The effects of H2SO4 and (NH4)SO4 treatments on the chemistry of soil drainage water and pine seedlings in forest soil microcosms.

M. I. Stutter, M. S. Alam, S. J. Langan, Sarah Jane Woodin, R. P. Smart, M. S. Cresser

Research output: Contribution to journalArticle

Abstract

An experiment comparing effects of sulphuric acid and reduced N deposition on soil water quality and on chemical and physical growth indicators for forest ecosystems is described. Six H2SO4 and (NH4)(2)SO4 treatment loads, from 0 - 44 and 0 - 25 kmol(c) ha(-1) yr(-1), respectively were applied to outdoor microcosms of Pinus sylvestris seedlings in 3 acid to intermediate upland soils (calc-silicate, quartzite and granite) for 2 years. Different soil types responded similarly to H2SO4 loads, resulting in decreased leachate pH. but differently to reduced N inputs. In microcosms of calc-silicate soil, nitrification of NH4 resulted in lower pH and higher cation leaching than in acid treatments. By contrast, in quartzite and granite soils, (NH4)(2)SO4 promoted direct cation leaching, although leachate pH increased. The results highlighted the importance of soil composition on the nature of the cations leached, the SO, adsorption capacities and microbial N transformations. Greater seedling growth on calc-silicate soils under both treatment types was related to sustained nutrient availability. Reductions in foliar P and Mg with higher N treatments were observed for seedlings in the calc-silicate soil. There were few treatment effects on quartzite and granite microcosm tree seedlings since P limitation precluded seedling growth responses to treatments. Hence, any benefits of N deposition to seedlings on quartzite and granite soils appeared limited by availability of co-nutrients, exacerbated by rapid depletion of soil exchangeable base cations.

Original languageEnglish
Pages (from-to)392-408
Number of pages16
JournalHydrology and Earth System Sciences
Volume8
Issue number3
DOIs
Publication statusPublished - 2004

Keywords

  • acidification
  • manipulation
  • nitrogen
  • ammonium. deposition
  • soil
  • drainage
  • pine
  • microcosms
  • forest
  • excess nitrogen deposition
  • organic carbon
  • nitrification
  • heathland
  • sulfate
  • ecosystems
  • adsorption
  • calcium
  • Podsols

Cite this