Soil Agrochemical Changes after Kieserite Application into Chernozem and its Effect on Yields of Barley Biomass

A two-year pot experiment (5 kg of soil - Mitscherlich pots) was established in a vegetation hall in Brno (Czech Republic) in the years 2016‒2017. Spring barley, variety KWS Irina, was grown. Chernozem from Brno (with a good magnesium (Mg) content and alkali soil reaction - 7.37) was used for this experiment. The rates of Mg (0.075-0.15-0.3 g per pot) and sulphur (S) (0.1-0.2-0.4 g per pot) were increased by using the ESTA Kieserite fertiliser (25% MgO; 20% S), treatments 2-4. Nitrogen was applied in the form of Calcium Ammonium Nitrate - CAN (27% N) at a rate of 1 g N per pot in all the treatments including the control. The effect of the year was found to be significant on all the parameters under study, with the exception of the soil reaction. The exchangeable soil reaction (pH) after the harvest did not differ in all the fertilised treatments (7.40-7.50) compared to the unfertilised control treatment (7.40-7.45) in both years. The content of post-harvest soil Mg and S increased significantly with the applied rate (285-354 mg Mg/kg in fertilised treatments compared to 276-284 mg Mg/kg in unfertilised control and 47-112 mg S/kg in fertilised treatments compared to 24-54 mg S/kg in unfertilised control, respectively). Dry matter yields of the aboveground biomass were significantly the lowest in the control treatment not fertilised with Mg and S during both years (23.00 and 29.02 g DM per pot) and increased after applications of Mg and S: 27.75-29.25-28.25 in 2016 and 30.33-31.00-34.50 in 2017 (g DM per pot).