Лисняк А.

Soil investigation oriented to soil reaction study took place in two agricultural farms in 2004 and it was repeated after four years again. The pH value change at total absence of liming was balanced. It was confirmed that liming ab-sence resulted in soil reaction rapid decrease in natural way - by calcium and magnesium resorption with crops, their leaching into deeper soil horizons, their outflow with erosion but also physiologically acid fertilization. In the agricul-tural enterprise Nemsova neutral and alkaline soil acreage (pH value above 6.6) decreased from 1008 ha to 190 ha in period 2004-2008 (decrease 82 per cent) and contrary soil acreage with pH value below 5.5 increased from 274 ha to 569 ha in the same period. There is even more unbeneficial situation in the agricultural farm Osikov. Acreage with pH value above 6.6 was reduced in period 2004-2008 from 1548 ha to 178 ha (decrease 90 per cent), while acid and strong acid soils (pH lower than 5.5) increased from 138 ha to 838 ha in the same period.

Purpose. To differentiate rural land of Slovakia with aspect to the possibility of effective spring barley growing. Methods. Soil investigation oriented to soil reaction study took place in two agricultural enterprises in 2010 and it was repeated after four years again. Results. At soil categorization, correlation relationships between the site properties (soil and climatic conditions) and crop biological and agrotechnical requirements were considered. Spring barley requirements were included into yield databases using the software filters in the way that the given site property excluded or limited barley growing, what was reflected in predicted production. The prediction was subsequently interpolated into four suitability categories: soils not suitable for spring barley growing, less suitable soils, suitable soils and very suitable soils. The database formed and each of the Bonited Pedo-Ecological Unit (BPEU) was added in it as well as particular category of suitability for barley growing. By mediation of the Geographic Information System on BPEU distribution in Slovakia, the map of categories of soil suitability for spring barley growing was also generated. Conclusions. In Slovakia, there is 20 % of farmland very suitable for spring barley growing, 24 % suitable, 24 % less suitable and 32 % non suitable soils for spring barley growing according to our calculation. In the paper, these categories are characterized in details and specified from the view of geographic, soil, climatic, productivity, economic and energetic parameters.