The On-the-Go Soil PH sensor is a device that allows the measurement of soil pH levels on-site. It uses a novel solid reference electrode made of Antimony as a sensing electrode. It also has the ability to be submerged in the soil for an extended period of time.
On-the-Go Soil PH sensor
The On-the-Go soil PH sensor is designed to provide soil pH measurements on-the-go. The sensor is calibrated using reference samples. The calibration was successful using ten soil samples. The sensor had improved calibration accuracy in a field with a large texture variation. It recorded mean absolute errors of 0.28 to 0.40 pH units. However, the sensor has some limitations, including blocking by soil residues and weed roots.
During a field study in Germany, the On-the-Go soil pH sensor was used to map soil pH. The results were compared to standard soil pH maps, which revealed a linear correlation. The study also demonstrated the need for calibration to reduce errors when predicting soil pH. This is important because soil pH differences of as little as 0.1 units can affect the amount of lime recommended for a field.
Antimony as the sensing electrode
The antimony as sensing electrode can be used in soil PH sensors to detect changes in soil pH. The antimony electrode can be made of pure antimony or Sb(+III) oxide. Pure antimony is preferable because it enhances the characteristics of the electrode, such as reproducibility and stable electrode potential over long periods of time. Casting the electrode requires melting the antimony and sucking it into a glass capillary. The electrode is then cooled to solidify. Slowly cooled electrodes have better response than those rapidly cooled. In addition, oxygen must be excluded during casting to avoid formation of oxides.
In a study that used soil samples with pHs of four and seven, researchers found that the antimony electrodes had a memory effect. This means that pH readings in subsequent samples increased or decreased slowly depending on the pH of the previous sample. This is problematic because the antimony electrodes do not capture the entire range of pH values in soil. Consequently, they will underestimate the pH of soil when it is changing rapidly.
Novel solid reference electrode
Several factors influence the performance of a soil PH sensor, including the stability of the reference electrode. One method is to assemble the electrode using a polyelectrolyte and nanoporous Pt assembly. This method produced a stable open-circuit potential for a constant pH. This assembly was found to have exceptional potentiometric properties, including excellent reproducibility (n = 5), and long-term stability (>1 mV) for up to 50 h. Furthermore, it exhibited high stability and was independent of both pH and ionic strength.
This method was carried out using an electrochemical workstation. The electrodes were connected to the working and reference electrical lines. The working electrode was a thin-film gold electrode, while the reference electrode was a Pt wire. The electrodes were then inserted in a lugging capillary containing saturated K2SO4 and KCl 3 M. Various pH measurements were conducted on the electrodes, and their responses were compared.
Response time analysis
Response time analysis of soil PH sensor results reveal that soil pH sensors can be used to measure soil pH. In this study, we analyzed soil pH sensors under various conditions, including controlled laboratory tests, semi-controlled field tests, and practical on-the-go scenarios. We compared the results to standard laboratory calibrations to evaluate their accuracy.
The results of the study suggest that soil pH sensors perform reasonably well in areas with low pH levels. The on-the-go mapping technique improved the accuracy of soil pH measurements compared to standard maps and reduced error in the estimation of lime requirement. This approach can reduce the cost and time required for conventional laboratory analyses.
Compared to the five-probe sensor, the 4-probe sensor has a higher sensitivity but a lower detection limit. It also has a smaller range of parameters.
Effects of temperature
Temperature plays an important role in many physical, hydrological, and biogeochemical processes in soil. It also exhibits considerable spatiotemporal variability. Soil temperature measurements can be made at small and large scales, using a variety of sensors. One of the easiest ways to measure soil temperature is by remote sensing, which relies on the reflectance properties of the earth’s surface.
Temperature changes have an effect on several soil parameters, including plant growth, organic matter content, and the amount of living biota. The temperature of a soil directly controls its water content and directs changes to other soil parameters. This information is important for predicting soil conditions and suitability for growing plants.