Plant Soil Environ., 2025, 71(10):695-707 | DOI: 10.17221/250/2025-PSE
Contribution to the turbidimetric method for sulphur determination in arable soilsOriginal Paper
- 1 Analytical Chemistry Department, Faculty of Chemical Technologies, University of Chemical Тechnology and Metallurgy, Sofia, Bulgaria
- 2 ''Sembodja'' LtD, Sofia, Bulgaria
Sulphur (S) plays an important role in agriculture, being the fourth major contributor to improved quality of crops and increased yields. The applied methods for the estimation of different forms of S in soil aimed at assessing the sulphur availability to plants in various conditions. Nowadays, the wider spreading of regions with sulphur deficiency imposes optimisation of the soil testing procedures in order to increase their availability for laboratories. This study contributes to improving the analytical performance of the turbidimetric method in determining water-soluble sulphate in soil after leaching with the CaCl2 reagent. The modified testing protocol showed: method limit of quantification of 5.0 mg/kg; precision as relative standard deviation less than 3%; recovery of fortified soil samples 103 ± 18%. The expanded uncertainty was 2.3 mg/kg SO42–-S (K = 2, norm.). The proposed testing protocol was inexpensive, fast, used simple equipment and procedures, easily adoptable in regular laboratories, and showed characteristics suitable for the estimation of water-soluble sulfate in arable soils. A set of 546 soil samples was tested, and 74% were found to be sulphur deficient with SO42–-S < 10 mg/kg and sulfur availability index < 6.0. Thus, the availability of laboratory analysis to a broader group of farmers could contribute to effective fertilisation programs, as the newly proposed fertiliser blending technologies are based on adequate estimation of sulfur availability in arable soils.
Keywords: available sulfur; turbidimetry; soil testing; sulphate determination; standard addition
Received: June 6, 2025; Revised: September 5, 2025; Accepted: September 9, 2025; Prepublished online: October 10, 2025; Published: October 21, 2025 Show citation
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References
- Anderson C.G., Peverill I.K., Brennan F.R. (2013): Soil sulfur - crop response calibration relationships and criteria for field crops grown in Australia. Crop and Pasture Science, 64: 523-530.
Go to original source...
- Angelova L., Genova N., Stoyanova S., Surleva O., Nekov I.H., Ilieva D., Surleva A. (2021): Comparative study of soil test methods for determination of plant available potassium in Bulgarian arable soils. Analytics and Control, 25: 182-192.
Go to original source...
- Angelova L., Genova N., Pencheva G., Statkova Y., Yotova V., Surleva A. (2022): Contribution to the molybdenum blue reaction and its application in soil analysis. Methods and Objects of Chemical Analysis, 17: 59-69.
Go to original source...
- Asmarlaili S., Rauf A., Hanafiah D.S., Sudarno Y., Abdi P. (2018): The soil sulphate effect and maize plant (Zea mays L.) growth of sulphate-reducing bacteria (SRB) inoculation in acid sulfate soils with different soil water conditions. IOP Conference Series: Earth and Environmental Science, 122: 012037.
Go to original source...
- Brajendra A.K.V., Sarma M. (2016): Forms and status of sulphur availability in soils of Mizoram. Asian Journal of Soil Science and Plant Nutrition, 11: 197-201.
Go to original source...
- Camberato J., Casteel S. (2017): Sulfur deficiency. Purdue University Department of Agronomy, Soil Fertility Update. Available at: https://www.agry.purdue.edu/
- Combs S., Denning J., Frank K.D. (2011): Sulfate Sulfur in Recommended Chemical Soil Test Procedures for the North Central Region. North Central Regional Research Publication No. 221, 35.
- Esmel C.E., Santos B.M., Rechcing J.E., Toor G., Simonne E.H., Noling J.W. (2010): Searching for an ideal soil extractant for determining sulfur in sandy soils. Proceedings of the Florida State Horticultural Society, 123: 169-174.
- Kruve A., Rebane R., Kipper K., Oldekop M.L., Evard H., Herodes K., Ravio P., Leito I. (2015): Tutorial review on validation of liquid chromatography-mass spectrometry methods: part I. Analytica Chimica Acta, 870: 29-44.
Go to original source...
Go to PubMed...
- Kulhánek M., Cerný J., Balík J., Sedlář O., Suran P. (2018): Potential of the Mehlich 3 method for extracting plant available sulfur in the Czech agricultural soils. Plant, Soil and Environment, 64: 455-462.
Go to original source...
- Lisowska A., Filipek-Mazur B., Kalisz A., Gorczyca O., Kowalczyk A. (2023): Changes in soil sulfate sulfur content as an effect of fertilizer granules containing elemental sulfur. Halloysite and Phosphate Rock. Agronomy, 13: 1410.
Go to original source...
- Magnucka E.G., Kulczycki G., Oksinska M.P., Kucinska J., Paweska K., Milo Ł., Pietr S.J. (2023): The effect of various forms of sulfur on soil organic matter fractions and microorganisms in a pot experiment with perennial ryegrass (Lolium perenne L.). Plants, 12: 2649.
Go to original source...
Go to PubMed...
- Magnusson B., Örnemark U. (eds.) (2014) Eurachem Guide: The Fitness for Purpose of Analytical Methods - A Laboratory Guide to Method Validation and Related Topics. 2nd Edition. Available at: http://www.eurachem.org
- Narayan O.P., Kumar P., Yadav B., Dua M., Johri A.K. (2023): Sulfur nutrition and its role in plant growth and development. Plant Signaling and Behavior, 18: 2030082.
Go to original source...
Go to PubMed...
- Padhan D., Sen A., Rout P.P. (2016): Extractability and availability index of sulphur in selected soils of Odisha. Journal of Applied and Natural Science, 8: 1981-1986.
Go to original source...
- Sahrawat K.L., Murthy K.V.S., Wani S.P. (2009): Comparative evaluation of Ca chloride and Ca phosphate for extractable sulfur in soils with a wide range in pH. Journal of Plant Nutrition and Soil Science, 172: 404-407.
Go to original source...
- Scherer W.H., Welp G., Förster S. (2012): Sulfur fractions in particle-size separates as influenced by long-term application of mineral and organic fertilizers. Plant, Soil and Environment 58: 242-248.
Go to original source...
- Seaton F.M., Robinson D.A., Monteith D., Lebron I., Bürkner P., Tomlinson S., Emmett B.A., Smart S.M. (2023): Fifty years of reduction in sulphur deposition drives recovery in soil pH and plant communities. Journal of Ecology, 111: 464-478.
Go to original source...
- Sharma R.K., Cox M.S., Oglesby C., Dhillon J.S. (2024): Revisiting the role of sulfur in crop production: a narrative review. Journal of Agriculture and Food Research, 15: 101013.
Go to original source...
- Shirisha K., Sahrawat K.L., Murthy K.V.S., Wani S.P., Gajbhiye P.N., Kundu S. (2010): Comparative evaluation of ICP-AES and turbidimetric methods for determining extractable sulfur in soils. Journal of the Indian Society of Soil Science, 58: 323-326.
- Shukla K.A., Behera K.S. (2019): All India coordinated research project on micro- and secondary nutrients and pollutant elements in soils and plants: research achievements and future thrusts abstract. Indian Journal of Fertilisers, 15: 522-543.
- Singh R., Bhumbla D.K., Keefer R.F. (2011): Recommended soil sulfate-S tests. In: Recommended Soil Testing Procedures for the Northeastern United States, Rev. 5.
- Sverchkov I., Gvozdetskaya M. (2024): Quantitative determination of sulfate sulfur in soils and sediments using the S-Kα and S-Kβ X-ray spectra and PLS regression. Spectrochimica Acta Part B: Atomic Spectroscopy, 218: 106992.
Go to original source...
- Tabak M., Lepiarczyk A., Filipek-Mazur B., Bachara P. (2019): The effect of fertilization with ammonium nitrate enriched with ammonium sulfate on the quantity and quality of winter wheat grain yield as well as on soil properties. Plant, Soil and Environment, 65: 211-217.
Go to original source...
- Tabatabai M.A. (1987): Physicochemical Fate of Sulfate in Soils. Journal of the Air and Waste Management Association, 37: 34-38.
Go to original source...
- TSI (The Sulfur Institute) (2024): Sulfur in Agriculture. Washington, D.C., The Sulphur Institute. Available at: https://www.sulphurinstitute.org
- Van Biljon J.J., Fouche D., Botha A.D.P. (2004): Threshold values for sulphur in soils of the main maize-producing areas of South Africa. South African Journal of Plant and Soil, 21: 152-156.
Go to original source...
- Zbíral J., Smatanová M., Němec P. (2018): Sulphur status in agricultural soils determined using the Mehlich 3 method. Plant, Soil and Environment, 64: 255-259.
Go to original source...
- Zhao W.Z., Lu B., Yu J.B., Zhang B.B., Zhang Y. (2020): Determination of sulfur in soils and stream sediments by wavelength dispersive X-ray fluorescence spectrometry. Microchemical Journal, 156: 104840.
Go to original source...
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