Estimated Carbon Sequestration by Rice Roots as Affected by Silicon Fertilizers

Resumo

One of the most relevant tasks of modern agriculture is developing and implementing fundamentally new, available, environmentally safe “nature-like” technologies, providing a “sink” of carbon or a significant reduction in greenhouse gas emissions in all the agricultural landscapes, including those engaged in rice cultivation. In field trials conducted in Hunan province (China), the influence of silicon fertilizers on CO₂ sequestration by rice plant roots was estimated. Its value depends on the content of available silicon in agrochemicals, on frequency and duration of their use, and on soil texture. The data obtained indicate the important role of silicon fertilizers in the processes of carbon sequestration and reduction of greenhouse gas emissions in rice cultivation. Their application results in increased crop yields by 12.1–71.2% and increased CO₂ sequestration by plant roots by 0.95–14.9 t ha^–1 in one season. Soil carbon recovery and soil fertility reproduction can be ensured by intensive development of the plant root system and by an increase in root residues’ mass after harvest. Agrochemicals containing silicon available for plants should be included in the 4R-strategy for mineral nutrition of agricultural crops.