Ref ID: 8721
Ref Type: Journal
Authors: Smethurst, P. J., Herbert, A. M., and Ballard, L. M.
Pub Date: 2001
Journal Name: Soil Science Society of America Journal
Volume: 65
Issue: 3
Start Page: 795
End Page: 804
ISBN/ISSN: 0361-5995
Keywords: effect/eucalypt/plantation/fertiliser/soil/solution
Abstract: Add Concentrations of nutrients in soil solution may by important indicators of nutrient availability for forest plantations, but we were unaware of the extent to which these concentrations varied temporally and were affected by fertilizer treatments at various sites, The effect of fertilizing eucalypt plantations on the concentrations of NH4, NO3, and inorganic phosphate (Pi), and on electrical conductivity (EC) and pH in paste extracts was assessed at three sites in Tasmania, Australia, Nitrogen and P fertilizers were broadcast at elemental rates in the range 0 to 600 kg ha(-1) as (NH4)(2)SO4 and triple super-phosphate within 2 mo of planting, and again at 26 mo at two of the sites. Nutrient concentrations in undiluted soil solution were inferred by adjusting for the effects of dilution and buffering. Both fertilization events decreased pH by up to one-half a unit, and increased conductivity and the concentrations of NF4 and P-i by up to 10-fold in the 0- to 60 cm depth at all sites. Even at the highest rate of application, values of all parameters generally returned to unfertilized values before the second application of fertilizer, Rates of decrease in concentrations of NH4 and P-i after fertilization were unaffected by the age of the crop. When broadcast, applications of fertilizers may be needed at 2- to 4-yr intervals to maintain high nutrient availability. A single application of (NH4)(2)SO4 to these soils at a typical rate of 200 kg N ha(-1) will have
minimal effect on pH, but multiple applications could decrease pH and adversely affect Ca, K, and Mg availability.
Notes: Entered by Maria (9/5/2001):
Reprint: Not in File
Program: SPF Sustainable Management
Project: B1
Deliverable:
Confidentiality: Public
Availability: Authors
Report: Annual Report 2000/1
Type: Article
Address: Philip.Smethurst@ffp.csiro.au