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Nitrogen immobilization in decomposing litter contributes to productivity decline in ageing pastures of green panic (Panicum maximum var. trichoglume)

Published online by Cambridge University Press:  27 March 2009

G. B. Robbins
Affiliation:
Queensland Department of Primary Industries, ‘Brian Pastures’ Research Station, Gayndah, Queensland 4625, Australia
J. J. Bushell
Affiliation:
Queensland Department of Primary Industries, ‘Brian Pastures’ Research Station, Gayndah, Queensland 4625, Australia
G. M. McKeon
Affiliation:
Queensland Department of Primary Industries, ‘Brian Pastures’ Research Station, Gayndah, Queensland 4625, Australia

Summary

The extent and rate of N release from nylon bags containing green panic (Panicum maximumvar.trichoglume)litter was measured for up to 319 days (long-term studies) in 1978/79 and 1979/80 in Gayndah, Australia. Dry matter (DM) decomposition rates were measured in 41 periods of 39 days and related to environmental variables and initial litter N concentrations (short-term study).

About half of litter DM decomposed during the long-term studies, while N concentration in the remaining litter increased from an initial average of 0–57 % N, to 0–95 % N. Net release of N from bags began when its concentration in the residue increased to c.0–65% N (or when the C:N ratio decreased to 75:1). Only a net 20–30 % of the initial N was released for potential plant uptake by the end of the study. The short-term study showed that DM decomposition was rapid and independent of pasture age. Decomposition rate increased with soil moisture and average daily temperature but was unaffected by initial litter N concentration. Release of N from decomposing litter was slow, despite rapid DM decomposition. It was concluded that a major cause of declining productivity in sown grass pastures is the immobilization of N in decomposing grass litter.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1989

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References

REFERENCES

Britton, C. M., Dodd, J. D. & Wiechert, A. T. (1978). Net aerial primary production of an Andropogon-Paspalum grassland ecosystem. Journal of Range Management 31, 381386.CrossRefGoogle Scholar
Bruce, R. C. & Ebersohn, J. P. (1982). Litter measurements in two grazed pastures in south-east Queensland. Tropical Grasslands 16, 180185.Google Scholar
Graham, T. W. G., Webb, A. A. & Waring, S. A. (1981). Soil nitrogen status and pasture productivity after clearing of brigalow (Acacia harpophylla). Australian Journal of Experimental Agriculture and Animal Husbandry 21, 109118.Google Scholar
Hunt, H. W. (1977). A simulation model for decomposition in grasslands. Ecology, USA 58, 469484.CrossRefGoogle Scholar
Jensen, J. L. (1929). On the influence of the carbon: nitrogen ratios of organic matter on the mineralization of nitrogen. Journal of Agricultural Science, Cambridge 19, 7182.CrossRefGoogle Scholar
Knapp, E. B., Elliott, L. F. & Campbell, G. S. (1983a). Microbial respiration and growth during the decomposition of wheat straw. Soil Biology and Biochemistry 15, 319323.CrossRefGoogle Scholar
Knapp, E. B., Elliott, L. F. & Campbell, G. S. (1983b). Carbon, nitrogen and microbial biomass interrelationships during the decomposition of wheat straw: a mechanism simulation model. Soil Biology and Biochemistry 15, 455461.CrossRefGoogle Scholar
Lutz, H. J. & Chandler, R. F. (1947). Forest Soils. New York: John Wiley and Sons.Google Scholar
McCown, R. L. (1973). An evaluation of the influence of available soil water storage capacity on growing season length and yield of tropical pastures using simple water balance models. Agricultural Meteorology 11, 5360.CrossRefGoogle Scholar
Meentemeyer, V. (1978). Macroclimate and lignin control of litter decomposition rates. Ecology, USA 59, 465472.CrossRefGoogle Scholar
Mott, J. J., McKeon, G. M., Gardener, C. J. & Mannetje, L. T (1981). Geographic variation in the reduction of hardseed content of Stylosanthesseeds in the tropics and subtropics of northern Australia. Australian Journal of Agricultural Research 32, 861869.CrossRefGoogle Scholar
Mulder, E. G., Lie, T. A. & Woldendorp, J. W. (1969). Biology and soil fertility. In Soil Biology, reviews of research, pp. 163208. Paris: UNESCO.Google Scholar
Rickert, K. G. & McKeon, G. M. (1982). Soil water balance model: WATSUP. Proceedings of the Australian Society of Animal Production 14, 198200.Google Scholar
Robbins, G. B. (1984). Relationships between productivity and age since establishment of pastures of Panicum maximum var.trichoglume. PhD thesis, University of Queensland.Google Scholar
Robbins, G. B., Bushell, J. J. & Butler, K. L. (1987). Decline in plant and animal production from ageing pastures of green panic (Panicum maximumvar. trichoglume). Journal of Agricultural Science, Cambridge 108, 407417.CrossRefGoogle Scholar
Rudder, T. H., Burrow, H., Seifert, G. W. & Maynard, P. J. (1982). The effects of year of birth, dam age, breeding and dam reproductive efficiency on live weights and age at sale of commercially managed steers in central Queensland. Proceedings of the Australian Society of Animal Production 14, 281284.Google Scholar
Seligman, N. G., Feigenhaum, S., Feinerman, D. & Benjamin, R. W. (1986). Uptake of nitrogen from high Cto-N ratio, 15N labelled organic residues by spring wheat grown under semi-arid conditions. Soil Biology and Biochemistry 18, 303307.CrossRefGoogle Scholar
Stace, H. C. T., Hubble, G. D., Brewer, R., Northcote, K. H., Sleeman, J. R., Mulcahy, M. J. & Hallsworth, E.G. (1968). A Handbook of Australian Soils. Glenside, South Australia: Rellim Technical Publications.Google Scholar
Swift, M. J., Heal, O. W. & Anderson, J. M. (1979). Studies in Ecology.Vol. 5. Decomposition in Terrestrial Ecosystems. Oxford: Blackwell Scientific Publications.Google Scholar
Wieder, R. K. & Lang, G. E. (1982). A critique of the analytical methods used in examining decomposition data from litter bags. Ecology, USA 63, 16361642.CrossRefGoogle Scholar
Williams, S. T. & Gray, T. R. G. (1974). Litter on the soil surface. In Biology of Plant Litter Decomposition, vol. 2 (Eds Dickinson, C. H. & Pugh, G. J. F.), pp. 611632. London: Academic Press.CrossRefGoogle Scholar