Fertilizer research

, Volume 34, Issue 1, pp 67–77 | Cite as

Acidulated pegmatitic mica: A promising new multi-nutrient mineral fertilizer

  • T. J. Weerasuriya
  • S. Pushpakumara
  • P. I. Cooray


Scrap grade pegmatitic phlogopite mica contains 5–7% K (∼8% K2O), 10–14% Mg (∼23% MgO), 1–2% Ca (∼2.9% CaO), 0.03% Mn and 109 ppm Zn. On acidulation upto 65% of K and Mg and 15–100% Mn and Zn were recovered. Less than 13% of Ca was recovered in solution. Water soluble and Nh4OAc extractable K and Mg of acidulated mica of pegmatitic origin increased a 102 to 103 times compared to untreated mica. Acidulated mica remained non-hygroscopic even when mixed with acids at a 2:1 mica to acid ratio. X-ray diffraction analyses demonstrated that interlayer cations were easily leached from the mica structure leaving behind a kaolinitic residue, compared to the more stable tetrasilicate feldspars.

The most significant achievement through these experiments was the yield increase obtained in the greenhouse experiment with rice by using the lowest application rate (200 kg ha−1) so far reported for mica, - an exponential decrease from tonnes/ha previously reported. Acidulated phlogopite mica chips (200 kg ha−1- 4 kg K, 8 kg Mg, trace elements Mn, Zn etc.) gave a yield increase of over 41% compared to a control with recommended muriate of potash and dolomite (17 kg K, 6 kg Mg). The response to acidulated feldspar (500 kg ha−1- 1.5 kg K) and an acidulated feldspar-dolomite combined fertilizer (250 kg ha−1- 0.6 kg K and 6 kg Mg) was not significant.

The response to mica clearly shows a multinutrient deficiency in highly weathered tropical soils. The relatively high solubility of the acidulated mica, its range of nutrient element supply, its nonhygroscopic nature and its extremely simple manufacturing process makes mica, a cheap but effective fertilizer for the tropical regions where these nutrients are deficient, especially in highly metamorphosed crystalline terrains.

Key words

Acidulated fertilizer mica mineral multi-nutrient pegmatitic rock powder feldspar 


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  1. Aitta Em, Leskela M, Moilan J and Jyrkas K (1987) The reaction between phlogopite and calcium chloride at elevated temperatures. J Chemical Technology and Biotechnology 3: 73–80Google Scholar
  2. Arkhipov NP, Pryanichnikov EV, Martyushov VV, Bazylev VV, Abramov VV, Rerikh VI and Laskovenkov AF (1988) The effect of phlogopite on the fertility of dernopodzolic soils and crop yield quality. Agrokhimiya 12: 78–81Google Scholar
  3. Berthelin J and Leyval C (1982) Ability of symbiotic and nonsymbiotic rhizospheric microflora of maize (Zea mays) to weather micas and to promote plant growth and plant nutrition. Plant Soil 68: 369–377Google Scholar
  4. Blum WEH, Herbinger B, Mentler F, Ottner M, Pollak E, Unger E and Wenzel WW (1989) Zur verwendung von gesteinsmelen in der landwirtschaft. II. Wirkung von gesteinsmehlen als bodenverbesserungsmittel. Z Pflanzenernahr Bodenk 152: 427–430Google Scholar
  5. Borsch L (1990) Potential of potash-rich rocks and minerals in agriculture: some preliminary tests. Agid Newsletter No. 61/62Google Scholar
  6. Chesworth W, Van Straaten P and Semoka JMR (1989) Agrogeology in east Africa: The Tanzania-Canada project. J Afr Earth Sci 9: 357–362Google Scholar
  7. Chesworth W, Macias-Vazquez F, Acquaye D and Thompson E (1983) Agriculture alchemy: stones int bread. Episodes 1: 3–7Google Scholar
  8. Fragstein P von and Vogtmann H (1983) Organic extracts for the treatment of rock powder fertilizers in biological agriculture. Biological Agriculture and Horticulture 1: 169–180Google Scholar
  9. Fyfe WS, Leonardos OH, Olorunfemi N (1983) Global tectonics and agriculture: A geochemical perspective. Agriculture, Ecosystems and Environment 9: 383–399.Google Scholar
  10. Gillman GP (1980) The effect of crushed basalt scoria on the cation exchange properties of a highly weathered soil. Soil Sci Soc Am J 44: 465–468Google Scholar
  11. Godefroy J, Muller M and Roose RC (1970) Estimation des partes par linivation des element fertilisants dans un sol de bananeraie de basse. Côte d'Ivoire. Fruits (Paris) 25(6): 403–420Google Scholar
  12. Jayakody AN and Kendaragama KMA (1989) Potassium leaching in a noncalcic brown soil under irrigated rice in Mahaweli system. B J Soil Sci Soc Sri Lanka 6: 30–45Google Scholar
  13. Kahnt G, Pfleiderer H, Hijazi LA (1986) Effect of ameliorative doses of rock powder and rock sand on growth of various agricultural crop plants and on physical properties of a sandy soil and clay soil. J Agronomy and Crop Sci 157: 169–180Google Scholar
  14. Keller WD (1948) Native rocks and minerals as fertilizers. Sci Month 66: 122–130Google Scholar
  15. Kithsiri KHSK (1992) A study of the potential use of acidulated and heat treated mica and acidulated feldspar as multinutritional fertilizer. BSc Thesis. University of Peradeniya, Peradeniya, Sri Lanka. 64 pGoogle Scholar
  16. Kronberg B I (1977) The geochemistry of some Brazilian soils and geochemical consideration for agriculture on highly leached soils. PhD Thesis. The University of Western Ontarion, London, Canada. 137 pGoogle Scholar
  17. Leonardos OH, Fyfe WS and Kronberg BI (1987) The use of ground rocks in laterite systems: An improvement to the use of conventional soluble fertilizers? In: Ogura Y (ed) Proceedings of an International Seminar on Laterite, October 14–17, 1985, Tokyo, Japan Chem Geol 60: 361–370Google Scholar
  18. Lundstrom U and Ohman LO (1990) Dissolution of feldspars in the presence of natural, organic solutes. J Soil Sci 41: 359–369Google Scholar
  19. Niwas JM, Dissanayake CB and Keerthisinghe G (1987) Rocks as fertilizers: Preliminary studies on potassium availability of some common rocks in Sri Lanka. Applied Geochemistry 2(2): 243–246Google Scholar
  20. Pushpakumara S, Weerasuriya TJ and Deturck P (1991) A new multi-element mica fertilizer for rice farming? I. Pot Experiments In: Fernando C (ed) Annual Review 1990, I F S Kandy, Sri Lanka. pp 62–64Google Scholar
  21. Robertson IDM and Eggleton RA Weathering of granitic muscovite to kaolinite and halloysite and of plagioclase-derived kaolinite to halloysite. Clays and Clay Minerals 39: 113-126Google Scholar
  22. Salcedo IH, Samaio EVSB and Andrade A (1982) Sources of phosphorus and potassium for pearl millet grown in a red yellow podzolic soil. Revista Brasileira de Ciencia+do Solo 6: 215–219Google Scholar
  23. Salinas JG, Saif SR, Kronberg BI, Fyfe WS and Walden DB (1986) Rock and glassy materials as nutrient conservative additives. In: Memorias de IX Congress Latin Americana de la Ciencia del SueloGoogle Scholar
  24. Sanz-Scovino JI and Rowell DL (1988) The use of feldspars as potassium fertilizers in the savannah of Colombia. Fertilizer Research 17: 71–83Google Scholar
  25. Song SK and Huang PM (1988) Dynamics of potassium release from potassium-bearing minerals as influenced by oxalic and citric acids. Soil Sci Soc Am J 52: 383–390Google Scholar
  26. Weerasuriya TJ, Pushpakumara S and Deturck P (1991) Acidulated pegmatitic mica: A promising new multi-element mineral fertilizer. In: Fernando C (ed) Annual Review 1990, I F S Kandy, Sri Lanka pp 60–62Google Scholar

Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • T. J. Weerasuriya
    • 1
    • 2
  • S. Pushpakumara
    • 1
  • P. I. Cooray
    • 1
  1. 1.Institute of Fundamental StudiesKandySri Lanka
  2. 2.Department of GeologyUniversity of PeradeniyaPeradeniyaSri Lanka

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