FERTILIZERS' LEACHING FROM THE ROOT SYSTEM ZONE - A POTENTIAL ENVIRONMENTAL RISK FOR GROUNDWATER POLLUTION IN COARSE AND MEDIUM-TEXTURED SOILS

The objectives of the paper are to test if the nitrogen (mineral and organic), phosphorous and potassium fertilizers commonly used in field crops penetrate deep into the soils, and find out their leaching characteristics in the case of different-textured soils, in order to assess the potential environmental risk and recommend measures for limiting such losses. Three soil types were studied in undisturbed microlysimeters: sandy-textured Eutric Arenosol, AR-eu, loamy-textured Haplic Chernozem, CH-ha, and clayey-textured, swell-shrink Luvic-Chernic Phaeozem, PH-ch-lv. Two fertilizer applications containing amide N, as well as P2O5 and K2O were applied. Then distilled water was applied daily according to the infiltration rate simulating a wet season, and the effluent was collected. Soil texture and soil hydraulic properties determined the pattern of effluent concentration for all chemicals. K leaching losses from the root system zone of the soils presented the highest means, followed by N losses, while the lowest losses were found for P. Significant differences between the soils were found. Because various soil textures were studied with this experiment, the results might be used in similar environments from many countries. If global warming with extreme rain events continues, then fertilizer leaching losses could increase. To minimize nutrient leaching losses some measures are recommended. Further research should be focused on larger soil-texture diversity and cropped soils.