M.S. Brodowska, M. Kurzyna-Szklarek, T. Filipek
University of Life Sciences in Lublin, Department of Agricultural and Environmental Chemistry, Lublin, PL

ESTIMATION OF THE SELECTED CHEMICAL PROPERTIES OF SOIL AGROECOSYSTEMS IN THE ASPECT OF UNBALANCED MINERAL FERTILIZATION


Soils fertility and crop yields are largely determined by the physical, physicochemical and chemical properties of soil. One of the most important features of soil is the sorptive capacity, which is an indicator of the soil's ability to adsorb exchange cations. This property can be used to assess the level of soil trophicity, degree of acidification as well as resistance to chemical degradation. In addition, it has an impact on the efficiency of fertilization, which is very important in plant cultivation, especially in heavily-used agricultural soils, where agrotechnical treatments can influence the rate and direction of changes in the chemical and physical properties of soils. The purpose of the research was to determine the influence of unbalanced mineral fertilization on the soil chemical properties, including the content of exchangeable cations (Ca, Mg, Na, K) and their sum, soil sorptive capacity and saturation of the sorptive complex with basic cations. A four-year, two-factor field experiment was conducted using the split plot method. The soil on which the experiment was founded belonged to the fourth category of agronomic - heavy soil, the second soil quality class and the agricultural suitability - good wheat. Prior to foundation experiment, the soil was slightly acidic (pH = 6.02), total exchangeable cations 62.1 mmol(+)·kg-1 and exchange capacity 81.4 mmol mmol(+)·kg-1. Analysis of the obtained results shows the significant influence of mineral fertilization and meteorological conditions on selected soil quality indicators. Experimental field experiments confirmed the effect of the absence of nitrogen, potassium, magnesium or sulfur on the content of exchangeable cations, soil sorptive capacity or saturation of the sorptive complex with alkaline cations in the soil after harvest of winter oilseed rape, winter wheat, spring barley and sugar beet. Drought periods during the growing seasons and extreme temperatures clearly differentiated the analyzed soil chemical properties.

Keywords: soil, mineral fertilization, exchange capacity, exchangeable cations