Determining The Dense Soil Depth Using Acoustic Wave

Abstract

Determining the dense soil depth using acoustic wave is one of the attempts of non-destructive detection method development. This method is applied since the ultrasonic wave detection has been widely conducted and applied in other fields, besides agriculture. The particular purpose of the research is to determine the amplitude of the acoustic waves received as the bouncing effect or the propagation on soil by the cultivating treatment on the dense soil depth. The research tools and materials applied is a sample soil of Latosol, which is connected through circuit of a series of signal generator used as the sinusoidal signal generator, and processed to transmitter speakers in several frequencies. Op-amp circuit functions as the amplifier and the audio waves stabilizer gained by receiver speakers, and they are connected to oscilloscope to visualize the results. Op-amp circuit with bigger amplified level, equipped with a filter circuit, and uses the appropriate power on the transmitter speakers circuit will cause the intensified waves transmitted according to the expected results. The use of the same kind of speakers eases the research to produce results as needed. The research is conducted at 30 % of water content by the speaker position forming 300 angles with bulk density of 1.0 gram/cm3 and 1.3 gram/cm3 in the cultivation layer of 0, 5, 10, 15, and 20 cm. In the treatment of cultivation layer thickness is known that the denser or thicker cultivation layer the smaller receiver of the audio wave amplitude. In the estimation of the dense soil depth using audio waves, it is seen that the audio wave amplitude value received will be smaller in the increase of cultivated soil layer. The making of the instrument is adjusted with the result of the previous research. The noise influences the sound waves produced and transmitted, and also the amplitude waves received. The noise covers the transmitted sound waves so that the sound waves is not detected by the oscilloscope.