Using multi-frequency electrical conductivity measurement to determine the selective salinity in a two-component salt solution

J. Horváth¹*, L. Kátai², I. Czinkota³ and I. Szabó²

¹Hungarian University of Agriculture and Life Sciences, Doctoral School of Mechanical Engineering, Páter Károly utca 1, HU-2100 Gödöllő, Hungary
²Hungarian University of Agriculture and Life Sciences, Institute of Technology,
Páter Károly utca 1, HU-2100 Gödöllő, Hungary
³Hungarian University of Agriculture and Life Sciences,Institute of Environmental Science, Páter Károly utca 1, HU-2100 Gödöllő, Hungary
*Correspondence: Horvath.Janos.7@phd.uni-mate.hu

Abstract:

Digital technologies can help farmers produce safe, sustainable, high-quality food while contributing to the fight against effects of abiotic and edaphic factors. Due to digitalization, a paradigm shift occurred in agriculture, which boosted sensor technology’s rapid development, especially soil sensors. Using sensors and the digital knowledge of soil properties, farmers can better understand the needs of the fields and cultivated plants on a micro-scale, thereby saving resources and putting less strain on our environment. The relative salinity of our soils is an important aspect because of the impact on production costs and yield. The future of site-specific crop production is moving towards a sensor-based on-the-go measurement approach because obtaining important soil characteristics quickly and cheaply is still one of the biggest challenges in precision agriculture today. Measuring soil electrical conductivity (EC) could offer an opportunity to overcome these limitations if the different salt components of soil could be separated by analytical methods. In our study, we present a calibration model based on conductometry with which the selective potassium and calcium content can be determined in the laboratory under controlled conditions. Solutions containing K⁺ and Ca²⁺ cations in the concentration determined in the experimental model were mixed and measured by changing the frequency of the measuring current. In this study, measurements proved that a mathematical relationship can be used to describe the relationship between the composition and concentration of the two-component solution, the measurement frequency and the conductivity. The potassium (K) and calcium (Ca) content of the solution can be separated from each other, and a regression calibration curve can be recorded, from which the proportion of potassium and calcium in the given solution can be determined as a function.

Key words:

digital agriculture, electrical conductivity, multi-frequency, soil salinity, soil sensor

Development and implementation of data collection technologies for digital mapping of soil electric conductivity

M. Kroulik¹,*, P. Zabransky², J. Holub¹ and J. Chyba¹

¹ Czech University of Life Sciences, Faculty of Engineering, Department of Agricultural Machines. Kamycka 129, CZ165 21 Prague 6 – Suchdol, Czech Republic
² Czech University of Life Sciences, Faculty of Agrobiology, Food and Natural Resources, Department of Agroecology and Biometeorology. Kamycka 129, CZ165 21 Prague 6 – Suchdol, Czech Republic
*Correspondence: kroulik@tf.czu.cz

Abstract:

One of the main preconditions for the introduction of soil protection measures and sustainable use of a soil is to strengthen the knowledge base about the specific habitats characteristics with high spatial resolution and adequate interventions to these properties. One of the most common sensors used to describe the level of soil variability are devices that measure the electric conductivity of the soil.
Platform for the electrical conductivity measuring has been developed and implemented into the standard combined machines for the tillage and seeding, using an existing work tools as part of the platform. Within the field work the series of measurements was conducted with this machine and platform and data of electrical conductivity were collected. On the same field as a reference method electrical conductivity was measured by an electromagnetic induction probe EM38 MK2. Compared data from the measuring platform and the EM38 MK2 probe showed a high correlation value. The experiments demonstrate the possibilities of technical solutions of soil conductivity measurement implementation on tillage and seeding machines where by a modification of selected tillage and seeding machines together with incorporation of sensors directly onto the work tools is possible to obtain measuring platform that enables data collection directly during operation of the machine on the field.

Key words: