RELATIONSHIP BETWEEN SOIL BULK DENSITY, ELECTRICAL CONDUCTIVITY AND POSSIBILITIES OF ECOLOGICAL DIAGNOSTICS
Keywords:
soil grounding, electrical conductivity, environmental diagnostics, compaction, porosity, soil degradation, monitoring, agroecosystemsAbstract
The article explores the relationship between soil bulk density and electrical conductivity as a tool for ecological diagnostics of structural changes. Soil is a key ecosystem component whose functionality largely depends on its structure, density, and moisture content. Intensive use of heavy agricultural machinery leads to soil compaction, reduced porosity, and structural degradation, which in turn affects water infiltration, gas exchange, and biological activity. Experimental studies were carried out on three soil types of the Kura-Araz lowland: meadow-gray, gray-meadow, and alluvial-meadow soils. Electrical conductivity was measured in the frequency range of 0.4–10 MHz under different moisture levels (10–24 %) and densities (1.1–1.4 g/cm³). The results showed a strong linear relationship between electrical conductivity and soil bulk density, which became more pronounced with increasing moisture content. The highest electrical conductivity values were recorded in alluvial–meadow soils, while the greatest sensitivity to compaction was observed in gray-meadow soils. Correlation analysis revealed strong positive relationships (r = 0.95–0.99), and the regression models demonstrated a coefficient of determination R² > 0.90. These findings confirm that electrical conductivity can be considered an integral indicator of soil condition, reflecting the combined effects of physical and hydrothermal parameters. The application of electrical conductivity provides opportunities for early diagnosis of soil degradation, optimization of agricultural practices, and the development of ecological monitoring systems. Moreover, this methodology can be integrated into precision agriculture and applied in interregional comparisons, offering a reliable scientific basis for sustainable land-use strategies.
References
- Brady NC, & Weil RR. The nature and properties of soils (15th edition). Pearson Education [Internet, cited 2016 August 15]. 2016, 912 p. Available from: https://www.pearson.com/en-us/subject-catalog/p/the-nature-and-properties-of-soils/P200000006281/
- Keesstra SD, Bouma J, Wallinga J, Tittonell P, Smith P, Cerdà A, Montanarella L. The significance of soils and soil science towards realization of the United Nations Sustainable Development Goals (SDGs). Soil. 2016;2(2);111–128.https://doi.org/10.5194/soil-2-111-2016
- Lal R. Soil Science Beyond Soil. Soil Science Society of America Journal. 2020;84(3):656–672. https://doi.org/10.1002/saj2.20020
- Corwin DL, Lesch SM. Apparent soil electrical conductivity measurements in agriculture. Computers and Electronics in Agriculture.2005;46(1–3):11–43. DOI: 10.1016/j.compag.2004.10.005.
- Friedman SP. Soil properties influencing apparent electrical conductivity: a review. Computers and Electronics in Agriculture. 2005;46(1–3):45–70. DOI: 10.1016/j.compag.2004.11.001.
- Jacobsen OH, Schjønning P. Electrical conductivity of soils as influenced by soil texture and water content. European Journal of Soil Science. 1993;44(4):593–603. DOI: 10.1111/j.1365-2389.1993.tb00476.x.
- Nadler A, Frenkel H. Determination of soil solution electrical conductivity from bulk soil electrical conductivity measurements by the four-electrode method. Soil Science Society of America Journal. 1980;44(6):1216–1221. DOI: 10.2136/sssaj1980.03615995004400060015x.
- Naderi-Boldaji M, Keller T. Degree of soil compactness is highly correlated with soil physical functions. Soil and Tillage Research. 2016;159:41–46. DOI: 10.1016/j.still.2016.01.010.
- Pozdnyakov AI, Gyulaliyev CG. Elektrofizicheskie svoistva nekotorykh pochv [Electrophysical properties of some soils]. Moscow, Baku: Adilogly; 2004. 240 p. Russian.
- Rhoades JD, Raats PAC, Prather RJ. Effects of liquid-phase electrical conductivity, water content, and surface conductivity on bulk soil electrical conductivity. Soil Science Society of America Journal. 1976;40(5):651–655. DOI: 10.2136/sssaj1976.03615995004000050017x.
- Robinson DA, Jones SB, Wraith JM, Or D, Friedman SP. A review of advances in dielectric and electrical conductivity measurement in soils using time domain reflectometry. Vadose Zone Journal. 2003;2(4):444–475. DOI: 10.2136/vzj2003.4440.
- Zhang X, Hartemink AE. Soil density and electrical conductivity relationships under intensive agriculture. Geoderma.2020;370:114366. DOI: 10.1016/j.geoderma.2020.114366.
- Vashukevich NV, Gyulaliyev CG, Kuklina SL. Diagnostika pochv zony ekologicheskogo monitoringa ozera Baikal s ispol’zovaniem elektrofizicheskogo metoda [Diagnosis of soils in the environmental monitoring zone of Lake Baikal using an electrophysical method]. Agrarny vestnik Urala [Agrarian Bulletin of the Urals]. 2017;2:14–19. Russian.
