Plant and Soil

, Volume 352, Issue 1, pp 173–184

Long-term removal of wheat straw decreases soil amorphous silica at Broadbalk, Rothamsted

Authors

  • Flore Guntzer
    • CEREGE CNRS/Aix-Marseille Université, Europôle Méditerranéen de l′Arbois
    • CEREGE CNRS/Aix-Marseille Université, Europôle Méditerranéen de l′Arbois
  • Paul R. Poulton
    • Rothamsted Research
  • Steve P. McGrath
    • Rothamsted Research
    • CEREGE CNRS/Aix-Marseille Université, Europôle Méditerranéen de l′Arbois
Regular Article

DOI: 10.1007/s11104-011-0987-4

Cite this article as:
Guntzer, F., Keller, C., Poulton, P.R. et al. Plant Soil (2012) 352: 173. doi:10.1007/s11104-011-0987-4

Abstract

Aims

Most cereals accumulate Si in their shoots. Soil bioavailability of Si may be a constraint on the beneficial role of silica in cereals but it is not yet well supported by field data. The aim of this study is to evaluate the long-term impact of wheat straw exports on the pool of soil phytoliths, which, it is suggested, represents the most labile and renewable pool of soil Si.

Methods

We measured the amorphous Si (ASi) in soils from several experiments at Rothamsted Research (UK), which provided long-term soil data back to the middle of the 19th century, using two alternative extraction techniques: Na2CO3 (referred to as ASnc) or zinc bromide extraction (referred to as ASizb).

Results

All samples showed a similar range of ASnc and ASizb but low values (0.1–3.4 mg g−1 DW) compared to published data on natural ecosystems. In the Broadbalk experiment, a decrease over time in ASi in the topsoil samples is in good agreement with the hypothesis that cropping and exports of straw leads to depletion of soil phytoliths. A decrease in Si concentration in straw samples was observed between 1883 and 1944. From 1944 to the present, Si concentration increased irregularly in the straw, probably as the result of liming, which enhanced the dissolution of the remaining phytoliths through increasing pH. In the reforested Geescroft field the higher phytolith concentration in the modern topsoil samples is in good agreement with a re-building of phytolith storage from litter input in an acidic environment.

Conclusions

Our results therefore support the hypothesis that export of wheat straw leads to a decrease in bioavailable Si.

Keywords

Phytolith Silicon Bioavailability Cereals Sustainability

Copyright information

© Springer Science+Business Media B.V. 2011