BACKGROUND AND AIMS: Drought limits maize production in many regions of the world, and this is likely to intensify in future. Elevated atmospheric CO2 (eCO2) can mitigate this by reducing stomatal conductance and water loss without reducing yield. The magnitude of this effect depends on the interaction of eCO2 and drought severity, but scarce data collected under severe drought conditions limit predictions of future maize production. METHODS: We compared the severe drought × eCO2 responses of six maize genotypes from semi-arid and sub-humid growing regions. KEY RESULTS: Genotypic differences were apparent in growth, gas exchange, water relations, grain quality, and biomass at maturity, but the response to eCO2 was consistent. Plants under drought and eCO2 had similar biomass and yield to irrigated plants at ambient CO2. Reduced stomatal conductance and water loss preserved soil moisture equivalent to 35 mm of rainfall and allowed sustained photosynthesis at higher rates for a longer period after watering stopped. Under irrigation, eCO2 improved maize growth but not grain yield. CONCLUSIONS: The results suggest that eCO2 may extend the future land area available to rainfed maize cultivation, but cannot circumvent the absence of seasonal rainfall that restricts maize growth. Elevated CO2 will reduce water requirements of irrigated maize when atmospheric conditions drive high evapotranspiration.
BACKGROUND AND AIMS: Drought limits maize production in many regions of the world, and this is likely to intensify in future. Elevated atmospheric CO2 (eCO2) can mitigate this by reducing stomatal conductance and water loss without reducing yield. The magnitude of this effect depends on the interaction of eCO2 and drought severity, but scarce data collected under severe drought conditions limit predictions of future maize production. METHODS: We compared the severe drought × eCO2 responses of six maize genotypes from semi-arid and sub-humid growing regions. KEY RESULTS: Genotypic differences were apparent in growth, gas exchange, water relations, grain quality, and biomass at maturity, but the response to eCO2 was consistent. Plants under drought and eCO2 had similar biomass and yield to irrigated plants at ambient CO2. Reduced stomatal conductance and water loss preserved soil moisture equivalent to 35 mm of rainfall and allowed sustained photosynthesis at higher rates for a longer period after watering stopped. Under irrigation, eCO2 improved maize growth but not grain yield. CONCLUSIONS: The results suggest that eCO2 may extend the future land area available to rainfed maize cultivation, but cannot circumvent the absence of seasonal rainfall that restricts maize growth. Elevated CO2 will reduce water requirements of irrigated maize when atmospheric conditions drive high evapotranspiration.
Authors: Ursula M Ruiz-Vera; Matthew H Siebers; Deepak Jaiswal; Donald R Ort; Carl J Bernacchi Journal: Plant Cell Environ Date: 2018-08-24 Impact factor: 7.228
Authors: Simona Bassu; Nadine Brisson; Jean-Louis Durand; Kenneth Boote; Jon Lizaso; James W Jones; Cynthia Rosenzweig; Alex C Ruane; Myriam Adam; Christian Baron; Bruno Basso; Christian Biernath; Hendrik Boogaard; Sjaak Conijn; Marc Corbeels; Delphine Deryng; Giacomo De Sanctis; Sebastian Gayler; Patricio Grassini; Jerry Hatfield; Steven Hoek; Cesar Izaurralde; Raymond Jongschaap; Armen R Kemanian; K Christian Kersebaum; Soo-Hyung Kim; Naresh S Kumar; David Makowski; Christoph Müller; Claas Nendel; Eckart Priesack; Maria Virginia Pravia; Federico Sau; Iurii Shcherbak; Fulu Tao; Edmar Teixeira; Dennis Timlin; Katharina Waha Journal: Glob Chang Biol Date: 2014-04-26 Impact factor: 10.863
Authors: Andrew D B Leakey; Elizabeth A Ainsworth; Carl J Bernacchi; Alistair Rogers; Stephen P Long; Donald R Ort Journal: J Exp Bot Date: 2009-04-28 Impact factor: 6.992