Abstract
Abstract CO2, a major cause of global warming, is also an important substrate for the crop photosynthesis. However, there are few data to explain the contribution of soil CO2 emission to crop photosynthesis. In order to separate the sources of CO2 involved in photosynthesis, stable isotope and Keeling plot methods were used under a long-term experiment. Under each condition, maize was covered by a chambers, among which three chambers were laid on the ground with 500 g Ca(OH)2 inside to absorb soil CO2 emissions (ck) and another three chambers did not contain Ca(OH)2. The results showed that A, gs, Tr and WUEi increased by 13.98, 12.81, 16.76 and 1.51%, however, δ13C, Ci/Ca, and WUEt decreased by 5.51, 8.57, and 3.56% than those in ck, respectively. The CO2 recycling index was 0.82–0.90, and the contribution of soil emissions to photosynthesis was 20.37%–29.03%. Thus, maize photosynthetic rate can be improved with higher soil carbon emission to the canopy. This process merits further study as to how to regulate soil emission to increase agronomic yield with less carbon emission in farmland.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
