Short-term biochar manipulation of microbial nitrogen transformation in wheat rhizosphere of a metal contaminated Inceptisol from North China plain

Huimin Zhou; Pan Wang; De Chen; Gaoling Shi; Kun Cheng; Rongjun Bian; Xiaoyu Liu; Xuhui Zhang; Jufeng Zheng; David E Crowley; Lukas van Zwieten; Lianqing Li; Genxing Pan

doi:10.1016/j.scitotenv.2018.06.009

Short-term biochar manipulation of microbial nitrogen transformation in wheat rhizosphere of a metal contaminated Inceptisol from North China plain

Sci Total Environ. 2018 Nov 1:640-641:1287-1296. doi: 10.1016/j.scitotenv.2018.06.009. Epub 2018 Jun 7.

Authors

Huimin Zhou¹, Pan Wang², De Chen², Gaoling Shi³, Kun Cheng², Rongjun Bian², Xiaoyu Liu², Xuhui Zhang², Jufeng Zheng², David E Crowley⁴, Lukas van Zwieten⁵, Lianqing Li², Genxing Pan⁶

Affiliations

¹ Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
² Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
³ Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
⁴ Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; Department of Environmental Science, University of California Riverside, CA 92521, USA.
⁵ Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; NSW Department of Primary Industries, 1243 Bruxner Highway, Wollongbar, NSW 2477, Australia.
⁶ Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: gxpan@njau.edu.cn.

PMID: 30021295
DOI: 10.1016/j.scitotenv.2018.06.009

Abstract

While metal immobilization had been increasingly reported with biochar soil amendment (BSA), changes in microbial activity and nitrogen (N) transformation in metal contaminated croplands following biochar addition had been insufficiently addressed. In a field experiment, a Pb/Cd contaminated Inceptisol from North China was amended to topsoil with wheat straw biochar at 0 (CK), 20 (C1) and 40 t ha^-1 (C2). The changes within two years following BSA were tested in microbial biomass and respiration, and in abundance of N transforming microbial communities and their activities. Corresponding to the results of decreased soil extractable Cd and Pb, significant reductions in qCO₂ were found in rhizosphere and bulk soil only under C2 in the first year. The potential nitrification activity was significantly increased by 20-71%, along with an increase in ammonium (by 7-21%) and nitrate (by 21%-70%) concentration, with BSA compared to CK. Meanwhile, N₂O production activity was slightly increased (by up to 20%) but N₂O reduction activity greatly enhanced (by up to 84%), with a higher ratio of nosZ/(nirS + nirK), under C2 in rhizosphere in both wheat seasons. Whereas, such changes were not remarkable in bulk soil. Moreover, microbial communities were less respondent to biochar in the second year following the addition. Therefore, microbial growth and functioning for N transforming and cycling in metal contaminated soils could be largely improved with BSA at 40 t ha^-1. Of course, studies are still deserved to mimic the long term changes with biochar in N cycling of the metal contaminated dry croplands.

Keywords: Biochar soil amendment; Heavy metal; Rhizosphere; Soil microbial community; Soil nitrogen transformation; Wheat cropland.

MeSH terms

Biodegradation, Environmental
Charcoal*
China
Metals / metabolism*
Nitrogen / metabolism*
Rhizosphere*
Soil
Soil Microbiology*
Soil Pollutants / metabolism*
Triticum

Substances

Metals
Soil
Soil Pollutants
biochar
Charcoal
Nitrogen