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(38-13) Comparison of NOx emission of soil applying KNO3 and (NH4)2SO4 fertilizers. Bálint, Ágnes*,1, Nótás, Erika1, Heltai, György1, Tarr, Zsuzsanna1, Jung, Klaus2, 1 Department of Chemistry and Biochemistry, Szent István University, Gödöllő, Hungary2 Department of Chemical Ecotoxicology, Centre for Environmental Research, Leipzig-Halle Ltd., Leipzig, Germany ABSTRACT- The mobilization and immobilization processes of (15NH4)2SO4 and K15NO3 fertilizers were studied in a laboratory soil core incubation model experiment. Rust-brown soil was filled into 10 cm high plastic tubes and incubated for 30 days at 27 oC at different moisture levels (25%, 50%, 75% water-holding capacity). The soil columns were sampled on the 0,5; 1; 2; 3; 6; 8; 10; 20 and 30th days of the whole incubation period. Different N-forms of 0.01 M CaCl2 extractable NH4+ and NO3- as well as mineralizable and total nitrogen were determined. From the 15N/14N isotopic ratio measurements the recovery percent of fertilizer-N in different N-forms was calculated. As directly the gaseous N losses were not measured that is was the 15N content in total N was used for getting information about the losses by differential method. In this case the 15N content was measured by MS and opposite to the NH4+ and NO3- as well as mineralizable by NOI 7 (ES). In the first twelve hours was found the highest amount of NOx emission. If potassium nitrate was used, than gaseous emission from fertilizer-N was significantly higher, than in case of ammonium nitrate. Acknowledgement. This work was supported by the Hungarian Scientific Research Foundation (OTKA 14983 and 24146 projects) and Hungarian Science and Technology Foundation (project D-9/00). We would like to thank Mrs. Kiss for her hard work. Key words: NOx enission, nitrogen-15, soil incubation |
