Nitrogen mineralisation in a sandy soil under native eucalypt forest and exotic pine plantations in relation to moisture content.  P. Hopmans, D. W. Flinn and P. W. Farrell.  July 1979.  7 pp. (unpubl.)

SUMMARY

Incubation tests were carried out to identify potential rates of ammonification and nitrification in the surface layer of a sandy soil collected from both a native eucalypt forest and an adjacent mature P. radiata plantation. Tests were conducted over a range of soil moisture contents and incubation periods covering 15 to 90 days. Ammonification rate was very high despite a C/N ratio in both soils of 31, but extractable nitrate plus nitrite was only detected for the longest incubation period. Ammonification was strongly dependent upon soil moisture content and was slightly higher in soils under eucalypt where up to 135 ppm ammonium was detected after 90 days.

These results suggest that on sandy soils similar to those studied here, loss of surface soil during practises such as windrowing should be minimised. They also suggest that in the re-establishment of pine on such sites, loss of N and organic matter by burning logging residue should be avoided and soil moisture should be conserved by controlling weed competition or by using logging residue as a surface mulch.

Also published:

Hopmans, P., Flinn, D.W. and Farrell, P.W. (1980)  Nitrogen mineralisation in a sandy soil under native eucalypt forest and exotic pine plantations in relation to moisture content.  Commun. In Soil Sci. and Plant Analysis. 11 (1): 71-9.