PENENTUAN KADAR UREA MENGGUNAKAN SOIL SENSOR BERBASIS IMPEDANSI SPEKTROSKOPI

Abstract

Determination of urea concentration in soil sample using soil sensor has been carried out. Determination of urea content is very important to do to increase the efficiency of fertilization in the agricultural sector, but until now farmers rarely analyze urea levels because of its high cost, besides that the instruments used are also very limited. Therefore, in this study a characterization was carried out to develop a multi sensor for the manufacturing of instruments that capable of determining urea levels in the soil. The sample used in this experiment was the inceptisol soil, which added with urea for varying concentrations. The characterization was done by measuring the impedance value using two electrodes made of stainless with a length of 20 cm and a diameter of 0.8 cm, embedded in soil sample and DAQ Card NI PCI 6221, which is controlled by the LabVIEW application by comparing the values of V(I) and V, thus obtained absolute impedance, real resistance, imaginary resistance and reactance value. The result graphs show that the impedance value of the soil decreased and the sample is more conductive as the urea concentration increased. The measurement results also show that reactance of the sample was capacitive, the reactance value decreased with increasing urea concentration and decrease due to the increased frequency. From the result of this research, urea concentration in soil sample at different frequencies can be determined that are 10Hz, 100 Hz, and 1 kHz.