Land-use and fertilization effects on P forms in two European soils: Resin extraction and 31P-NMR analysis

authored by
G. Guggenberger, B. T. Christensen, G. Rubæk, W. Zech
Abstract

Macroporous anion-exchange resin extraction and 31P-NMR spectroscopy of dialysed NaOH extracts were used to investigate the effects of land use (Taubenberg, Bavaria: spruce forest, deciduous forest, permanent grass, arable) and fertilization (Askov, Denmark: unmanured, mineral fertilizer, animal manure) on forms of phosphorus in soil with emphasis on the potentially labile organic (Po) and inorganic (Pi) pools. Carbon content ranged from 12.5-118.1 g kg-1 and total P (Pi) content from 511 to 2063 mg kg-1. For all soils, the C:Po ratios of SOM decreased in the order: whole soil, 150:1-44:1; alkali extract, 57:1-41:1; resin extract, 20:1-9:1; suggesting an increasing P functionality of the OM with increasing Po lability. Analysis of functional relation showed a close relation between resin Po and 31P-NMR estimates for diester-P including teichoic acid-P, indicating that these species contributed significantly to the labile Po pool as determined by the resin method. The most marked effects of land-use were an increase in Pi under grass and arable, a concurrent sequestration of Po and SOM under grass, and a depletion of Po under arable. The amount of resin Pi appeared to be a function primarily of fertilization, and amounted to around 100 mg kg-1 in the fertilized soils irrespective of the SOM content and P source. The forest soil and the unfertilized agricultural soil had much smaller resin Pi values. The soil under grass had the largest amounts in resin Po and diester-P including teichoic acid-P, indicating a rapid turnover of Po with build-up of a large potentially labile, microbially derived Po pool. 31P NMR also showed large proportions of labile Po species in soils where microbial activity is restrained by acidity (Taubenberg spruce forest, phosphonates) or where highly microbially altered OM is relatively enriched (Taubenberg arable, diester-P including teichoic acid-P). We conclude that the resin used in this study isolates a structurally and functionally reasonably uniform pool of potentially labile soil Po.

External Organisation(s)
University of Bayreuth
Aarhus University
Type
Article
Journal
European journal of soil science
Volume
47
Pages
605-614
No. of pages
10
ISSN
1351-0754
Publication date
12.1996
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Soil Science
Sustainable Development Goals
SDG 2 - Zero Hunger, SDG 15 - Life on Land
Electronic version(s)
https://doi.org/10.1111/j.1365-2389.1996.tb01859.x (Access: Closed)