Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Dynamics of ammonia volatilization from simulated urine patches and aqueous urea applied to pasture. III. Field verification of a simplified model


Published field experimental data [11, 15, 19] were used to compare measured NH3(g) losses following applications of urine or aqueous urea to pasture soils with values predicted by a simplified ammonia volatilization model [16]. Total measured losses were generally in close agreement with predictions. For example, predicted losses following applications of urine to a ryegrass-white clover pasture in Canterbury, New Zealand were 20.7% in summer and 22.4% in autumn and were highly correlated with measured losses of 21.5% and 24.4% respectively (r = 0.998).

The model was also tested for instantaneous rate of ammonia gas loss at 33 discrete sampling times for the summer experiment. Correlations were again highly significant (r = 0.951 for urine and r = 0.885 for urea).

The interception of urine solution by herbage and litter on the pasture surface is discussed and was shown to account for some of the discrepancies between measurements and predictions. Soil surface pH was confirmed as an important factor in determining the extent of ammonia gas loss, and the practicalities of measuring this parameter under field conditions are presented. It was concluded that the model offers the potential for predicting ammonia volatilization losses following urine or aqueous urea applications to short pasture in non-leaching, non-nitrifying environments.

This is a preview of subscription content, log in to check access.


  1. 1.

    Beauchamp EG, Kidd GE and Thurtell G (1978) Ammonia volatilization from sewage sludge applied in the field. J Environ Qual 7, 141–146

  2. 2.

    Bouwmeester RJB and Vlek PLG (1981) Rate control of ammonia volatilization from rice paddies. Atmos Environ 15, 131–140

  3. 3.

    Carran RA, Ball PR, Theobald PW and Collins MEG (1982) Soil nitrogen balances in urine-affected areas under two moisture regimes in Southland. NZ J Exp Agric 10, 377–381

  4. 4.

    Cowling DW and Lockyer DR (1981) Increased growth of ryegrass exposed to ammonia. Nature 292, 337–338

  5. 5.

    Denmead OT, Freney JR and Simpson JR (1976) A closed ammonia cycle within a plant canopy. Soil Biol Biochem 8, 161–164

  6. 6.

    Denmead OT, Freney JR and Simpson JR (1982) Dynamics of ammonia volatilization during furrow irrigation of maize. Soil Sci Soc Am J 46, 149–155

  7. 7.

    Doak BW (1952) Some chemical changes in the nitrogenous constituents of urine when voided on pasture. J Agric Sci 42, 162–171

  8. 8.

    Ernst JW and Massey HF (1960) The effects of several factors on volatilization of ammonia from urea in the soil. Soil Sci Soc Am Proc 24, 87–90

  9. 9.

    Freney JR, Simpson JR and Denmead OT (1981) Ammonia volatilization. In Clark FE and Rosswall T, eds. Terrestrial nitrogen cycles. Ecology Bull Stockholm 33, 291–302

  10. 10.

    Hales JM and Drewes DR (1979) Solubility of ammonia at low concentrations. Atmos Environ 13, 1133–1147

  11. 11.

    Holland PT and During C (1977) Movement of nitrate-N and transformations of urea-N under field conditions. NZ J Agric Res 20, 479–488

  12. 12.

    Lyster S, Morgan MA and O'Toole P (1980) Ammonia volatilization from soils fertilized with urea and ammonium nitrate. J Life Sci R Dubl Soc 1, 167–175

  13. 13.

    McGarity JW and Hoult EH (1971) The plant component as a factor in ammonia volatilization from pasture swards. J Br Grasslands Soc 26, 31–34

  14. 14.

    Nelson DW (1982) Gaseous losses of nitrogen other than through denitrification. In Stevenson J, ed. Nitrogen in agricultural soils. Agron 22, 327–359

  15. 15.

    Sherlock RR and Goh KM (1984) Dynamics of ammonia volatilization from simulated urine patches and aqueous urea applied to pasture. I. Field experiments. Fert Res 5(2): 181–197

  16. 16.

    Sherlock RR and Goh KM (1984) Dynamics of ammonia volatilization from simulated urine patches and aqueous urea applied to pasture. II. Theoretical derivation of a simplified model. Fert Res ibid.

  17. 17.

    Simpson DMH and Melsted SW (1962) Gaseous ammonia losses from urea solutions applied as a foliar spray to various grass sods. Soil Sci Soc Am Proc 26, 186–189

  18. 18.

    Soils of New Zealand Part 3 (1968) Soil Bureau Bulletin 26 (3), 118–119. New Zealand Department of Scientific and Industrial Research Publication

  19. 19.

    Vallis I, Harper LA, Catchpoole VR and Weier KL (1982) Volatilization of ammonia from urine patches in a subtropical pasture. Aust J Agric Res 33, 97–107

  20. 20.

    Vlek PLG and Stumpe JM (1978) Effects of solution chemistry and environmental conditions on ammonia volatilization from aqueous systems. Soil Sci Soc Am J 42, 416–421

  21. 21.

    Vlek PLG and Craswell ET (1981) Ammonia volatilization from flooded soils. Fert Res 2, 227–245

  22. 22.

    Volk G (1959) Volatile loss of ammonia following surface application of urea to turf or bare soils. Agron J 51, 746–749

  23. 23.

    Wahhab A, Randhawa MS and Alam SQ (1956) Loss of ammonia from ammonium sulphate under different conditions when applied to soils. Soil Sci 84, 249–255

  24. 24.

    Yamada Y, Wittwer SH and Bukovac MJ (1965) Penetration of organic compounds through isolated cuticular membranes with special reference to14C urea. Plant Physiol 40, 170–175

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Sherlock, R., Goh, K. Dynamics of ammonia volatilization from simulated urine patches and aqueous urea applied to pasture. III. Field verification of a simplified model. Fertilizer Research 6, 23–36 (1985).

Download citation

Key words

  • Ammonia volatilization
  • urine
  • urea
  • model
  • soil-surface pH