Distribution of soil phytolith-occluded carbon in the Chinese Loess Plateau and its implications for silica-carbon cycles

• Published in: Plant and soil Vol. 374; no. 1/2; pp. 223 - 232
• Main Authors: Zuo, XinXin, Lu, HouYuan, Gu, ZhaoYan
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.01.2014; Springer Netherlands; Springer Nature B.V
• Subjects: Agricultural soils; Agrology; Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Biogeochemical cycles; Biological and medical sciences; Biomedical and Life Sciences; biosequestration; Carbon content; Carbon cycle; Carbon cycle (Biogeochemistry); Carbon sequestration; Carbon sinks; China; Desert soils; Distribution; Ecology; Environmental aspects; Forest steppe soils; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Grassland soils; Life Sciences; Loess; Loess soils; Organic carbon; oxidation; Phytoliths; Plant communities; Plant Physiology; Plant Sciences; Plants; Regular Article; Rivers; Sedimentary soils; Silica; Soil erosion; Soil profiles; Soil research; Soil science; Soil Science & Conservation; Soil sciences; Soil testing; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Soils; Studies; Yellow River; Asia; China; Far east; India; China, People's Rep., Loess Plateau; China, People's Rep., Huang He R; Yellow River; Chinese Loess Plateau; PhytOC; Carbon sequestration; Silica cycle; Soil phytoliths; Loess; Phytolith; Opal; Silicon compound; Sediments; Carbon; Silica; Mineral matter; Inorganic compound; Carbon cycle; Soils; Geographical division; Distribution; Plant origin; Soil plant relation
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-013-1850-6

Background and aims Plants absorb and carry soluble silica from soils and then deposit SiO₂·nH₂O within themselves producing amorphous silica particles known as phytoliths. Trace amount of organic carbon is occluded during phytolith formation referred to as phytolith-occluded carbon (PhytOC). This carbon fraction has been recognized as an important way of carbon biosequestration. Previous studies have investigated the PhytOC contents of many crop plants and their contribution to global carbon sink. However, the PhytOC in soil is less focused. In this study, we investigated the distribution of soil PhytOC in the Chinese Loess Plateau (CLP). Methods Twenty-six soil profiles were collected in the Chinese Loess Plateau. A wet oxidation method was used for phytolith extraction. Occluded carbon was determined by element analyzer. Results Our results showed that the soil PhytOC density (SPCD) ranged from 0.757 to 23.110 g/m² among different soil profiles. The SPCD of profiles in the Southern CLP was generally higher than that in the Northern CLP. It was estimated that 5.35 Mt of PhytOC was stored in the upper soil of the CLP. We also estimated the annual phytolith flux into the Yellow River from the CLP by soil erosion and about 2.5 Mt of phytoliths eroded and transported into rivers per year. Conclusions Our study indicated that PhytOC was one of the potential biosequestration way and phytoliths had an important influence on biogeochemical cycle of silica. Our results suggested that the soil PhytOC was mainly influenced by different plant communities.