Multi-Channel Optoelectronic Measurement System for Soil Nutrients Analysis

Abstract

To solve the problems that occur when farmers overuse chemical fertilizers, it is necessary to develop rapid and efficient portable measurement systems for the detection and quantification of nitrogen (N), phosphorus (P), and potassium (K) in soil. Challenges arise from the use of currently available portable instruments which only have a few channels, namely measurement and the reference channels. We report on a home-built, multichannel, optoelectronic measurement system with automatically switching light sources for the detection of N, P, K content in soil samples. This optoelectronic measurement system consists of joint LED light sources with peak emission wavelengths of 405 nm, 660 nm, and 515 nm, a photodiode array, a circuit board with a microcontroller unit (MCU), and a liquid-crystal display (LCD) touch screen. The straightforward principle for rapid detection of the extractable nutrients (N, P, K) was well-established, and characterization of the designed measurement system was done. Using this multi-channel measurement system, available nutrients extracted from six soil samples could be measured simultaneously. The absorbance compensation, concentration calibration, and nutrition measurements were performed automatically to achieve high consistency across six channels. The experimental results showed that the cumulative relative standard deviations of 1.22%, 1.27%, and 1.00% were obtained from six channels with known concentrations of standard solutions, respectively. The coefficients of correlation for the detection of extracted nutrients of N, P, K content in soil samples using both the proposed method and conventional lab-based method were 0.9010, 0.9471, and 0.8923, respectively. Experimental results show that this optoelectronic measurement system can perform the measurement of N, P, K contents of six soil samples simultaneously and may be used as an actual tool in determining nutrients in soil samples with an improvement in detection efficiency.

Recent Advances in Biometrics and Its Applications

“…Other related applications that can involve biometrics have been presented in [9][10][11][12][13]. The authors propose interesting detection and recognition approaches with applications in the domain of watermarking [9], health [10][11][12], and nutrients analysis [13]. We found that the ideas of the proposed contributions for data processing, feature extraction, learning, and embedded systems, seem interesting to be considered in the field of biometrics.…”

“…Other related applications that can involve biometrics have been presented in [9][10][11][12][13]. The authors propose interesting detection and recognition approaches with applications in the domain of watermarking [9], health [10][11][12], and nutrients analysis [13].…”

Advanced Multi-functional Sensors for In-situ Soil Parameters for Sustainable Agriculture

“…(continued from previous page) measurements. 10 Based on the Beer-Lambert law, relatively high correlation peaks were obtained between the absorption at the emission wavelength and their respective nutrient concentration in the soil sample. Similarly, Shibusawa employed a multi-sensor system to measure moisture content, soil organic matter, nitrate nitrogen, pH, and electrical conductivity for a field depth of 15-40cm.…”

Minimalizing Non-point Source Pollution Using a Cooperative Ion-Selective Electrode System for Estimating Nitrate Nitrogen in Soil

“…Therefore, it is important to normalize the measurement of -N in soil ( Cho et al, 2018 ; Richa et al, 2021 ). Considering the concentrations of -N in soil is readily influenced by environmental factors and changes rapidly, it is necessary to perform in situ measurement to evaluate the non-point source pollution ( Wang et al, 2015 ; Ma et al, 2019b ).…”