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Nitrogen application increases phytolith carbon sequestration in degraded grasslands of North China
Author(s) -
Zhao Yuying,
Song Zhaoliang,
Xu Xiaotian,
Liu Hongyan,
Wu Xiuchen,
Li Zimin,
Guo Fengshan,
Pan Wenjie
Publication year - 2016
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1007/s11284-015-1320-0
Subject(s) - phytolith , carbon sequestration , biogeochemical cycle , grassland , environmental science , flux (metallurgy) , primary production , agronomy , carbon fibers , nitrogen , carbon sink , environmental chemistry , chemistry , ecology , biology , ecosystem , materials science , pollen , organic chemistry , composite number , composite material
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 CO 2 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 CO 2 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.