Summary
Lettuce and tomato seeds were treated in Petri dishes with a humic acid derived from an oxidized coal and with fractions of the same humic acid obtained by ultrafiltration through membranes of known molecular cutoff and by extracting with buffers set at pH 4 and pH 5. The unfractionated humic acid was applied at 40, 100, 1000, and 5000 mg l-1 whereas the humic fractions were applied at 40, 100, and 200 mg l-1. Germination parameters such as the number of total germinated seeds, the velocity of seed germination, the fresh weight and dry weight of total seedlings were measured and related to the chemical and physicochemical properties of the humic material. No increase in the germination percentage or the germination rate was observed for either lettuce or tomato seeds. The fresh weight of total seedlings and per seedling increased in treatments with unfractionated humic acid with increasing concentrations for both lettuce and tomato plants without showing signs of growth inhibition up to 5000 mg l-1. This was attributed to cell elongation and more efficient water uptake. For the lettuce, the fresh weight both of total seedlings and per seedling was enhanced by treating the seeds with fractions of low molecular weight and high content of acidic functions, whereas the dry weight both of total seedlings and per seedling did not change with the humic fraction used. For the tomato seeds in contrast, the dry weight both of total seedlings and per seedling was increased by the use of unfractionated humic acid and by some of the humic fractions. An uptake of humic material by growing tomato seedlings was inferred.
Similar content being viewed by others
References
Azam F, Malik KA (1982) Effect of humic acid on seedling growth of wheat (Triticum aestivum L.) under different conditions. Pak J Bot 14:47–48
Calemma V, Rausa R (1987) EP Patent no. 0272727 A2
Dixit VK, Kishore N (1987) Effect of humic acid and fulvic acid fraction of soil organic matter on seed germination. Indian J Sci 1:202–206
Krogmeier MJ, Bremner JM (1989) Effects of phenolic acids on seed germination and seedling growth in soil. Biol Fertil Soils 8:116–122
Malik KA, Azam F (1985) Effect of humic acid on wheat (Triticum aestivum L.) seedling growth. Environ Exp Bot 25:245–252
Pagel M (1960) Über den Einfluss von Humusstoffen auf das Pflanzenwachsen. I. Einfluss von Humusstoffen auf Keimung und Wurzelwachstum. Albrecht Thaer Arch 4:450–468
Piccolo A (1984) Caratterizzazione chimica e chimico-fisica di un acido umico da torba. Uno studio di purificazione. Ann Ist Stud Dif Suolo 25:121–131
Piccolo A, Nardi S, Concheri G (1992a) Structural characteristics of humic substances as related to nitrate uptake and growth regulation in plant systems. Soil Biol Biochem 24:373–380
Piccolo A, Rausa R, Celano G (1992b) Characteristics of molecular size fractions of humic substances derived from oxidized coal. Chemosphere 24:1381–1387
Rausa R, Calemma V, Girardi E (1989) Humic acids by dry oxidation of coal with air under pressure. Analytical and spectroscopical characteristics. In: Proc Int Conf on coal science, vol 1 Tokyo, pp 237–240
Rauthan BS, Schnitzer M (1981) Effects of a soil fulvic acid on the growth and nutrient content of cucumber (Cucumis sativus) plants. Plant and Soil 63:491–495
Schnitzer M (1978) Humic substances: Chemistry and reactions. In: Khan SU, Schnitzer M (eds) Soil organic matter. Elsevier, Amsterdam, pp 1–57
Sneath PHA (1957) The application of computers to taxonomy. J Gen Microbiol 17:201–226
Smidova M (1962) Über den Einfluss von Na-Humat auf die Oxydations-Reduktionsprozesse in den Wurzeln von Winterweizenpflanzen. In: Studies about humus (Symp). Czechoslovak Akademy of Sciences, Prague, pp 291–304
Stevenson FJ, Ardakani MS (1972) Organic matter reactions involving micronutrients in soils. In: Mortvedt JJ, Giordano PM, Lindsay WL (eds) Micronutrients in agriculture. Am Soc Agron, Madison, Wisconsin, pp 79–114
van de Venter HA, Mari Furter, Dekker J, Cronje IJ (1991) Stimulation of seedling root growth by coal-derived sodium humate. Plant and Soil 138:17–21
Varshney TN, Gaur AC (1974) Effect of spraying sodium humate and hydroquinone on Glycine max L. var Bragg and Solanum Lycopersicum var Heiz 1370. Curr Sci 43:95–96
Vaughan D (1974) A possible mechanism for humic acid action on cell elongation in root segments of Pisum sativum under aseptic conditions. Soil Biol Biochem 6:241–247
Vaughan D, Linehan DJ (1976) The growth of wheat plants in humic acid solutions under axenic conditions. Plant and Soil 44:445–449
Vaughan D, Malcom RE (1985) Influence of humic substances on growth and physiological processes. In: Vaughan D, Malcom RE (eds) Soil organic matter and biological activity. Kluwer Academic Publisher, Amsterdam, The Netherlands, pp 37–46
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Piccolo, A., Celano, G. & Pietramellara, G. Effects of fractions of coal-derived humic substances on seed germination and growth of seedlings (Lactuga sativa and Lycopersicum esculentum). Biol Fertil Soils 16, 11–15 (1993). https://doi.org/10.1007/BF00336508
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00336508