Biology and Fertility of Soils

, Volume 3, Issue 4, pp 189–194 | Cite as

Evaluation of some phosphoroamides as soil urease inhibitors

  • H. S. Chai
  • J. M. Bremner


The effectiveness of six phosphoroamides for retardation of urea hydrolysis in soils was studied by determining the effects of 10 μg g−1 soil of each compound on the amounts of urea hydrolyzed when soils treated with urea were incubated at 10°, 20°, 30°, and 40°C for 3, 7, and 14 days. The phosphoroamides used wereN-(diaminophosphinyl)-cyclohexylamine,N-benzyl-N-methyl phosphoric triamide, diethyl phosphoric triamide, trichloroethyl phosphorodiamidate, dimethyl phosphoric triamide, andN-butyl phosphorothioic triamide [N-(n-butyl) thiophosphoric triamide]. The soils used were selected to obtain a range in properties, and the effects of the six phosphoroamides studied were compared with those of two compounds known to be among the most effective compounds thus far proposed for retardation of urea hydrolysis in soils (phenylphosphorodiamidate and hydroquinone). The data obtained showed that all six of the phosphoroamides evaluated compared favorably with hydroquinone as soil urease inhibitors and that two of them [N-butyl phosphorothioic triamide andN-(diaminophosphinyl)-cyclohexylamine] were superior to phenylphosphorodiamidate for retardation of urea hydrolysis in soils at 20°, 30°, or 40°C.

Key words

Phosphorodiamides Phosphorotriamides N-Butyl phosphorothioic triamide N-(Diaminophosphinyl)-cyclohexylamine Hydroquinone Phenylphosphorodiamidate Urea hydrolysis 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Beaton JD (1978) Urea: its popularity grows as a dry source of nitrogen. Crop Soils 30:11–14Google Scholar
  2. Cooke GW (1969) Fertilisers in 2000 A.D. In: Phosphorus in agriculture, Bulletin Doc No 53. Int Superphosphate and Compound Manufacturers' Assoc, Paris, pp 1–13Google Scholar
  3. Douglas LA, Bremner JM (1970) Extraction and colorimetric determination of urea in soils. Soil Sci Soc Am Proc 34:859–862Google Scholar
  4. Engelstad OP, Hauck RD (1974) Urea: will it become the most popular nitrogen carrier? Crop Soils 26:11–14Google Scholar
  5. Gasser JKR (1964) Urea as a fertilizer. Soils Fert 27:175–180Google Scholar
  6. Held P, Lang S, 'Itadler E, Klepel M, Drohne D, Hartbrich HJ, Rothe G, Scheler H, Grundmeier S, Trautmann A (1976) Agent for reducing the loss of plant-available nitrogen in cultivated soil. East German Patent No 122, 177 (Chem Abstr 87:67315w)Google Scholar
  7. Martens DA, Bremner JM (1984a) Effectiveness of phosphoroamides for retardation of urea hydrolysis in soils. Soil Sci Soc Am J 16:515–519Google Scholar
  8. Martens DA, Bremner JM (1984b) Urea hydrolysis in soils: factors influencing the effectiveness of phenylphosphorodiamidate as a retardant. Soil Biol Biochem 16:515–519Google Scholar
  9. Mulvaney RL, Bremner JM (1978) Evaluation of antimetabolites for retardation of urea hydrolysis in soils. Soil Sci Soc Am J 41:1024–1027Google Scholar
  10. Mulvaney RL, Bremner JM (1979) A modified diacetyl monoxime method for colorimetric determination of urea in soil extracts. Commun Soil Sci Plant Anal 10:1163–1170Google Scholar
  11. Mulvaney RL, Bremner JM (1981) Control of urea transformations in soils. In: Paul EA, Ladd JN (eds) Soil biochemistry, vol 5. Marcel Dekker, New York, pp 153–196Google Scholar
  12. Tomlinson TE (1970) Urea: agronomic applications. Proc Fert Soc 113:1–76Google Scholar
  13. Zantua MI, Bremner JM (1975) Comparison of methods of assaying urease activity in soils. Soil Biol Biochem 7:291–295Google Scholar

Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • H. S. Chai
    • 1
  • J. M. Bremner
    • 1
  1. 1.Department of AgronomyIowa State UniversityAmesUSA

Personalised recommendations