Silicon as a potential limiting factor for phosphorus availability in paddy soils

Title data

Schaller, Jörg ; Wu, Bei ; Amelung, Wulf ; Hu, Zhengyi ; Stein, Mathias ; Lehndorff, Eva ; Obst, Martin:
Silicon as a potential limiting factor for phosphorus availability in paddy soils.
In: Scientific Reports. Vol. 12 (2022) . - 16329.
ISSN 2045-2322
DOI: https://doi.org/10.1038/s41598-022-20805-4

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Abstract in another language

Rice cultivation requires high amounts of phosphorus (P). However, significant amounts of P fertilizer additions may be retained by iron (Fe) oxides and are thus unavailable for plants. At the same time, rice cultivation has a high demand for silicic acid (Si), reducing Si availability after short duration of rice cultivation. By studying a paddy chronosequence with rice cultivation up to 2000 years, we show that Si limitation, observed as early as a few decades of rice cultivation, is limiting P availability along the paddy soils chronosequence. Using near edge X-ray absorption fine structure spectroscopy (NEXAFS) in a scanning transmission (soft) X-ray microscope (STXM) we show release of available P was linked to a Si-induced change in speciation of Fe-phases in soil particles and competition of Si with P for binding sites. Hence, low Si availability is limiting P availability in paddy soils. We propose that proper management of Si availability is a promising tool to improve the P supply of paddy plants.