Could global water management feed the hungry?

Scientists investigating the potential to produce more food with the same amount of water, by optimising rain use and irrigation, have determined that improved agricultural water management could halve the global food gap by 2050. The yield increase potential was found to be particularly large in water-scarce regions such as Australia.

Finding that the potential has previously been underestimated, the researchers determined that investing in crop water management could substantially reduce hunger while at the same time compensating for population growth. However, putting the findings into practice would require specific local solutions, which remains a challenge.

“Smart water use can boost agricultural production — we’ve in fact been surprised to see such sizeable effects at the global level,” said lead author Jonas Jägermeyr from the Potsdam Institute for Climate Impact Research. In an ambitious water management scenario, global kilocalorie production could rise by 40% (according to UN estimates roughly 80% would be needed to eradicate hunger by the middle of this century). But even in more modest scenarios, the results show integrated crop water management could make a crucial contribution to feeding the poor, said Jägermeyr.

The scientists took into account a number of very different water management options, from low-tech solutions for smallholders to the industrial scale. Water harvesting by collecting excess rain run-off for instance in cisterns — for supplementary irrigation during dry spells — is a common traditional approach in some regions in Africa, but is underused in many other semi-arid regions such as Asia and North America. Mulching is another option — the soil gets covered either simply with crop residues left on the field, reducing evaporation, or with huge plastic sheets. A major contribution to the global potential is upgrading irrigation to drip systems.

Water management becomes increasingly important under ongoing climate change, as global warming is likely to increase droughts and change rainfall patterns, making water availability even more critical than before.

“Water management is key for tackling the greater sustainability challenge,” said Wolfgang Lucht, co-author of the study and co-chair of PIK’s research domain Earth System Analysis. “Since we’re rapidly approaching planetary boundaries, our study should indeed draw the attention of decision-makers of all levels to the potential of integrated crop water management.”