Citric acid modified biochar application at a low dosage can synchronically mitigate the nitrogenous gas pollutants emission from rice paddy soils

Haijun Sun; Zhenghua Yi; Paramsothy Jeyakumar; Changlei Xia; Yanfang Feng; Su Shiung Lam; Christian Sonne; Hailong Wang; Weiming Shi

doi:10.1016/j.envpol.2022.120068

Citric acid modified biochar application at a low dosage can synchronically mitigate the nitrogenous gas pollutants emission from rice paddy soils

Environ Pollut. 2022 Nov 1:312:120068. doi: 10.1016/j.envpol.2022.120068. Epub 2022 Aug 31.

Authors

Haijun Sun¹, Zhenghua Yi², Paramsothy Jeyakumar³, Changlei Xia⁴, Yanfang Feng⁵, Su Shiung Lam⁶, Christian Sonne⁷, Hailong Wang⁸, Weiming Shi⁹

Affiliations

¹ Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China. Electronic address: hjsun@njfu.edu.cn.
² Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China. Electronic address: yizhenghua@njfu.edu.cn.
³ Environmental Sciences, School of Agriculture and Environment, Massey University, Palmerston North, 4442, New Zealand. Electronic address: P.Jeyakumar@massey.ac.nz.
⁴ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China. Electronic address: changlei.xia@njfu.edu.cn.
⁵ Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China. Electronic address: jaasfengyanfang@163.com.
⁶ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China; Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030, Kuala Nerus, Terengganu, Malaysia. Electronic address: lam@umt.edu.my.
⁷ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China; Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, DK-4000, Roskilde, Denmark. Electronic address: cs@bios.au.dk.
⁸ School of Environment and Chemical Engineering, Foshan University, Foshan, 528000, China. Electronic address: hailong.wang@fosu.edu.cn.
⁹ School of Food Science and Engineering, Foshan University, Foshan, 528000, China. Electronic address: wmshi@issas.ac.cn.

PMID: 36057329
DOI: 10.1016/j.envpol.2022.120068

Abstract

Raw biochar with high pH possibly stimulated ammonia (NH₃) volatilization in the agricultural soil. We hypothesized that the modified biochar (MBC) with low pH can synchronically decrease the NH₃ and nitrous oxide (N₂O) losses. We performed a two-year experiment to clarify how citric acid MBC influence the NH₃ volatilization and N₂O emission as well as the underlying mechanisms. Two typical paddy soils, i.e., Hydragric Anthrosol and Haplic Acrisol, receiving equal urea N with 240 kg ha^-1 but varied rates of MBC with 0, 5, 10, and 20 t ha^-1 (named Urea, Urea + MBC5, Urea + MBC10, and Urea + MBC20, respectively) were studied. The results showed that MBC-amended treatments effectively mitigated the NH₃ volatilization from Hydragric Anthrosol and Haplic Acrisol by 29.6%-57.9% and 30.5%-62.4% in 2017, and by 16.5%-21.0% and 24.5%-35.0% in 2018, respectively, compared to Urea treatment. In addition, significantly lower N₂O emissions with averaged 38.3% and 43.1% in 2017, and 51.7% and 26.7% were recorded under Hydragric Anthrosol and Haplic Acrisol, respectively, following the MBC application (P < 0.05). Increased MBC addition performed higher efficacy on mitigating NH₃ volatilization, particularly in the first rice season, while this "dosage effect" was not found for N₂O reduction. Lowered pH in overlying water, enhanced adsorption of NH₄⁺-N and its nitrification rate likely contributed to the lower NH₃ volatilization as result of MBC addition. The nirS and nosZ gene copies were not changed by MBC, while the nirK gene copies were decreased as result of MBC amendment by 8.3%-25.2% under Hydragric Anthrosol and by 21.8%-24.9% under Haplic Acrisol. Consequent lower ratio of nirK/(nirS + nosZ) explained the mitigation effect of MBC on N₂O emission. In conclusion, the present two-year study recommends that MBC applied at a low dosage can perform positive effect on controlling the nitrogenous gas pollutants from paddy soil.

Keywords: Ammonia volatilization; Biochar; N fertilizer; Nitrous oxide; nirK/(nirS + nosZ).

MeSH terms

Agriculture
Ammonia / analysis
Charcoal
Citric Acid
Environmental Pollutants*
Fertilizers / analysis
Gases
Nitrous Oxide / analysis
Oryza*
Soil
Urea
Water

Substances

Environmental Pollutants
Fertilizers
Gases
Soil
biochar
Water
Charcoal
Citric Acid
Ammonia
Urea
Nitrous Oxide