Phosphorus and elevated CO₂ enhance drought tolerance

Benefits to crop productivity arising from increasing CO₂ fertilization may be offset by detrimental effects of global climate change, such as an increasing frequency of drought. Phosphorus ( P ) nutrition plays an important role in crop responses to water stress, but how elevated CO2 (eCO₂) and P nutrition interact, especially in legumes, is unclear. This study aimed to elucidate whether P supply improves plant drought tolerance under eCO₂.

Jin et al. use a free-air CO₂ enrichment system to study the effects of phosphorus supply and elevated CO₂ on responses to drought stress of field pea (Pisum sativum) grown in P-deficient vertisol. They find that P application and elevated CO₂ interactively enhance water-use efficiency and improve tolerance to periodic drought as a result of decreased stomatal conductance, deep rooting and greater availability of inorganic P for carbon assimilation in leaves. An adequate supply of P may therefore help crops better withstand drought under future climate scenarios.

This article appears in the special issue Plants and Climate Change.