Supraparticles as slow-release fertiliser in seedling potential growth of Eucalyptus urograndis and greenhouse gas flux impacts

Abstract

Slow-release urea fertilisers have been shown to present acceptable values for plant yield and mitigate the harmful effect of soil emission gases. This study synthesises a slow-release fertiliser containing fumed-nanosilica, nanofibrillated cellulose as well as sodium alginate as a urea carrier to analyse the growth parameters of Eucalyptus urograndis seedlings and potential emission of soil gases, N2O, CH4, CO2 and ammonia volatilisation. The developed supraparticles, arranged layered nanoparticle structure, presented a decrease in the normal nitrogen content of urea of 19%, which is attributed to the binding of this element. A good electrostatic interaction between the elements was confirmed by the FTIR with 20% of nitrogen content from its chemical composition and an increase in thermal degradation of the main components when synthesised. The profile of urea release presented to be as first-order with 85% of urea release in the first 24 h and complete release after 15 days. The seedling experiment showed a positive effect on the growth parameters of Eucalyptus urograndis with a higher height and biomass accumulation of the stem and roots compared to the control group. In addition, the results indicate that the supraparticles decreased the soil emissions of N2O, CH4, and CO2 gases and ammonia volatilisation, which suggests a potential for use in agriculture for mitigating greenhouse gas emissions.