Dry roots shrink

Contact with the surrounding soil is lost

Roots of the white lupine in the model. With the help of X-ray computed tomography, UFZ researchers demonstrated that the roots shrink in the event of dryness and form air gaps between the roots and soil. © Ulrich Weller / UFZ
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Plant roots can shrink due to dryness, losing contact with the surrounding soil. Although this effect has been suspected for a long time, it could only be proven with the help of X-ray computed tomography.

The formation of an air gap could initially help the plants to prevent imminent water losses when the soil dries out, write the scientists of the Helmholtz Center for Environmental Research (UFZ) in the journal "Vadose Zone Journal".

Air gaps in drought

For their study, the researchers examined roots of the white lupine in a sandy soil and examined the changes at the soil-root interface during dehydration and irrigation for a month by X-ray computed tomography.

According to the scientists, air gaps, which were caused by the shrinkage of the roots during drought, showed up. "These interactions between the soil structure and the biological activities make the interface between soil and roots a complex, dynamic biomaterial whose importance is only slowly becoming understood, " explains Andrea Carminati from the UFZ.

Plant roots can shrink due to dryness, losing contact with the surrounding soil. Although this effect has been suspected for a long time, it could only be proven with the help of X-ray computed tomography. © Ulrich Weller / UFZ

Permanent damage or short malfunction?

After irrigation, the roots swelled again in the experiment and partially closed the air gaps again. However, the contact was not fully restored in the older part of the taproots. So can severe drought permanently damage the contact of the roots with the soil and thus hinder the water and nutrient uptake of the plants? Or can the plants restore contact? display

Questions that are of great significance for agriculture against the background of climate change and the drier summers expected in northeastern Germany. Therefore, the UFZ soil researchers want to further investigate the interactions of plant roots with X-ray equipment.

(idw - Helmholtz Center for Environmental Research - UFZ, 27.11.2009 - DLO)