Nitrogen application increases phytolith carbon sequestration in degraded grasslands of North China. Issue 1 (13th November 2015)

• Record Type: Journal Article
• Authors: Zhao, Yuying; Song, Zhaoliang; Xu, Xiaotian; Liu, Hongyan; Wu, Xiuchen; Li, Zimin; Guo, Fengshan; Pan, Wenjie
• Is Part Of: Ecological research. Volume 31:Issue 1(2016)
• Page Start: 117
• Page End: 123
• Publication Date: 2015-11-13
• Subjects: Phytoliths -- Nitrogen application -- PhytOC -- Degraded grasslands -- Carbon sequestration; Ecology -- Periodicals; Ecology -- Japan -- Periodicals; Écologie; Japon; Ecology; Japan; Ressource Internet (Descripteur de forme); Périodique électronique (Descripteur de forme); Periodicals; 577.05
• DOI: 10.1007/s11284-015-1320-0
• Languages: English
• ISSNs: 0912-3814

Abstract

Abstract: Phytolith‐occluded carbon (PhytOC) has significant potential for long‐term biogeochemical carbon (C) sequestration because of its high resistance against decomposition. It may also play a crucial role in slowing the increase in global CO2 concentrations and mitigating climate warming. As phytolith C sequestration flux is usually correlated with phytolith content, C content of phytoliths and above‐ground net primary productivity in plants, we hypothesize that application of fertilizers may increase phytolith C sequestration in some degraded grasslands. In this study, we conducted a field experiment to investigate the effects of external application of nitrogen (N) at six levels (0, 10, 20, 30, 40, and 50 g N m −2 year −1 ) from 2011 to 2013 on the potential for phytolith C sequestration in degraded grasslands. Analysis showed that N application increased the PhytOC production flux in the extremely degraded grassland from 0.003 to 0.021 t CO2 ha −1 year −1 and the flux increased with the level of N fertilization peaking in the 20 g N m −2 year −1 treatment at 700 % of the control flux, but decreased at higher N doses. Assuming half of China's grasslands are fertilized with N to recover from degradation and the phytolith C sequestration flux of degraded grasslands amended with N is half of the 700 % increase, the potential of phytolith C sequestration in China's grasslands could be increased at least 60 %. This study demonstrates that optimization of nutritional supply is a promising approach to increase long‐term phytolith C sequestration in degraded grasslands.