Farmers could produce more food with the same amount of water by optimising rain use and irrigation, according a new study. The findings could substantially reduce hunger in the face of population growth and buffer some of the harmful effects of climate change on crop yields.
“Smart water use can boost agricultural production – we’ve in fact been surprised to see such sizeable effects at the global level,” says lead-author Jonas Jägermeyr from the Potsdam Institute for Climate Impact Research (PIK).
For their study, the scientists explored a number of very different water management options, from low-tech solutions to the industrial scale. These include water harvesting by collecting excess rain-off in cisterns, mulching (in which soil gets covered with crop residues or huge plastic sheets to reduce evaporation) and upgrading irrigation to drip systems.
Their simulations, which were constrained so that croplands do not expand into forests and no additional water resources are needed, found that the yield increase potential of crop water management is especially high in water-scarce regions such as in China, Australia, the western US, Mexico and South Africa.
In one especially ambitious water management scenario, global kilocalorie production rose by 40 per cent. But even in less ambitious scenarios, integrated crop water management had a significant impact on food production. According to UN estimates, global kilocalorie production needs to rise by 80 per cent to eradicate hunger by 2050.
But putting their findings into practice requires specific local solutions – and this remains a challenge. “A lot of local government regulation and incentives such as-micro credit schemes are needed to put crop water management into large-scale practice,” explains co-author Dieter Gerten.
According to PIK, improved water management will become crucial to reduce food risks caused by the impact of climate change such as increased temperatures, more frequent droughts and changes to rainfall patterns.
“Water management is key for tackling the urgent global sustainability challenge,” explains Johan Rockström, co-author of the study and Director of the Stockholm Resilience Centre. “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.”