Fertilization regimes and the nitrification process in paddy soils

Lessons for agricultural sustainability from a meta-analysis

authored by
Xiangtian Meng, Haiyang Yu, Xuechen Zhang, Yaying Li, Kazem Zamanien, Huaiying Yao
Abstract

Increasing evidence shows that fertilization plays a key role in improving nitrogen (N) storage and increasing N supply capacity in paddy soils. How fertilizer regimes (N application rate, substitution rate, and fertilizer type) and environmental variables (soil pH and SOM) affect N pools, nitrification processes (abundance of nitrifying microorganisms, nitrification rate), and N losses (NH3 volatilization and N2O emission) in paddy soils is still unclear. Here, we conducted a meta-analysis by compiling a total of 1307 individual experimental observations from 64 peer-reviewed publications to evaluate the impacts of N fertilization with other amendments (manure, biochar, or nitrification inhibitors) on the abovementioned paddy soil N sequestration and turnover. Overall, fertilization increased N pools (total N, NH4+-N, and NO3-N content) and the abundance of main nitrifying microorganisms (AOA and AOB) by 7.3 % to 51.4 % and 70.3 % to 146.9 % in paddy soil, respectively, while stimulating NH3 volatilization and N2O emissions by 277.3 % and 149.7 %, respectively. The increased N losses following fertilization were positively correlated with the expansion of paddy soil N pools. In particular, the substitution of organic fertilizer for chemical fertilizer at 30 % to 70 % had a better effect on elevating soil N sequestration, while a substitution rate of >70 % reduced N losses. Moreover, the application of biochar and nitrification inhibitors was conducive to increasing total N, NH4+-N, and NH3 volatilization and reducing N2O emissions in fertilized paddy soils. Our findings indicated that fertilization regimes substantially stimulated N pools and N losses in paddy ecosystems. Thus, to avoid environmental and economic consequences, the optimization of N management and adjusting soil properties should be considered to increase N use efficiency and suppress N losses.

Organisation(s)
Institute of Soil Science
External Organisation(s)
Chinese Academy of Sciences (CAS)
Haixi Institutes of Chinese Academy of Sciences and People's Government of Beilun District
Northwest Agriculture and Forestry University
Wuhan Institute of Technology
Type
Article
Journal
Applied soil ecology
Volume
186
ISSN
0929-1393
Publication date
06.2023
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Ecology, Agricultural and Biological Sciences (miscellaneous), Soil Science
Sustainable Development Goals
SDG 2 - Zero Hunger
Electronic version(s)
https://doi.org/10.1016/j.apsoil.2023.104844 (Access: Closed)