Journal of Soils and Sediments

, Volume 18, Issue 8, pp 2881–2891 | Cite as

Humic products in agriculture: potential benefits and research challenges—a review

  • Daniel C. OlkEmail author
  • Dana L. Dinnes
  • J. Rene Scoresby
  • Chad R. Callaway
  • Jerald W. Darlington
Humic Substances in the Environment


Humic products have been used in cropland agriculture for several decades, but lack of widespread credibility has restricted their use to small proportions of farmers. To improve the credibility of humic products, we identify four knowledge gaps and propose pathways of future action to close these gaps. First, while the capacity of humic products to improve plant growth has been proven in greenhouse and growth chambers, more such work is needed in field conditions, especially to determine the modifying effects on humic product efficacy of environmental and management factors, including crop type, annual weather patterns, soil type, and fertility management. Many of the published field studies fail to address any of these factors. Second, full acceptance of humic products by the research community may first require a mechanistic explanation for plant responses to humic products. Some research groups are exploring plant-based mechanisms, but almost entirely in controlled conditions, not in field conditions. Industry often attributes yield responses to enhancement of soil nutrient availability without citing adequate evidence. Microbial-based explanations are also possible. Third, consumer trust in available humic products would be strengthened through industry-wide measures for quality control of humic product production and sale, including standard procedures for measuring their humic and fulvic acid contents and rapid bio-assays for distinguishing effective products from inert frauds. Finally, humic products are widely presumed to promote root growth, which offers the potential to increase soil C inputs and thereby improve soil health. Yet virtually, no such evidence has been presented, in part due to the absence of long-term field trials. Humic product companies in North America have organized a trade association to promote a more knowledge-based industry. To acquire a database that will support these objectives, we propose establishment of a global network of field sites that would measure crop responses to humic products across ranges of humic products, crop types, soil types, and climates. Plant and soil samples would be analyzed by cooperating specialists in advanced laboratories to identify mechanistic processes and benefits to both plant production and soil health. We believe the industry will indeed become more knowledge-based and the credibility of humic products will improve as (i) we learn more about their field efficacy across ranges of field conditions for improving crop yield and soil health, (ii) we gain further insights into possible mechanistic explanations, and (iii) the consumer gains the ability to discern genuine products from fraudulent materials.


Crop yield Environmental stresses Humic products Standard methods 


Compliance with ethical standards

Conflict of interest

DC Olk and DL Dinnes received research grants from Minerals Technologies, Inc. (JR Scoresby and JW Darlington) and separately from Ag Logic Distributors (CR Callaway), but results from those projects are not presented here.


  1. Aguirre E, Leménager D, Bacaicoa E, Fuentes M, Baigorri R, Zamarreño AM, García-Mina JM (2009) The root application of a purified leonardite humic acid modifies the transcriptional regulation of the main physiological root responses to Fe deficiency in Fe-sufficient cucumber roots. Plant Physiol Biochem 47(3):215–223. CrossRefGoogle Scholar
  2. Ahmad W, Shah Z, Khan F, Ali S, Malik W (2014) Maize yield and soil properties as influenced by integrated use of organic, inorganic and bio-fertilizers in a low fertility soil. Soil Environ 32(2):121–129Google Scholar
  3. Albayrak S, Camas N (2005) Effects of different levels and application times of humic acid on root and leaf yield and yield components of forage turnip (Brassica rapa L.) J Agron 4(2):130–133CrossRefGoogle Scholar
  4. Almarshadi MHS, Ismail SM (2014) Barley growth and productivity as affected by soil amendments under fully ++and minimum irrigation conditions in Saudi Arabia. Life Sci J 11(4):223–230Google Scholar
  5. Aşik BB, Turan MA, Çelik H, Katkat AV (2009) Effects of humic substances on plant growth and mineral nutrients uptake of wheat (Triticum durum cv. Salihli) under conditions of salinity. Asian J Crop Sci 1:87–95CrossRefGoogle Scholar
  6. Aydin A, Kant C, Turan M (2012) Humic acid application alleviate salinity stress of bean (Phaseolus vulgaris L.) plants decreasing membrane leakage. Afr J Agric Res 7.
  7. Azarpour E, Motamed MK, Moraditochaee M, Bozorgi HR (2012) Effects of bio, mineral nitrogen fertilizer management, under humic acid foliar spraying on fruit yield and several traits of eggplant (Solanum melongena L.) Afr J Agric Res 7(7):1104–1109Google Scholar
  8. Balesdent J, Balabane M (1996) Major contribution of roots to soil carbon storage inferred from maize cultivated soils. Soil Biol Biochem 28(9):1261–1263. CrossRefGoogle Scholar
  9. Berbara RLL, Garcia AC (2014) Humic substances and plant defense metabolism. In: Ahmad P, Wani MR (eds) Physiological mechanisms and adaptation strategies in plants under changing environment, vol 1. Springer Science-Business Media, New York, pp 297–319CrossRefGoogle Scholar
  10. Bertrand I, Chabbert B, Kurek B, Recous S (2006) Can the biochemical features and histology of wheat residues explain their decomposition in soil? Plant Soil 281(1-2):291–307. CrossRefGoogle Scholar
  11. Billingham K (2012) Humic products:—potential or presumption for agriculture. NSW Dept Primary Industries, OrangeGoogle Scholar
  12. Brownell JR, Nordstrom G, Marihart J, Jorgensen G (1987) Crop responses from two new Leonardite extracts. Sci Total Environ 62:491–499. CrossRefGoogle Scholar
  13. California Department of Food and Agriculture (1996) Humic acid method. Method number HA4/JC, Agricultural Commodities & Regulatory Services Section, Center for Analytical Chemistry, September 30, 1996Google Scholar
  14. Calvo P, Nelson L, Kloepper JW (2014) Agricultural uses of plant biostimulants. Plant Soil 383(1-2):3–41. CrossRefGoogle Scholar
  15. Canellas LP, Olivares FL (2014) Physiological responses to humic substances as plant growth promoter. Chem Biol Tech Agric 1(1):3. CrossRefGoogle Scholar
  16. Canellas LP, Olivares FL, Okorokova-Façanha AL, Façanha AR (2002) Humic acids isolated from earthworm compost enhance root elongation, lateral root emergence, and plasma membrane H+-ATPase activity in maize roots. Plant Physiol 130(4):1951–1957. CrossRefGoogle Scholar
  17. Canellas LP, Olivares FL, Aguiar NO, Jones DL, Nebbioso A, Mazzei P, Piccolo A (2015) Humic and fulvic acids as biostimulants in horticulture. Sciencia Horticulturae 196:15–27. CrossRefGoogle Scholar
  18. Carletti P, Masi A, Spolaore B, Polverino De Laureto P, De Zorzi M, Turetta L, Ferretti M, Nardi S (2008) Protein expression changes in maize roots in response to humic substances. J Chem Ecol 34(6):804–818. CrossRefGoogle Scholar
  19. Cassman KG (1999) Ecological intensification of ceral production systems: yield potential, soil quality, and precision agriculture. PNAS 96(11):5952–5959. CrossRefGoogle Scholar
  20. Chen Y, Aviad T (1990) Effects of humic substances on plant growth. In: Humic substances in soil and crop sciences: selected readings. Am Soc Agron, Madison, pp 161–186Google Scholar
  21. Chen Y, Clapp CE, Magen H (2004) Mechanisms of plant growth stimulation by humic substances: the role of organo-iron complexes. Soil Sci Plant Nutr 50:1089–1095CrossRefGoogle Scholar
  22. Daur I, Bakhashwain AA (2013) Effect of humic acid on growth and quality of maize fodder production. Pak J Bot 45:21–25Google Scholar
  23. Dinnes DL, Karlen DL, Jaynes DB, Kaspar TC, Hatfield JL, Colvin TS, Cambardella CA (2002) Nitrogen management strategies to reduce nitrate leaching in tile-drained Midwestern soils. Agron J 94(1):153–171. CrossRefGoogle Scholar
  24. Ece A, Saltali K, Eryigit N, Uysal F (2007) The effects of Leonardite applications on climbing bean (Phaseolus vulgaris L.) yield and the some soil properties. J Agron 6(3):480–483CrossRefGoogle Scholar
  25. El-Mesker HKA, Mohamed ZEOM, Ali MAM (2014) Influence of humic acid and some micronutrients on yellow corn yield and quality. World Appl Sci J 32(1):1–11Google Scholar
  26. El-Shabrawy RA, Ramadan AY, El-Kady SM (2010) Use of humic acid and some biofertilizers to reduce nitrogen rates on cucumber (Cucumis sativus L.) in relation to vegetative growth, yield and chemical composition. J Plant Prod Mansoura Univ 1(8):1041–1051Google Scholar
  27. Farenhorst A (2006) Importance of soil organic matter fractions in soil─landscape and regional assessments of pesticide sorption and leaching in soil. Soil Sci Soc Am J 70(3):1005–1012. CrossRefGoogle Scholar
  28. Feibert EBG, Shock CC, Saunders LD (2003) Nonconventional additives leave onion yield and quality unchanged. HortSci 38:381–386Google Scholar
  29. Ferguson RB, Hergert GW, Schepers JS, Gotway CA, Cahoon JE, Peterson TA (2002) Site-specific nitrogen management of irrigated maize: yield and soil residual nitrogen effects. Soil Sci Soc Am J 66(2):544–553. CrossRefGoogle Scholar
  30. Fernandez-Escobar R, Benlloch M, Barranco D, Duenas A, Guterrez-Ganan JA (1996) Response of olive trees to foliar application of humic substances extracted from Leonardite. Sci Hort 66(3-4):191–200. CrossRefGoogle Scholar
  31. Gale WJ, Cambardella CA (2000) Carbon dynamics of surface residue- and root-derived organic matter under simulated no-till. Soil Sci Am J 64(1):190–195. CrossRefGoogle Scholar
  32. Gümüs İ, Şeker C (2015) Influence of humic acid applications on modulus of rupture, aggregate stability, electrical conductivity, carbon and nitrogen content of a crusting problem soil. Solid Earth 6(4):1231–1236. CrossRefGoogle Scholar
  33. Hartz TK, Bottoms TG (2010) Humic substances generally ineffective in improving vegetable crop nutrient uptake of productivity. HortSci 45:906–910Google Scholar
  34. Ismail AF, Hussien SM, El-Shall SA, Fathi MA (2007) Effect of irrigation rate and humic acid on “Le-Conte” pear. J Agric Sci Mansoura Univ 32(9):7589–7603Google Scholar
  35. Jaynes DB, Dinnes DL, Meek DW, Karlen DL, Cambardella CA, Colvin TS (2004) Using the late spring nitrate test to reduce nitrate loss within a watershed. J Environ Qual 33(2):669–677. CrossRefGoogle Scholar
  36. Jaynes DB, Kaspar TC, Colvin TS (2011) Economically optimal nitrogen rates of corn: management zones delineated from soil and terrain attributes. Agron J 103(4):1026–1035. CrossRefGoogle Scholar
  37. Khan RU, Rashid A, Khan MS, Ozturk E (2010) Impact of humic acid and chemical fertilizer application on growth and grain yield of rainfed wheat (Triticum aestivum L.) Pak J Agric Res 23(3–4):113–121Google Scholar
  38. Khristeva LA (1953) The participation of humic acids and other organic substances in the nutrition of higher plants. Pochvivedenie 10:46–59Google Scholar
  39. Khristeva LA (1968) About the nature of physiologically active substances of the soil humus and of organic fertilizers and their agricultural importance. In: Study week on organic matter and soil fertility, Pontifical Academy of Sciences, Vatican City. North-Holland Publishing Company and John Wiley, New York, pp 701–721Google Scholar
  40. Khristeva LA, Manoilova A (1950) The nature of the direct effect of humic acids on the growth and development of plants. Dokl vsesoyuz Akad s-kh Nauk Lenina 11:10–16Google Scholar
  41. Lamar RT, Talbot KH (2009) Critical comparison of humic acid test methods. Comm Soil Sci Plant Anal 40(15-16):2309–2322. CrossRefGoogle Scholar
  42. Lamar RT, Olk DC, Mayhew L, Bloom PR (2014) A new standardized method for quantification of humic and fulvic acids in humic ores and commercial products. J AOAC INTERNATIONAL 97(3):721–730. CrossRefGoogle Scholar
  43. Lee YS, Bartlett RJ (1976) Stimulation of plant growth by humic substances. Soil Sci Soc Am J 40(6):876–879. CrossRefGoogle Scholar
  44. Mahmoud AR, Hafez MM (2010) Increasing productivity of potato plants (Solanum tuberosum L.) by using potassium fertilizer and humic acid application. Int J Acad Res 2(2):83–88Google Scholar
  45. Mendez-Millan M, Dignac M-F, Rumpel C, Rasse DP, Derenne S (2010) Molecular dynamics of shoot vs. root biomarkers in an agricultural soil estimated by natural abundance 13C labelling. Soil Biol Biochem 42(2):169–177. CrossRefGoogle Scholar
  46. Mohammedpourkhaneghah A, Shahryari R, Alaei Y, Shahmoradmoghanlou B (2012) Comparison of the effect of liquid humic fertilizers on yield of maize genotypes in Ardabil region. Afr J Biotechnol 11:4810–4814Google Scholar
  47. Mora V, Bacaicoa E, Zamarreño A-M, Aguire E, Garnica M, Fuentes M, García-Mina J-M (2010) Action of humic acid on promotion of cucumber shoot growth involves nitrate-related changes associated with the root-to-shoot distribution of cytokinins, polyamines and mineral nutrients. J Plant Physiol 167(8):633–642. CrossRefGoogle Scholar
  48. Moraditochaee M (2012) Effects of humic acid foliar spraying and nitrogen fertilizer management on yield of peanut (Arachis hypogaea L.) in Iran. ARPN J Agric Biol Sci 7(4):289–293Google Scholar
  49. Murdock L (2017) Breakdown of subsoil fragipan by a humic product. Proceedings, 2017 Annual meeting of the ASA-CSSA-SSSA, Tampa, FL, Oct. 22-25Google Scholar
  50. Nardi S, Pizzeghello D, Muscolo A, Vianello A (2002) Physiological effects of humic substances on higher plants. Soil Biol Biochem 34(11):1527–1536. CrossRefGoogle Scholar
  51. Nazli RI, Kusvuran A, Inal I, Demirbas A, Tansi V (2014) Effects of different organic materials on forage yield and quality of silage maize (Zea mays L.) Turk J Agric For 38:23–31. CrossRefGoogle Scholar
  52. NCR-103 Committee (n.d.) Compendium of research reports on use of non-traditional materials for crop production.
  53. Official Gazette of the Italian Republic (2001). Extraction and fractionation of organic carbon from peat, leonardite, lignite humified and composted materials. January 26, 2001 N. 21, Ministerial Decree of December 21, 2000, Supplement N. 6Google Scholar
  54. Olk DC, Dinnes DL, Callaway C, Raske M (2013) On-farm evaluation of a humic product in Iowa (US) maize production. In: Xu J et al (eds) Functions of natural organic matter in changing environment. Zhejiang University Press and Springer Science+Business Media, Dordrecht, pp 1047–1050. CrossRefGoogle Scholar
  55. Olk DC, Dinnes DL, Scoresby R, Darlington J (2017) Improved soil physical properties with long-term application of humic product in corn-soybean rotations. Proceedings, 2017 Annual meeting of the ASA-CSSA-SSSA, Tampa, FL, Oct 22-25Google Scholar
  56. Parkin TB (1987) Soil microsites as a source of denitrification variability. Soil Sci Soc Am J 51(5):1194–1199. CrossRefGoogle Scholar
  57. Power JF, Wiese RA, Flowerday AD (2000) Managing nitrogen for water quality—lessons from the management systems evaluation area. J Environ Qual 29(2):355–366. CrossRefGoogle Scholar
  58. Randall GW, Huggins DR, Russelle MP, Fuchs DJ, Nelson WW, Anderson JL (1997) Nitrate losses through subsurface tile drainage in conservation reserve program, alfalfa, and row crop systems. J Environ Qual 26(5):1240–1247. CrossRefGoogle Scholar
  59. Rizk FA, Shaheen AM, Singer SM, Omminma AS (2013) The productivity of potato plants affected by urea fertilizer as foliar spraying and humic acid added with irrigation water. Mid East J Agric Res 2(2):76–83Google Scholar
  60. Robert PC (2002) Precision agriculture: a challenge for crop nutrition management. Plant Soil 247(1):143–149. CrossRefGoogle Scholar
  61. Rose MT, Patti AF, Little KR, Brown AL, Jackson WR, Cavagnaro TR (2014) A meta-analysis and review of plant-growth response to humic substances: practical implications for agriculture. Adv Agron 124:37–89. CrossRefGoogle Scholar
  62. Saha R, Saieed MAU, Chowdhury MAK (2013) Growth and yield of rice (Oryza sativa) as influenced by humic acid and poultry manure. Univ J Plant Sci 1(3):78–84Google Scholar
  63. Sajid M, Rab A, Shah ST, Jan I, Haq I, Haleema B, Zamin M, Alam R, Zada H (2012) Humic acids affect the bulb production of onion cultivars. Afr J Micro Res 6(28):5769–5776Google Scholar
  64. Sanli A, Karadogan T, Tonguc M (2013) Effects of Leonardite applications on yield and some quality parameters of potatoes (Solanum tuberosum L.) Turk J Field Crops 18(1):20–26Google Scholar
  65. Saruhan V, Kusuran A, Babat S (2011) The effect of different humic acid fertilization on yield and yield components performances of common millet (Panicum miliaceum L.) Sci Res Ess 6(3):663–669Google Scholar
  66. Savvides A, Ali S, Tester M, Fotopoulos V (2016) Chemical priming of plants against multiple abiotic stresses: mission possible? Trends Plant Sci 21(4):329–340. CrossRefGoogle Scholar
  67. Scharf PC, Kitchen NR, Sudduth KA, Davis JG, Hubbard VC, Lory JA (2005) Field-scale variability in optimal nitrogen fertilizer rate for corn. Agron J 97(2):452–461. CrossRefGoogle Scholar
  68. Schepers JS, Mosier AR (1991) Accounting for nitrogen in nonequilibrium soil-crop systems. In: Follett RF et al (eds) Managing nitrogen for groundwater quality and farm profitability. Soil Science Society of America, Madison, pp 125–138Google Scholar
  69. Selim EM, Mosa AA (2012) Fertigation of humic substances improves yield and quality of broccoli and nutrient retention in a sandy soil. J Plant Nutr Soil Sci 175(2):273–281. CrossRefGoogle Scholar
  70. Selim EM, El-Neklawy AS, El-Ashry SM (2009a) Beneficial effects of humic substances fertigation on soil fertility to potato grown on sandy soil. Aust J Basic Appl Sci 3:4351–4358Google Scholar
  71. Selim EM, Mosa AA, El-Ghamry AM (2009b) Evaluation of humic substances fertigation through surface and subsurface drip irrigation systems on potato grown under Egyptian sandy soil conditions. Agric Water Manag 96(8):1218–1222. CrossRefGoogle Scholar
  72. Selim EM, Shedeed SI, Asaad FF, El-Neklawy (2012) Interactive effects of humic acid and water stress on chlorophyll and mineral nutrient contents of potato plants. J Appl Sci Res 8(1):531–537Google Scholar
  73. Seyedbagheri M-M (2010) Influence of humic products on soil health and potato production. Potato Res 53(4):341–349. CrossRefGoogle Scholar
  74. Shahryari R, Valizadeh M, Mollasadeghi V (2012) Selection based on tolerance of wheat against terminal drought: focus on grain yield at the presence of liquid humic fertilizer. Afr J Agric Res 6(9):4494–4500Google Scholar
  75. Sleighter RL, Caricasole P, Richards KM, Hanson T, Hatcher PG (2015) Characterization of terrestrial dissolved organic matter fractionated by pH and polarity and their biological effects on plant growth. Chem Biol Tech Agric 2(1):9. CrossRefGoogle Scholar
  76. Spanish Official State Gazette (1991) Extraction of total humics and humic acids. Official methods for the analysis of organic fertilizer products. Method 18408, Royal Decree 1110/1991Google Scholar
  77. Swift R (1996) Organic matter characterization. In: Sparks DL et al (eds) Methods of soil analysis, part 3 chemical methods. Soil Science Society of America, Madison, pp 1011–1069Google Scholar
  78. Turgay OC, Karaca A, Unver S, Tamer N (2011) Effects of coal-derived humic substances on some soil properties and bread wheat yield. Commun Soil Sci Plant Anal 42(9):1050–1070. CrossRefGoogle Scholar
  79. Van Zomeren A, Comans RNJ (2007) Measurement of humic and fulvic acid concentrations and dissolution properties by a rapid batch procedure. Environ Sci Technol 41(19):6755–6761. CrossRefGoogle Scholar
  80. Vanitha K, Mohandass S (2014) Effect of humic acid on plant growth characters and grain yield of drip fertigated aerobic rice (Oryza sativa L.) Bioscan 9(1):45–50Google Scholar
  81. Vaughan D (1986) Effect of humic substances on metabolic processes. In: Burns RG et al (eds) Humic substances: effects on soil and plants. Ramo Editoriale degli Agricoltori, Rome, pp 54–77Google Scholar
  82. Vaughan D, Malcolm RE (1985) Influence of humic substances on growth and physiological processes. In: Vaughan D, Malcolm RE (eds) Soil organic matter and biological activity. Martinus Nijhoff, Dordrecht, pp 37–75. CrossRefGoogle Scholar
  83. Vaughan D, Malcolm RE, Ord BG (1985) Influence of humic substances on biochemical processes in plants. In: Vaughan D, Malcolm RE (eds) Soil organic matter and biological activity. Martinus Nijhoff, Dordrecht, pp 78–108CrossRefGoogle Scholar
  84. Verlinden G, Pycke B, Mertens J, Debersaques F, Verheyen K, Baert G, Bries J, Haesaert G (2009) Application of humic substances results in consistent increases in crop yield and nutrient uptake. J Plant Nutr 32(9):1407–1426. CrossRefGoogle Scholar
  85. Visser SA (1986) Effects of humic substances on plant growth. In: Burns RG et al (eds) Humic substances: effects on soil and plants. Ramo Editoriale degli Agricoltori, Rome, pp 89–135Google Scholar
  86. Wollenhaupt NC, Wolkowski RP, Clayton MK (1994) Mapping soil test phosphorus and potassium for variable-rate fertilizer application. J Prod Agric 7(4):441–448. CrossRefGoogle Scholar
  87. Xudan X (1986) Effect of foliar application of fulvic acid on water use, nutrient uptake and yield in wheat. Aust J Agric Res 37(4):343–350. CrossRefGoogle Scholar
  88. Zaki HEM, Toney HSH, Abd Elraouf RM (2014) Response of two garlic cultivars (Allium sativum L.) to inorganic and organic fertilization. Nat Sci 12(10):52–60Google Scholar
  89. Zandonadi DB, Santos MP, Busato JG, Peres LEP, Façanha AR (2013) Plant physiology as affected by humified organic matter. Theor Exp Plant Physiol 25:12–25CrossRefGoogle Scholar
  90. Zhang L, Zhou J, Zhao YG, Zhai Y, Wang K, Alva A, Paramasivam S (2013) Optimal combination of chemical compound fertilizer and humic acid to improve soil and leaf properties, yield and quality of apple (Malus Domestica) in the loess plateau of China. Pak J Bot 45(4):1315–1320Google Scholar

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© This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2018

Authors and Affiliations

  1. 1.National Laboratory for Agriculture and the EnvironmentUSDA-ARSAmesUSA
  2. 2.Minerals Technologies, Inc.New YorkUSA
  3. 3.Ag Logic DistributorsConradUSA

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