Warming and elevated CO₂ interactively affect the photosynthetic carbon of maize plant retained in major farming soils

ABSTRACT

Warming and elevated CO₂ (eCO₂) may influence the input of photosynthetic carbon (C) into soils and subsequent soil C storage. The biochemical properties vary among soils, which likely act different roles in the fate of photosynthetic C and soil C sequestration in response to warming and eCO₂. However, the interactive effects of climate change and soil types on the photosynthetic C retained in soil and relevant mechanisms are poorly understood. We performed a pot experiment in open-top chambers to examine the effects of eCO₂ (550 ppm) combined with elevated temperature (eT, 2 °C higher than the air temperature) on the retention of plant-C of maize (Zea mays L.) grown in Phaeozem, Fluvisol, Kastanozem and Acrisol with ¹³CO₂ labeling at the silking stage. The proportion of ¹³C to the total fixed ¹³C increased by 44.6%, 96.1% and 41.9% in Phaeozem under eT, eCO₂ and eT plus eCO₂ treatments compared with control, while decreased in other three soils in response to either eCO₂, eT or eT plus eCO₂. The effect of climate change on fresh C input in maize cropping soils depended on soil type, and soil net C losses may occur in the Fluvisol, Kastanozem and Acrisol under climate change.

Abbreviations: eCO₂: elevated CO₂, 550ppm; eT: warming; aCO₂: ambient CO₂, 400ppm; aT: ambient temperature; OTC: open-top chamber; DOC: dissolved organic carbon; SOC: soil organic carbon; C: carbon; S: soil; T: temperature.

KEYWORDS:

• Climate change
• open top chamber
• carbon input
• soil types
• Zea mays L

Disclosure Statement

No potential conflict of interest was reported by the authors.

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Additional information

Funding

The project was funded by the National Key Research and Development Program of China (2017YFD0300300), the National Natural Science Foundation of China （41771326）, La Trobe University Research Focus Area (RFA) project (2000002982), and “Touyan” Program of Heilongjiang province.We much appreciate that Professor Chunxia Xu at the Institute of Food Crops (IFC), Yunnan Academy of Agriculture Science (YAAS) and Professor Zhijun Su at Inner Mongolia University kindly provided soils for this experiment.