Plants create a water reserve in the soil

Terra Daily: Experiments performed at the Paul Scherrer Institute (PSI) reveal that a zone of higher water concentration exists around the roots of a plant. It has long been known that roots alter the soil in their immediate vicinity, where other microorganisms live and the chemical composition is altered compared to that further away from the roots.

An international research team has now demonstrated in experiments at the Paul Scherrer Institute that the soil in the vicinity of roots also contains more water - contrary to the earlier belief that there must be less water in this region, as the plant takes up water from the soil. Apparently, however, plants create a small water reserve that helps to tide them over through short periods of drought. These findings could help, in the long term, in the breeding of plants to cope better during periods of drought or in support of the development of efficient irrigation systems.

These results were obtained from experiments carried out with the benefit of neutron tomography at the Paul Scherrer Institute, using a method that makes it possible to exactly show the distribution of water to a fraction of a millimetre, without having to remove a plant from the soil. The researchers have published their results in the prestigious journal New Phytologist.

"The question of how plants take up water is not only relevant to the development of new, water-efficient strains of plants, but also for improving climate models", explains Sascha Oswald, from the Institute of Earth and Environmental Science at the University of Potsdam, "because typically more than half of all the water that falls onto the earth's surface as rain in a humid climate is taken up by plants and then passes back to the atmosphere through the plants."...

Photo of plant roots with striga plant connected, from the USDA Forest Service