Concentration of soil CO2 as an indicator of the decalcification rate after liming treatment

This paper presents the results of investigation of decalcification of acid sandy and loamy sand soils by infiltration waters, and potential Ca-leaching after liming treatment. For this purpose, monthly measurements were made of the concentration of CO in the soil air, dissolved inorganic carbon in the soil waters, and their ionic composition. The determined dissolved inorganic carbon ranged from 5.9 to 10.6 mg dm and from 9.9 to 16.5 mg dm for the sandy and loamy sand soil, respectively. The Ca concentration in soil waters was determined as 5.9-12.4 mg dm in sandy soil and 14.2-19.8 mg dm in soil loamy sand. The calculated rate of decalcification amounted to 23.0 kg ha year in soil sandy and 19.4 kg ha year in loamy sand soil. The potential Ca-leaching is predicted as 124 kg ha year for S and 87 kg ha year for loamy sand soil. At the treatment level of 3 000 kg ha 4 year of CaO, ~20% of the Ca-fertilizer can be leached after the liming treatment. The results of the CO concentration in the soil air may be useful in estimation of Ca-leaching from soils developed by slightly clayey sands and clayey sands in zones with a moderate climate.