Journal of Soils and Sediments

, Volume 18, Issue 8, pp 2863–2867 | Cite as

Quantitative and qualitative characterisation of humic products with spectral parameters

  • Ekaterina Filcheva
  • Mariana HristovaEmail author
  • Pavlina Nikolova
  • Todorka Popova
  • Konstantin Chakalov
  • Valentin Savov
Humic Substances in the Environment



The application of different humic products for the treatment of soils and plants has increased in recent years. The characteristics of humic products, such as the content and composition of organic carbon and the maturity, provide valuable information which is essential for an adequate application. Such information is crucial for manufacturers, business consultants and users involved in the production, distribution and implementation of humic products. This article presents the correlation between the quantitative indicators of commercial humic products and their spectral characteristics via measurements in the ultraviolet spectrum at 300 nm, in the visible area at 445 and 665 nm and in the near-infrared spectrum at 850 nm.

Materials and methods

We evaluated humic products (liquid and solid) of different origins. Via wet combustion, the content of total organic carbon in humic products can be determined. The precipitation of humic acids from the starting solution determines the composition of the humic products in terms of humic acids (HAs) and fulvic acids (FAs). The dissolution of HAs determines their concentration by titration, while the specific extinction can be assessed via spectrophotometry via measuring the absorption of HAs spectra at the following wavelengths: 300, 465, 665 and 850 nm. The degree of aromaticity and condensation of humic products determines the optical density of the HAs via the E4/E6 ratio.

Results and discussion

The content of total organic carbon varied widely from 0.55 to 37.5% across all groups. The content of carbon in HAs, as a percentage of the total carbon in fulvic-type humic products, ranged from 1.29 to 16.00%, while in humic-type products, it ranged from 51.43 to 91.92%. The minimum value of the E4/E6 ratio was 2.97, while the maximum value was 6.35. We observed a direct relationship between the dominant type of acids in humic products and the E4/E6 ratio.


The optical density of HAs indicates their quality characteristics. The presented optical characteristics for humic products show that there is a direct relationship, especially between HAs/FAs and E4/E6 ratios. Measurement at 300 nm (E300) in the near-ultraviolet area and at 850 nm (E850) in the near-infrared area can increase the range of the spectral study.


E300 E850 Fulvic acids Humic acids Humic products Optical characteristics Ratio  E465/E665 


  1. Albrecht R, Le Petit J, Terrom G, Périssol C (2011) Comparison between UV spectroscopy and NIRS to assess humification process during sewage sludge and green wastes co-composting. Bioresour Technol 102(6):4495–4500CrossRefGoogle Scholar
  2. Amran ES, Chang HY, Jusoh FB, Liew JY (2017) Minimal duration of humic acid isolation from secondary forest soil of Kelantan, Malaysia. IJAR 3(4):362–366Google Scholar
  3. Blondeau R (1986) Comparison of soil humic and FAs of similar molecular weight. Org Geochem 9(1):47–50CrossRefGoogle Scholar
  4. Canellas LP, Façanha AR (2004) Chemical nature of soil humified fractions and their bioactivity. Pesquisa Agropecuaria Brasileira 39(3):233–240CrossRefGoogle Scholar
  5. Chen Y, Senesi N, Schnitzer M (1977) Information provided on humic products by E465/E665 ratios. Soil Sci Soc Am J 41(2):352–358CrossRefGoogle Scholar
  6. Debaene G, Bartmiński P, Niedźwiecki J, Miturski T (2017) Visible and near-infrared spectroscopy as a tool for soil classification and soil profile description. Polish J Soil Sci 50(1):1–10CrossRefGoogle Scholar
  7. Del Vecchio R, Blough NV (2004) On the origin of the optical properties of humic substances. Environ Sci Technol 38(14):3885–3891CrossRefGoogle Scholar
  8. Domeizel M, Khalil A, Prudent P (2004) UV spectroscopy: a tool for monitoring humification and for proposing an index of the maturity of compost. Bioresour Technol 94(2):177–184CrossRefGoogle Scholar
  9. Enev V, Pospíšilová L, Klucakova M, Liptaj T, Doskocil L (2014) Spectral characterization of selected humic substances. Soil Water Res 9(1):9–17CrossRefGoogle Scholar
  10. Eshwar M, Srilatha M, Rekha KB, Sharma SHK (2017) Characterization of humic substances by functional groups and spectroscopic methods. Int J Curr Microbiol App Sci 6(10):1768–1774CrossRefGoogle Scholar
  11. Flicheva E (2015) Characteristics of soil organic matter of Bulgarian soils. LAP Lambert Academic Publishing, p 178Google Scholar
  12. Filcheva E, Tsadilas CD (2002) Influence of clinoptilolite and compost on soil properties. Commun Soil Sci Plant Anal 33(3–4):595–607CrossRefGoogle Scholar
  13. Filcheva E, Ilieva R, Chakalov K, Popova T, Savov V, Hristova M (2017) Characterization of humic system in fertilizer raw materials. J Agric Sci Technol A 7(1):11–17Google Scholar
  14. Gonet SS, Debska B (2006) Dissolved organic carbon and dissolved nitrogen in soil under different fertilisation treatments. Plant Soil Environ 52(2):55CrossRefGoogle Scholar
  15. Guggenberger G (2005) Humification and mineralisation in soils. Microorganisms in soils: roles in genesis and functions:85–106Google Scholar
  16. Haynes RJ (2005) Labile organic matter fractions as central components of the quality of agricultural soils: an overview. Adv Agron 85:221–268CrossRefGoogle Scholar
  17. Jing-an S, Xiaohong T, Chaofu W, Deti X (2007) Effects of conservation tillage on soil organic matter in paddy rice cultivation. Acta Ecol Sin 27(11):4434–4442CrossRefGoogle Scholar
  18. Kalembasa D, Becher M (2009) Properties of organic matter in chosen soils fertilised with sewage sludge. Environ Protect Eng 35(2):165–171Google Scholar
  19. Kondratowicz-Maciejewska K (2007) Effects of crop rotation and different fertilisation systems on the content of dissolved organic carbon in soil. Humic Subsets Ecosys 7:79–82Google Scholar
  20. Kondratowicz-Maciejewska K, Kobierski M, Zdrodowski T (2011) Effect of soil management practices in orchards and cultivated fields on selected properties of humic substances. Polish J Soil Sci 44(2):167–176Google Scholar
  21. Kononova MM (1966) Soil organic matter, its nature, origin and role in soil fertility. Pergamon Press, Oxford, pp 400–410Google Scholar
  22. Peacock M, Evans CD, Fenner N, Freeman C, Gough R, Jones TG, Lebron I (2014) UV-visible absorbance spectroscopy as a proxy for peatland dissolved organic carbon (DOC) quantity and quality: considerations on wavelength and absorbance degradation. Environ Sci Process Impacts 16(6):1445–1461CrossRefGoogle Scholar
  23. Polak J, Bartoszek M, Żądło M, Kos A, Sułkowski WW (2011) The spectroscopic studies of humic acid extracted from sediment collected at different seasons. Chemosphere 84(11):1548–1555CrossRefGoogle Scholar
  24. Pospišilova L, Fasurova N (2009) Spectroscopic characteristics HAs originated in soils and lignite. Soil Water Res 4(4):168–175CrossRefGoogle Scholar
  25. Schindler FV, Mercer EJ, Rice JA (2007) Chemical characteristics of glomalin-related soil protein (GRSP) extracted from soils of varying organic matter content. Soil Biol Biochem 39(1):320–329CrossRefGoogle Scholar
  26. Song XY, Liu ST, Liu QH, Zhang WJ, Hu CG (2014) Carbon sequestration in soil humic products under long-term fertilisation in a wheat-maize system from North China. J Integrative Agr 13(3):562–569CrossRefGoogle Scholar
  27. Sparks DL, Fendorf SE, Toner CV, Carski TH (1996) Kinetic methods and measurements. Soil Sci Soc Am, Am Soc Agron 1275–1307Google Scholar
  28. Tahiri A, Richel A, Destain J, Druart P, Thonart P, Ongena M (2016) Comprehensive comparison of the chemical and structural characterisation of landfill leachate and leonardite humic fractions. Anal Bioanal Chem 408(7):1917–1928CrossRefGoogle Scholar
  29. Traina SJ, Novak J, Smeck NE (1990) An ultraviolet absorbance method of estimating the percent aromatic carbon content of HAs. J Environ Qual 19(1):151–153CrossRefGoogle Scholar
  30. Voroney RP, Brookes PC, Beyaert RP (2008) Soil microbial biomass C, N, P, and S. Soil sampling and methods of analysis. 2nd ed. CRC Press, Boca Rato, pp 637–651Google Scholar
  31. Weishaar JL, Aiken GR, Bergamaschi BA, Fram MS, Fujii R, Mopper K (2003) Evaluation of specific ultraviolet absorbance as an indicator of the chemical composition and reactivity of dissolved organic carbon. Environ Sci Technol 7(20):4702–4708CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Ekaterina Filcheva
    • 1
  • Mariana Hristova
    • 1
    Email author
  • Pavlina Nikolova
    • 1
  • Todorka Popova
    • 2
  • Konstantin Chakalov
    • 2
  • Valentin Savov
    • 3
  1. 1.N. Poushkarov Institute of Soil ScienceAgrotechnology and Plant ProtectionSofiaBulgaria
  2. 2.Balkan Plant Science Ltd.SofiaBulgaria
  3. 3.Sofia UniversitySofiaBulgaria

Personalised recommendations