Staple crops, including wheat, rice and maize, production of which use 85 per cent of the World’s fresh water resources, account for around half of all water scarcity problems, a new study has found. The study, conducted under the EU PROSUITE project (PROspective SUstaİnability Assessment of TEchnologies), modelled water and land use for the 160 most common crops worldwide. image expired

The results suggest that, collectively, staple crops wheat, rice, cotton, maize and sugar cane account for 49 per cent of water scarcity and 42 per cent of land resource stress caused by worldwide crop production. Overall, rice and wheat in particular had the worst impact on land and water.

This figure is expected to rise, causing ever more strain, as the global area increases in response to rises in population towards 2050.

The researchers used a combination of local and global data to ensure accuracy and said that, in light of their findings, research and adoption of sustainable farming techniques which take account of water management and conservation are a global imperative.

However, their results were not so clear cut. The researchers recorded substantial differences between crops depending on their location. Otherwise said, in areas which are environmentally suited to production, a given crop has much less of an impact; wheat produced in central and northern Europe, where it is largely rain-fed, was found to have minimal impact on water scarcity. This is in contrast to wheat produced in arid regions such as Texas, USA, where wheat production has a much larger impact, for example by putting strain on the non-replenishing Ogollala aquifer, one of the world’s largest underground water sources.

The study also identified crops that are contributing to water shortages, but are of low economic value. Of these, oil crops such as castor and safflower, grown in developing countries, were the worst. Castor and safflower were found to account for 15.8 and 9.8m3 respectively of water per US dollar generated from sale, whereas over 80 per cent of the crops assessed were found to use between 0 and 2 m3 of water per US dollar.

The researchers devised a model which they claim can, by combining local and global assessments, be a useful tool in informing locations for feasible and sustainable agricultural expansion. Nevertheless, the model does have some inherent uncertainties; its developers said failure to account for socio-economic differences, such as the level of wastewater treatment, means it may overestimate scarcity in some instances.