Banger K., Kukal S. S., Toor G., Sudhir K., Hanumanthraju T. H. (2009): Impact of long-term additions of chemical fertilizers and farm yard manure on carbon and nitrogen sequestration under rice-cowpea cropping system in semi-arid tropics. Plant and Soil, 318, 27-35 https://doi.org/10.1007/s11104-008-9813-zČerný J., Balík J., Kulhánek M., Nedvěd V. (2008): The changes in microbial biomass C and N in long-term field experiments. Plant, Soil and Environment, 54, 212-218 https://doi.org/10.17221/393-PSEChen Y., Senesi N., Schnitzer M. (1977): Information Provided on Humic Substances by E4/E6 Ratios1. Soil Science Society of America Journal, 41, 352- https://doi.org/10.2136/sssaj1977.03615995004100020037x Dębska B. (2004): Properties of humic substances of soil fertilized with slurry. [PhD thesis] Bydgoszcz, Technical and Agricultural Academy. (In Polish)Diacono Mariangela, Montemurro Francesco (2010): Long-term effects of organic amendments on soil fertility. A review. Agronomy for Sustainable Development, 30, 401-422 https://doi.org/10.1051/agro/2009040Doni S., Macci C., Peruzzi E., Ceccanti B., Masciandaro G. (2014): Factors Controlling Carbon Metabolism and Humification in Different Soil Agroecosystems. The Scientific World Journal, 2014, 1-8 https://doi.org/10.1155/2014/416074Fließbach Andreas, Oberholzer Hans-Rudolf, Gunst Lucie, Mäder Paul (2007): Soil organic matter and biological soil quality indicators after 21 years of organic and conventional farming. Agriculture, Ecosystems & Environment, 118, 273-284 https://doi.org/10.1016/j.agee.2006.05.022 IUSS, Working Group WRB (2014): World Reference Base for Soil Resources. International Soil Classification System for Naming Soils and Creating Legends for Soil Maps. World Soil Resources Reports No. 106. Rome, FAO. Available at: www.fao.org/3/a-i3794e.pdfJäger Nadine, Stange Claus Florian, Ludwig Bernard, Flessa Heiner (2011): Emission rates of N2O and CO2 from soils with different organic matter content from three long-term fertilization experiments—a laboratory study. Biology and Fertility of Soils, 47, - https://doi.org/10.1007/s00374-011-0553-5Kawasaki Shigeki, Ikeya Kosuke, Sugiura Yuki, Watanabe Akira (2015): Changes in the composition of humic acids in various upland field soils with a continuous application of an organic amendment as revealed by fractional precipitation analysis. Soil Science and Plant Nutrition, 61, 450-460 https://doi.org/10.1080/00380768.2014.997649 Kononova M.M. (1966): Soil Organic Matter. Oxford, Pergamon Press.Lapa V. V., Seraya T. M., Bogatyreva E. N., Biryukova O. M. (2011): The effect of long-term fertilizer application on the group and fractional composition of humus in a soddy-podzolic light loamy soil. Eurasian Soil Science, 44, 100-104 https://doi.org/10.1134/S106422931101008XLithourgidis Anastasios S., Matsi Theodora, Barbayiannis Nikolaos, Dordas Christos A. (2007): Effect of Liquid Cattle Manure on Corn Yield, Composition, and Soil Properties. Agronomy Journal, 99, 1041- https://doi.org/10.2134/agronj2006.0332Moharana P.C., Sharma B.M., Biswas D.R., Dwivedi B.S., Singh R.V. (2012): Long-term effect of nutrient management on soil fertility and soil organic carbon pools under a 6-year-old pearl millet–wheat cropping system in an Inceptisol of subtropical India. Field Crops Research, 136, 32-41 https://doi.org/10.1016/j.fcr.2012.07.002 Sądej W., Namiotko A. (2011): Changes in the fractional composition of organic matter in soil caused by long-term organic, mineral and mixed organic and mineral fertilization. Polish Journal of Soil Science, 44: 105–116.Sądej W., Przekwas K. (2008): Fluctuations of nitrogen levels in soil profile under conditions of a long-term fertilization experiment. Plant, Soil and Environment, 54, 197-203 https://doi.org/10.17221/394-PSESądej Wiera, Żołnowski Andrzej Cezary, Marczuk Olga (2016): Content of phenolic compounds in soils originating from two long-term fertilization experiments. Archives of Environmental Protection, 42, 104-113 https://doi.org/10.1515/aep-2016-0047SCHNITZER M., SKINNER S. I. M. (1968): ALKALI VERSUS ACID EXTRACTION OF SOIL ORGANIC MATTER. Soil Science, 105, 392-396 https://doi.org/10.1097/00010694-196806000-00003 Schulz E., Travnikova L.S., Titova N.A., Kogut B.M., Körschens M. (2002): Influence of soil type and fertilization on accumulation and stabilization of organic carbon in different SOM fractions. In: Yuren J. (ed.): Proceedings of 12th ISCO Conference, 3. Technology and Method of Soil and Water Conservation: 304–308. Available at: http://tucson.ars.ag.gov/isco/isco12/VolumeIII/InfluenceofSoilType.pdfSeremesic Srdjan, Ćirić Vladimir, Milošev Dragiša, Vasin Jovica, Djalovic Ivica (2016): Changes in soil carbon stock under the wheat-based cropping systems at Vojvodina province of Serbia. Archives of Agronomy and Soil Science, 63, 388-402 https://doi.org/10.1080/03650340.2016.1218475 Šimková I., Kuklová M., Kukla J. (2014): Accumulation of Ct and Nt in humus and mineral soil layers: The effect of change of tree species composition in nudal beech forests. Folia Oecologica, 41: 82–91. Szymańska M., Korc M., Łabętowicz J. (2008): Effects of single liming of sandy soils not limed for more than 40 years in the light of results of long-term fertilizing experiment. Polish Journal of Soil Sciences, 41: 105–114.Watanabe Akira, Kawasaki Shigeki, Kitamura Shigeyuki, Yoshida Shigekata (2007): Temporal changes in humic acids in cultivated soils with continuous manure application. Soil Science and Plant Nutrition, 53, 535-544 https://doi.org/10.1111/j.1747-0765.2007.00170.xYan Dezhi, Wang Dejian, Yang Linzhang (2007): Long-term effect of chemical fertilizer, straw, and manure on labile organic matter fractions in a paddy soil. Biology and Fertility of Soils, 44, 93-101 https://doi.org/10.1007/s00374-007-0183-0Yanardağ İbrahim Halil, Zornoza R., Cano A. Faz, Yanardağ A. Büyükkılıç, Mermut A. R. (2015): Evaluation of carbon and nitrogen dynamics in different soil types amended with pig slurry, pig manure and its biochar by chemical and thermogravimetric analysis. Biology and Fertility of Soils, 51, 183-196 https://doi.org/10.1007/s00374-014-0962-3