Pedochemical evaluation of soils, characterizing the pastoral localities of the National Nature Reserve Mohelno Serpentine Steppe. I. Physical, physical-chemical and nutritional parameters

The scope of this work is a detailed evaluation of pedochemical parameters and properties of so-called "serpentine soils", which form an essential part of grazing area of The National Nature Reserve Mohelno Serpentinite Steppe. Soil properties directly affect the quality of grrowing biomass of permanent grassland, and subsequently, also animals/consumers (ie. grazing sheep and goats). The soil profiles have been descibed and sampled, thus soil types were classified. According to the Taxonomic Classification System of Soils of the Czech Republic (2011) we classified ranker melanic, with high content of magnesium. Hyperskeletic Leptosol Humic has been classified according to the IUSS WRB (2015). Soils were medium textured in terms of the USDA triangle diagram (Taxonomic Classificationof Soils of the Czech Republic, 2011) and the older Czech classification according to Novák. Due to the specific chemism of serpentinite (serpentine), soil reaction varied from weakly acidic to neutral pH. The high content of different magnesium form was determined, as well as a significant wxcess of biomobile (plant-available) form of magnesium over calcium. Relatively high soil organic matter content, resp. oxidizable carbon in the upper horizons (Cox 4.28-6.75 %) had a balanced (1:1) ratio of humic (HA) and fulvic acids (FA), a color quotient (Q4/6) < 4, and low humification degree (< 20 %). The relatively favorable Cox/Nkjel ratios in the upper horizons (9.6-13) indicates both the quality and stability of humus, ans sufficient content of available nitrogen in soil. Deficiency of biomobile form of phosphorus in serpentine soils according to the soil extract of Mehlich-3 was also confirmed. Despite some general claims, however, the content of plant-available form of potassium was at least sufficient (satisfactory) and did not fall beow this category even in the horizons of the soil-forming substrate. However, the most important criterion is content of macro-elements in both terms of their abundance in above-ground biomass of permanent grassland and their mutual balance in terms of nutritional value for grazing ruminants.