Nitrogen addition increased soil particulate organic carbon via plant carbon input whereas reduced mineral-associated organic carbon through attenuating mineral protection in agroecosystem

Tao Sun; Xiali Mao; Kefeng Han; Xiangjie Wang; Qi Cheng; Xiu Liu; Jingjie Zhou; Qingxu Ma; Zhihua Ni; Lianghuan Wu

doi:10.1016/j.scitotenv.2023.165705

Nitrogen addition increased soil particulate organic carbon via plant carbon input whereas reduced mineral-associated organic carbon through attenuating mineral protection in agroecosystem

Sci Total Environ. 2023 Nov 15:899:165705. doi: 10.1016/j.scitotenv.2023.165705. Epub 2023 Jul 22.

Authors

Tao Sun¹, Xiali Mao¹, Kefeng Han¹, Xiangjie Wang¹, Qi Cheng¹, Xiu Liu¹, Jingjie Zhou¹, Qingxu Ma¹, Zhihua Ni², Lianghuan Wu³

Affiliations

¹ Ministry of Education Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
² Cultivated Land Quality and Fertilizer Management Station of Zhejiang Province, Hangzhou 310020, China. Electronic address: hznzh@163.com.
³ Ministry of Education Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China. Electronic address: finm@zju.edu.cn.

PMID: 37487902
DOI: 10.1016/j.scitotenv.2023.165705

Abstract

Nitrogen (N) addition can have substantial impacts on both aboveground and belowground processes such as plant productivity, microbial activity, and soil properties, which in turn alters the fate of soil organic carbon (SOC). However, how N addition affects various SOC fractions such as particulate organic carbon (POC) and mineral-associated organic carbon (MAOC), particularly in agroecosystem, and the underlying mechanisms remain unclear. In this study, plant biomass (grain yield, straw biomass, and root biomass), soil chemical properties (pH, N availability, exchangeable cations and amorphous Al/Fe - (hydr) oxides) and microbial characteristics (biomass and functional genes) in response to a N addition experiment (0, 150, 225, 300, and 375 kg ha^-1) in paddy soil were investigated to explore the predominant controls of POC and MAOC. Our results showed that POC significantly increased, while MAOC decreased under N addition (p < 0.05). Correlation analysis and PLSPM results suggested that increased C input, as indicated by root biomass, predominated the increase in POC. The declined MAOC was not mainly dominated by microbial control, but was strongly associated with the attenuated mineral protection (especially Ca²⁺) induced by soil acidification under N addition. Collectively, our results emphasized the importance of combining C input and soil chemistry in predicting soil C dynamics and thereby determining soil organic C storage in response to N addition in rice agroecosystem.

Keywords: Mineral protection; Mineral−associated organic carbon; Nitrogen addition; Particulate organic carbon; Soil acidification.

MeSH terms

Carbon* / analysis
Dust / analysis
Edible Grain / chemistry
Minerals
Nitrogen / analysis
Soil Microbiology
Soil* / chemistry

Substances

Soil
Carbon
Nitrogen
Dust
Minerals