Geoderma (Feb 2024)
Silicon fertiliser application increases the terrestrial ecosystem carbon pool at the global scale
Abstract
Silicon fertilisers are widely utilised to achieve higher productivity in global terrestrial ecosystems, but their impact on the carbon cycle remains unclear. In this study, we used a meta-analysis approach to quantify the response of carbon pools and fluxes in terrestrial ecosystems worldwide to the application of silicon fertiliser while also investigating the factors influencing this response. The findings indicated that silicon fertiliser application led to significant increases in various carbon components: plant aboveground carbon increased by 22.9%, plant belowground carbon increased by 17.3%, litter carbon increased by 8.3%, and the SOC content increased by 8.6%. Furthermore, the net photosynthetic rate of plants was significantly enhanced by 28.1% through the application of silicon fertiliser, along with a notable increase of 36.9% in the net primary productivity of ecosystems, which exhibited a strong correlation with alterations in ecosystem carbon pools. A considerable reduction of 29.6% in soil CH4 emissions was observed, whereas the influence of silicon fertiliser on the litter decomposition rate and net soil CO2 emissions was not statistically significant. Moreover, fertilisation (such as vegetation and soil types), climatic conditions, and silicon fertiliser application techniques have been found to affect the responses of carbon pools and fluxes to silicon fertiliser application. Finally, a potential mechanism by which silicon fertilisation can affect plant growth, litterfall, soil organic carbon stability, and soil carbon emissions directly and indirectly by changing the available silicon and soil pH is proposed to explain the positive effects of silicon fertiliser application on terrestrial ecosystem carbon pools. This effect may change owing to the influence of fertilisation technology, fertilisation, climate, and other factors.
