SEASONAL DYNAMICS OF ELECTRIC CONDUCTIVITY OF TYPICAL CHERNOZEMS UNDER DIFFERENT SYSTEMS OF AGRICULTURE

Abstract

The influence of different systems of agriculture on the complex of electrophysical (Electrical Conductivity, Total Dissolved Solids, Salinity) and acid-alkaline parameters (pH water, pH salt, hydrolytic acidity) of typical deep mid-loam chernozems on loess during the year (spring, summer, autumn) is studied in the article.Materials and Methods. The study of electrophysical parameters was performed using a conductometer-solemeter (EZODO–8200 M) in soil-water suspensions (1:5). The pH water, pH salt and hydrolytic acid was further determined.The object of study was the typical deep mid-loam chernozem on loess of the Left Bank of the Forest Steppe of Ukraine within the Zinkiv district of Poltava region. The individual soil samples selected in 2018 were analyzed from depths: 0–10, 10–20, 20–30 and 30–40 cm. Variants included: organic farming system (siderate), fallow (over 20 years without tillage), organic farming system (compost), intensive farming system (mineral fertilizers).Results. Established that the electrical indicators of typical chernozem change significantly depending on depth, season and farming systems. The electrical conductivity ranges from a minimum of 21,2 µS/cm in the 30–40 cm layer of the intensive farming system variant to a maximum of 159,3 µS/cm in the 20–30 cm layer of the organic farming system with sidereal steam in the rotation link.Depending on the seasons of the year, the highest electrical conductivity in all variants is observed in the spring and the lowest in the summer. This is directly due to the effects of mineral (NPK) and organic (siderate and compost) fertilizers, as well as herbaceous vegetation in the fallow variant.All investigated variants are characterized by electrical conductivity, which corresponds to the low content of water-soluble salts. At the same time, fallow use promotes a more balanced ion exchange in the 0–10 cm layer, where the highest conductivity values are recorded. The application of organic fertilizers leads to enhanced mineralization processes in the soil and the formation of various salts. This increases the ionization of the soil, which indicates a higher level of conductivity in comparison with the intensive farming system.The correlation analysis shows a strong positive correlation of electrophysical indicators with the pH water and pH salt and a moderate negative – with hydrolytic acidity.Conclusion. The application of organic fertilizers in the form of compost and siderate contributes to better soil ionization, and the use of an intensive farming system leads to a decrease in the level of electrical conductivity.