Soil Respiration of the Spruce Forest during Four Years after the Application of the Different Dolomitic Limestone Dosage

The study focuses on an in situ response of soil respiration at 10 degrees C (R-10) of the Norway spruce monoculture to the application of the different dolomitic limestone dosages (0; 2; 3; 4; 6; 9 a 26 t.ha(-1)) over a period of four years. Soil respiration was measured within the growing seasons 2016 - 2019. Moreover, the pH was determined in the H and Ah horizons during each season. The effect of liming on soil respiration was statistically significant during all the seasons except for 2017. The greatest effect was observed within the first season after liming. In May 2016, R-10 in the limed plots increased as much as by 97% compared to the non-limed ones. However, soil respiration did not increase in the direct proportion to the liming intensity. We found out the correlation between soil respiration and the micrometeorological parameters (temperature and moisture) when both low temperature moisture limited soil respiration. Due to the strong soil buffering capacity, the small effect of liming on the soil acidity was observed in the first study season. In the following seasons, the differences in the pH among the plots with the different liming intensity started to increase, which was, however, observed only in the H horizon. The substantial increase in the soil microbial activity accompanied with faster respiration after liming can lead to the increased threat of rapid mineralization and the loss of soil organic matter with all its negative impacts.