Statistical assessment of certain properties of soil under permanent grasslands

Geobotanical studies comprised soil and permanent grasslands in the valley of the Por River. The paper describes an assessment of the content of organic matter, reaction (pH) and availability of P, K and Mg in meadow soils overgrown with plant communities classified within the following syntaxonomic units: associations Phragmition and Magnocaricion, orders Molinietalia and Arrhenatheretalia, classes Scheuchzerio-Caricetea nigrae and the order Trifolio fragiferae-Agrostietalia stoloniferae. The results of chemical analyses were confronted with the limit ordinals after IUNG in Puławy (1990) and submitted to statistical analysis using the system of SAS 9.2 from Enterprise Guide 4.2. The analyzed habitats of permanent grasslands had neutral reaction and were dominated by organic soils. Mineral soils occurred in a small area. Generally, a very high or high availability of assimilable P, a low or very low availability of K and a differentiated content of Mg were found in organic soils. In mineral soils, on the other hand, a very high content of P and Mg and a very low content of K were observed. Comparative analyses of selected properties of the habitats showed very significant diversity. Variability coefficients were generally characterized by high values, which points to considerable differentiation of the analyzed properties of the soils within the distinguished syntaxonomic units. Based on our analysis of the Pearson’s correlation coefficients, a number of relations, both positive and negative ones, can be noticed between the properties studied.