EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Anthropogenic desilication of agricultural soils – Results from a long-term field experiment in NE Germany

Daniel Puppe1, Danuta Kaczorek1,2, and Michael Sommer1,3
Daniel Puppe et al.
  • 1Leibniz Centre for Agricultural Landscape Research, Müncheberg, Germany (
  • 2SGGW - Warsaw University of Life Sciences, Division of Soil Science, Warsaw, Poland
  • 3University of Potsdam, Institute of Geography and Environmental Science, Potsdam, Germany

Due to intensified land use (agriculture, forestry) humans directly influence silicon (Si) cycling on a global scale. In this context, especially Si exports by harvested crops (most of them are Si accumulators) and increased erosion rates generally lead to a Si loss in agricultural soils (anthropogenic desilication). Harvesting of field crops can cause Si losses of up to 100 kg Si ha-1 per year. On a global scale about 35% of total phytogenic Si is synthesized by field crops due to their relatively high Si contents as well as biomasses and this proportion is going to increase with increased agricultural production within the next decades. In order to avoid (natural) limitations of plant available Si and enhance plant growth and resistance against abiotic and biotic stresses, Si fertilization is widely used, especially in (sub)tropical agricultural systems. In this context, specific Si fertilization, for example, in the form of recycled organic siliceous materials (e.g., straw, biochar), might be a promising strategy for both increasing crop yields and decreasing desilication of agricultural soils. However, most studies focus on rice and sugarcane production and there is still only little knowledge about Si cycling in agricultural systems of the temperate zone. We analyzed soil and plant samples from an ongoing long-term field experiment (established 1963, randomized block design: plots with low, medium, and high mineral NPK fertilization rates, plots with straw fertilization in addition to NPK fertilization, control plots) in NE Germany to answer the following questions: (i) Can we observe a significant desilication (indicated by a decrease in plant available Si in soils) of agricultural systems in the temperate zone in the long term?, (ii) Is this potential desilication affected by NPK fertilization rates?, (iii) Is this potential decrease of plant available Si in soils reflected in Si concentrations of the grown plants (e.g., wheat)?, and (iv) Can we prevent potential anthropogenic desilication by straw fertilization? Here we present our first results to answer these questions. The answers to these questions will help us to obtain a deeper understanding of Si cycling in agricultural biogeosystems in the temperate zone in general and to derive practice-oriented recommendations for a more environmentally friendly and sustainable crop production in particular.

How to cite: Puppe, D., Kaczorek, D., and Sommer, M.: Anthropogenic desilication of agricultural soils – Results from a long-term field experiment in NE Germany, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8241,, 2020


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  • CC1: Comment on EGU2020-8241, Harold Hughes, 07 May 2020

    Dear Daniel and colleagues, 
    Thank you for this interesting results. 
    I have a very simple technical question: Since most people usually prefer to avoid working with HF when possible, are there specific reasons why you quantified the Si in plants with a HF extraction rather than with an alkaline extraction ? (NaOH for example) Is it just because you already had the HF extraction proceedure implemented in the laboratory or is there a more fundamental reason ?



    • AC1: Reply to CC1, Daniel Puppe, 07 May 2020

      Dear Harold,

      Thanks a lot for your interest in our research and your question.

      Actually, we used the HF extraction, because it is the established method in our lab, yes. However, we already planned to compare our HF extraction to alkaline extraction methods as these are quite common in Si analyses.

      I will let you know when our results will be available.


      I hope my answer finds you well,

      best wishes,


      • CC2: Reply to AC1, Harold Hughes, 07 May 2020

        Dear Daniel,

        Thank you for your reply. Yes, I would be interested to hear about the results of your comparison. Both methods are widely used and have been tested separately, but indeed as far as I know, never compared directly against each other.

        Best regards,


        • AC2: Reply to CC2, Michael Sommer, 07 May 2020

          We started with HF over 10 years ago to assure a full dissolution of any biogenic Si. So, for comparison with old data (at least in our lab) we stick to HF up to now. Anyhow, if we get a close relationship with alkaline extracts along the 1:1 line we might shift to those extractants. If it is a very good correlation between both extractants but below or above the 1:1 line we will check what material is left undissolved by SEM-EDX. Our test sample will consist of approx. 30 different plants (organs), showing a huge range of Si contents (3 orders of magnitude) as well as (supposed) phytoliths types, sizes etc.

          By the way: I have a bet (crate of beer) with Jörg about the results...