Agricultural Water Management
Agricultural Water Management
3 years ago

Deficit irrigation provokes more pronounced responses of maize photosynthesis and water productivity to elevated CO2

It is very significant to study the impact of deficit irrigation on crop growth and water use under the future scenarios with elevated CO2 concentrations and reduced water availability. This study investigated the growth and yield differences of maize grown in a phytotron in response to elevated CO2 concentrations under different irrigation treatments. Two irrigation treatments were carried out: regular irrigation (RI) and deficit irrigation (DI), in which the irrigation amounts were respectively 100 and 70% of evapotranspiration (ET), with four CO2 concentrations (400, 550, 700, and 900μmolmol−1). Thus eight treatments, i.e. RI400, RI550, RI700, RI900, DI400, DI550, DI700, and DI900 were included in this study. Results show that, the relative reductions of stomatal conductance (gs ) and transpiration rate (Tr ) in response to elevated CO2 concentrations were higher under DI than RI, thus causing leaf temperature (Tleaf ) rose higher under DI due to the transpiration cooling effect. As photosynthetic rate (Pn ) and its physiological process were positively correlated with Tleaf , the relative increases of Pn and the resulting maximum leaf area index (LAImax ), total dry matter weight (TDW), and grain yield (GY) react to elevated CO2 concentrations were higher under DI than RI, as well as the leaf water use efficiency (WUEL ) and water productivity (WP). The DI900 treatment in which the irrigation amount was reduced by 30% only decreased the TDW and GY by 7 and 5% when compared with RI900. The variation of GY was consistent with the variation of kernels per ear (KPE), but was not directly related to hundred-grain weight (HGW). The above results show that when atmospheric CO2 concentrations rise in the future, deficit irrigation would be an effective way of saving water and would not only have a mitigating effect on water crises, but would also contribute to improving WP, which is more important in terms of actual production.

Publisher URL: www.sciencedirect.com/science

DOI: S0378377417303128

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.