Elevated CO2 improved soil nitrogen mineralization capacity of rice paddy

Qicong Wu; Congzhi Zhang; Xuequan Liang; Chunwu Zhu; Tingyun Wang; Jiabao Zhang

doi:10.1016/j.scitotenv.2019.136438

Elevated CO₂ improved soil nitrogen mineralization capacity of rice paddy

Sci Total Environ. 2020 Mar 25:710:136438. doi: 10.1016/j.scitotenv.2019.136438. Epub 2019 Dec 31.

Authors

Qicong Wu¹, Congzhi Zhang², Xuequan Liang³, Chunwu Zhu², Tingyun Wang¹, Jiabao Zhang⁴

Affiliations

¹ State Experimental Station of Agro-ecosystem in Fengqiu, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, People's Republic of China; Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, People's Republic of China.
² State Experimental Station of Agro-ecosystem in Fengqiu, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, People's Republic of China.
³ Bureau of Natural Resources of Tongyu County, Baicheng City, Jilin Province, 137200, People's Republic of China.
⁴ State Experimental Station of Agro-ecosystem in Fengqiu, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, People's Republic of China. Electronic address: jbzhang@issas.ac.cn.

PMID: 31923701
DOI: 10.1016/j.scitotenv.2019.136438

Abstract

Elevated CO₂ would increase rice yields and may lead to nitrogen limitation and potentially influence the sustainability of agricultural production. Blindly increasing the amount of chemical fertilizer will damage the environment and is very unwise. Therefore, clarifying the response of soil nitrogen mineralization capacity to elevated CO₂ is critical for both sustainable agriculture production and environmental protection. Here, we relied on Free-Air CO₂ Enrichment (FACE) platform and used a waterlogged incubation method to investigate the effects of elevated CO₂ on soil nitrogen mineralization capacity under different fertilization levels when planted different rice cultivars (strong and weak-CO₂ response rice). According to the first-order kinetic equation fitting, compared with Ambient, elevated CO₂ increased soil potential mineralized nitrogen (N_p) by 16.18%. Path analysis indicated that fertilization status, rice cultivar, soil organic carbon and soil C: N ratio might affect N_p. There was a significant positive correlation between soil nitrogen mineralization rate and N_p. Under different fertilization conditions and rice cultivars, the improvement degree of soil nitrogen mineralization capacity (Np and soil nitrogen mineralization rate) by elevated CO₂ was different. These findings suggest that more parameters and influencing factors should be taken into account when studying soil nitrogen cycle models under the condition of global change.

Keywords: C: N; Free-air CO(2) enrichment; Paddy soil; Soil potential mineralized nitrogen.