The changes of soil nitrogen and carbon contents in a long-term field experiment under different systems of nitrogen fertilization
V. Nedvěd, J. Balík, J. Černý, M. Kulhánek, M. Balíkováhttps://doi.org/10.17221/435-PSECitation:Nedvěd V., Balík J., Černý J., Kulhánek M., Balíková M. (2008): The changes of soil nitrogen and carbon contents in a long-term field experiment under different systems of nitrogen fertilization. Plant Soil Environ., 54: 463-470.
Content of N and C in soil were investigated in a long-term field experiment under different systems of N fertilization. Chernozem and Cambisol were extracted using hot water (Nhws, Chws) and 0.01M CaCl2 (NCaCl2, CDOC). The Ct/Nt ratio in Chernozem was 9.6:1 and in Cambisol 6.1:1. The lowest Ct/Nt ratio in both experiments was found in the control treatment. Results showed that C and N compounds are less stable in Cambisol, which leads to a higher rate of mineralization. In the Chernozem, Nhws formed 3.66% from the total N content in the soil whereas NCaCl2 formed only 0.82%. Chws formed 2.98% and CDOC 0.34% from total C content. Cambisol contains 4.81% of Nhws and 0.84% of NCaCl2 from the total N amount and 5.76% of Chws and 0.70% of CDOC from the total C content, respectively. Nitrogen extracted by 0.01M CaCl2 formed only 22.4% of N extractable by hot water in Chernozem and 17.5% in Cambisol. The lowest C/N ratios were obtained after the CaCl2 extraction (3.0–6.2:1). The application of manure increased the content of soil organic N and C compared to the sewage sludge treatments.Keywords:long-term field experiment; nitrogen; carbon; sewage sludge; farmyard manure; soil organic matter