Acceleration of straw-nitrogen mineralization under co-elevation of CO2 and temperature is associated with microbial attributes in the rhizosphere of rice
Jinyuan Zhang,
Zhenhua Yu,
Yansheng Li,
Xinqi Sima,
Guanghua Wang,
Xiaobing Liu,
Caixian Tang,
Junjie Liu,
Judong Liu,
Xiaojing Hu,
Stephen J. Herbert,
Jian Jin
Affiliations
Jinyuan Zhang
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
Zhenhua Yu
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
Yansheng Li
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
Xinqi Sima
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China; University of Chinese Academy of Sciences, Beijing 100049, China
Guanghua Wang
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
Xiaobing Liu
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
Caixian Tang
La Trobe Institute for Sustainable Agriculture & Food, Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC 3083, Australia
Junjie Liu
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
Judong Liu
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
Xiaojing Hu
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
Stephen J. Herbert
Center for Agriculture, University of Massachusetts, Amherst, MA 01003, USA
Jian Jin
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China; La Trobe Institute for Sustainable Agriculture & Food, Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC 3083, Australia; Corresponding author at: La Trobe Institute for Sustainable Agriculture & Food, La trobe University; State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences.
Quantifying the straw-nitrogen (N) in soil N pools and exploring soil microbial phylogenetic diversity involved in N mineralization are important for effectively managing crop straw to optimize crop N use under climate change. This study used 15N-labeled rice straw to quantify straw-N mineralization in the rhizosphere and N uptake of rice plants in response to elevated CO2 (700 ppm) and warming (2 °C above ambient). The CO2 and temperature co-elevation resulted in 20 mg kg−1 of straw-N mineralized in the rhizosphere, 50 % greater than the ambient control. A similar trend was found for soil-N mineralization. The CO2 and temperature co-elevation significantly increased the gaseous loss of straw-derived N from the rhizosphere, and straw-N in microbial biomass fraction, soluble organic and mineral N fractions in bulk soil. It also increased microbial biomass N originated from the rhizosphere soil. Irrespective of climatic treatments, the amount of mineralized N from straw and soil was greater in the rhizosphere than bulk soil. The CO2 and temperature co-elevation increased plant N uptake by 32 % with the dominant origin of soil-N rather than straw-N. With straw amendment, elevated CO2 plus warming significantly (p < 0.05) increased the abundance of leucine aminopeptidase (pepA) gene. The abundances of pepA, urease (ureC) and chitinase (chiA) genes were lower in the rhizosphere than in the bulk soil. Elevated CO2 plus warming significantly (p < 0.05) altered urease (ureC) and leucine aminopeptidase (pepA)-relevant community compositions in both rhizosphere and bulk soils, which were in turn associated with the N mineralization. The results suggest that the climate-change-induced shift of the composition rather than gene abundances of microbial communities that are involved in ammonification contributes to faster mineralization of soil N and straw N in paddy soils.
