil is very limited, while food demand is increasing. Therefore, the use of synthetic fertilizers is considered important to meet nutrient deficiencies in the soil. However, continuous use eventually causes problems for the environment, both in the air, in the water, and in the soil. The study will be conducted is to study the nitrification process in soil with a depth of up to 30 cm. The observation process was carried out on 2 reactors that had been filled with soil and given urea fertilizer with a concentration of 3.88 g and 4.86 g which had been dissolved into 500 ml of aquades and the observations were made at a depth of 1-10 cm, 11-20 cm, and 21 -30 cm for 7 days. The results showed that on the first day after the addition of urea fertilizer, soil pH decreased from 7.13 to 5.4 in reactor I and 5.8 in reactor II. The pH, temperature and water content values were not significantly different, so the decomposition process of urea and nitrification that occurred in the two reactors was considered the same. Urea hydrolysis that occurred resulted in concentrations of NH4+ up to 0.907 ppm on day 5 in reactor I and 1.02 ppm on day 6 of reactor II. In this study, the difference in urea concentration given did not significantly influence the concentration of NH4+. Urea hydrolysis is predicted to continue for several days later. The nitrification process or optimum NO3- formation occurs at the surface of the soil or at a depth of 1-10 cm with a concentration of 0.87 ppm on day 7 in reactor I and 0.763 ppm on day 6 in reactor II. In general, the formation of NH4+ and NO3- increases every day. The theory does not always occur in the soil, because the flow of urea solution given does not enter the soil evenly. This is caused by the porosity and the soil texture which cannot be predicted. The results of data analysis using the reaction kinetics equation states that this study can be explained using the second reaction order equation which is influenced by the depth and concentration of O2 in the soil.