Amendment of straw with decomposing inoculants benefits the ecosystem carbon budget and carbon footprint in a subtropical wheat cropping field

Cheng Ji; Jidong Wang; Cong Xu; Yian Gu; Jie Yuan; Dong Liang; Lei Wang; Yunwang Ning; Jie Zhou; Yongchun Zhang

doi:10.1016/j.scitotenv.2024.171419

Amendment of straw with decomposing inoculants benefits the ecosystem carbon budget and carbon footprint in a subtropical wheat cropping field

Sci Total Environ. 2024 May 1:923:171419. doi: 10.1016/j.scitotenv.2024.171419. Epub 2024 Mar 4.

Authors

Cheng Ji¹, Jidong Wang², Cong Xu¹, Yian Gu³, Jie Yuan⁴, Dong Liang⁴, Lei Wang⁴, Yunwang Ning⁴, Jie Zhou⁵, Yongchun Zhang¹

Affiliations

¹ National Agricultural Experimental Station for Agricultural Environment, Luhe, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
² National Agricultural Experimental Station for Agricultural Environment, Luhe, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China. Electronic address: Jidongwang@jaas.ac.cn.
³ College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China.
⁴ National Agricultural Experimental Station for Agricultural Environment, Luhe, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
⁵ College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.

PMID: 38442752
DOI: 10.1016/j.scitotenv.2024.171419

Abstract

The incorporation of straw with decomposing inoculants into soils has been widely recommended to sustain agricultural productivity. However, comprehensive analyses assessing the effects of straw combined with decomposing inoculants on greenhouse gas (GHG) emissions, net primary production (NPP), the net ecosystem carbon budget (NECB), and the carbon footprint (CF) in farmland ecosystems are scant. Here, we carried out a 2-year field study in a wheat cropping system with six treatments: rice straw (S), a straw-decomposing Bacillus subtilis inoculant (K), a straw-decomposing Aspergillus oryzae inoculant (Q), a combination of straw and Bacillus subtilis inoculant (SK), a combination of straw and Aspergillus oryzae inoculant (SQ), and a control with no rice straw or decomposing inoculant (Control). We found that all the treatments resulted in a positive NECB ranging between 838 and 5065 kg C ha^-1. Relative to the Control, the S treatment increased CO₂ emissions by 16%, while considerably enhancing the NECB by 349%. This difference might be attributed to the straw C input and an increase in plant productivity (NPP, 30%). More importantly, in comparison to that in S, the NECB in SK and SQ significantly increased by 27-35% due to the positive response of NPP to the decomposing inoculants. Although the combination of straw and decomposing inoculants yielded a 3% increase in indirect GHG emissions, it also exhibited the lowest CF (0.18 kg CO₂-eq kg^-1 of grain). This result was attributed to the synergistic effects of straw and decomposing inoculants, which reduced direct N₂O emissions and increased wheat productivity. Overall, the findings of the present study suggested that the combined amendment of straw and decomposing inoculants is an environmentally sustainable management practice in wheat cropping systems that can generate win-win scenarios through improvements in soil C stock, crop productivity, and GHG mitigation.

Keywords: Carbon footprint; Ecosystem carbon budget; Microbial inoculant; Straw.

MeSH terms

Agriculture / methods
Carbon Dioxide / analysis
Carbon Footprint
Carbon*
China
Ecosystem
Greenhouse Gases*
Nitrous Oxide / analysis
Soil
Triticum

Substances

Carbon
Carbon Dioxide
Nitrous Oxide
Soil
Greenhouse Gases