Torma S.

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. The study of changes in the main agrochemical parameters in the upper layers of the gray forest soils of the Left Bank Forest-Steppe of Ukraine that were removed from agricultural processing and forested with pine, in different years. Methods. Theoretical methods included the collection and description of facts, their analysis. Empirical methods involved conducting field research on test plots of the state-owned enterprise “Chu-guevo-Babchansky LG” and farm near woodlands. Laboratory and analytical studies were performed using standardized measurement methods. The generalization of the experimental data was performed using applica-tion software packages. Results. Studies were carried out on soils under natural forest plantations, soils in inten-sive agricultural processing and unproductive soils that are derived from agricultural use. In all the studied soils, the main agrochemical parameters were compared among themselves: mobile forms of nitrogen, pH, humus content, content of common forms of nitrogen, phosphorus and potassium. Statistical dependences between agrochemical parameters in the studied variants were established. Conclusions. The results obtained indicate the revitalization and development of humification and accumulation of nutrients in old arable gray forest soils with an increase in the duration of exposure to pine forest. The age stages of the forest determine the specifics of the environmental factors that influence the soil-forming processes. In the soil of a young pine-tree (12 years), there are more cases of an increase in the coefficients of spatial variation. This indicates that the formation of young ecosystems are characterized by low resistance, in these biocenoses the dynamic equilibrium is not reached, which is characteristic of more mature pine forests.

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.

In consequence of the mining and processing of the magnesite ore, some areas of Slovakia have strongly damaged soil, when pH increased to 9 and more. The physical and chemical characteristics of the soil were changed, the erosion increased and phytocenosis decreased. A large number of the soils is impossible to use for agriculture. The fertilization requires huge resources. The future for the fertilization and prospective use of the soils is seen in the possible cultivation of Phragmites australis, which was selected in given area. It is an invasive plant with the possible technical and agricultural use. The use of Phragmites australis against strongly alkalized soils was suggested by previous investigation, as it grows also on the soils with pH 9.1 and produces very large biomass. Thence during three years the most suitable method of the reproduction of this plant was investigated, i.e. generatively and vegetatively. On the basis of the statistical evaluation of the results it can be concluded that generative reproduction is technically more demanding and less successful, that the vegetative root segment reproduction is more suitable and can be recommended under these conditions.

The change of basic agrochemical soil properties in a farm with ecological system of farming («Liptovska Teplicka») during three years period was observed. It was found that with high rates of farmyard manure (60 t per ha) there is possible to keep the favourable pH value of soil and also the contents of available nutrients did not change very markedly. Triticale was found as the most suitable cereal in given climatic conditions. It is important to grow leguminous plants to secure relatively high yield of fodder plants. There is possible to reach the stability of agroecosystem with the biodiversity of farming area and with return of organic matter into the soil.