The regulation of gross nitrogen transformation rates in greenhouse soil cultivated with cucumber plants under elevated atmospheric [CO2] and increased soil temperature
Di Li,
Jinbo Zhang,
Nazim S. Gruda,
Ziying Wang,
Zengqiang Duan,
Christoph Müller,
Xun Li
Affiliations
Di Li
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
Jinbo Zhang
School of Geography, Nanjing Normal University, Nanjing 210023, China; Liebig Centre for Agroecology and Climate Impact Research, Justus Liebig University, 35392 Giessen, Germany
Nazim S. Gruda
Department of Horticultural Sciences, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn 53121, Germany
Ziying Wang
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
Zengqiang Duan
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
Christoph Müller
Institute of Plant Ecology, Justus Liebig University Giessen, Heinrich-Buff-Ring 26, 35392 Giessen, Germany; School of Biology and Environmental Science and Earth Institute, University College Dublin, Belfield, Dublin, Ireland; Liebig Centre for Agroecology and Climate Impact Research, Justus Liebig University, 35392 Giessen, Germany
Xun Li
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China; Corresponding author at: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Climate change scenarios forecast both increase in atmospheric CO2 concentration ([CO2]) and temperature. Elevated [CO2] (e[CO2]) and soil temperature (eST) significantly increased plant growth and nitrogen (N) uptake. However, studies on the combined effect of these factors on soil N transformation and microbial community are scarce in agricultural intensification. In the present work, we cultivated cucumber plants under e[CO2] or/and eST, followed by a paired labeling 15N tracer experiment (15NH4NO3 and NH415NO3) to quantify soil gross N transformation rates. Results showed that e[CO2] decreased soil gross N nitrification rate, indicated by a decline in ammonia-oxidizing bacteria (amoA-AOB) and nitrite oxidoreductase alpha subunit (nxrA) gene copy numbers, and changed microbial taxonomic composition under ambient soil temperature (aST). Furthermore, eST increased chitinase gene (chiA) and amoA-AOB gene copy numbers and alpha diversity and changed the microbial taxonomic composition to improve soil gross N mineralization and nitrification rates. The combination of e[CO2] and eST promoted soil gross N mineralization, nitrification, and immobilization rates compared with ambient [CO2] and aST. The study showed that the combination of e[CO2] and eST increased the primary gross N transformation rates and accelerated soil N circulation, which could ensure plant N demand. Therefore, combining e[CO2] and eST provided a promising way to help cultivators promote vegetable growth in winter, mitigate soil N loss, and achieve sustainable development in greenhouse vegetable cultivation.
