Soda production (Na2CO3) in the plant Janiko-Soda SA, in the region Kujawy, generates large amounts of waste deposited in sedimentation tanks near the factory. The impact of soil salinization caused by the waste on the magnesium status in nearby soils, classified to Gleyic Phaeozems, was studied. Soil samples were collected from 9 representative sites from two depths: 0-20 cm and 20-40 cm. Samples differed in soil salinity, expressed by electrical conductivity, which was in the range of 0.75-43.91 dS∙m-1. Exchangeable, plant available and total magnesium as well as exchangeable cations: Ca2+, K+, Na+ were determined. Moreover, the concentration of Cl- ions was also determined. For the characterization of the properties of soil material, the organic matter content and pH in H2O and 1M KCl were evaluated. The content of chlorides varied in a wide range: from 18.0 mg·kg-1 up to 19 570.0 mg·kg-1. It was observed that available and total magnesium content was comparable to the content of this element in soils beyond the impact of soda waste. Negative changes were mainly extended to exchangeable forms of magnesium. Calcium was the dominant cation and an extremely low proportion of Mg was present in exchangeable sites in the studied soils. The concentration of Ca2+ exceeded the Mg2+ concentration by one to two orders of magnitiude. The exchangeable magnesium content decreased with an increasing soil salinity level, measured by electrical conductivity. Excess of exchangeable sodium ions was also observed in soil samples taken from the vicinity of sedimentation tanks filled with soda waste. Calcium, sodium and chloride content was statistically correlated with electrical conductivity of the soil extract (r = 0.933, r = 0.961, r = 0.984, respectively).

23.1.2018