• Understanding them is essential for optimizing the efficient use of water resources and strengthening the resilience of crops in the face of climate change

Soil is a living, dynamic system that underpins agricultural production and the sustainability of ecosystems. In this context, understanding how water moves within it is essential for optimising the efficient use of water resources and strengthening the resilience of crops to climate change. However, the processes that regulate this movement are complex and often invisible.

In this regard, the NEIKER technology centre, through the national Bioflow projects and via Daniel Patko’s Ramón y Cajal fellowship, is working on the development of new methodologies to analyse how soil biological activity influences water availability for plants.

To this end, the centre is focusing on the interaction between roots, microorganisms and soil structure, with the aim of generating knowledge that can be applied to more sustainable agriculture.

The complex paths of water beneath our feet

In this scenario, the behaviour of water in the soil largely determines the development of healthy crops. If it moves too easily through the pores, it infiltrates to greater depths before the roots can take it up. Conversely, if infiltration is reduced too much, water is lost through runoff and evaporation. This water stress is also reflected in the root zone: when the soil begins to dry out, restricting water movement can be beneficial, but once it is dry, facilitating the transport of absorbed water helps the plant to make the most of it.

Understanding what regulates the flow of water around plant roots is crucial, but the process is more complex than it seems. The soil surrounding plant roots is constantly being reshaped by living organisms, from earthworms to microbes. More importantly, much of this activity remains hidden from view. Because of the soil’s opacity, studying the organisms that live beneath our feet is a challenge. Many soil organisms are highly sensitive to disturbances, and digging and sampling can alter the very processes being investigated. Furthermore, soil properties can vary considerably over short distances, making it difficult to obtain consistent measurements.

New approaches to a complex problema

NEIKER is developing innovative solutions to tackle these challenges, focusing on how roots and microorganisms alter water pathways in the soil. Microfluidic devices help to analyse biological secretions and visualise the movement of water within the microscopic network of pores. New experiments reveal how microbes alter air-water interfaces – the barriers that prevent water from entering new soil pores. Artificial soils recreate water infiltration under controlled laboratory conditions.

“We have shown that motile microorganisms can reduce the water inflow pressure in soil pores by up to 15 per cent by altering the air-water interfaces. The effect is considerable.” says Lionel Dupuy, an Ikerbasque researcher at NEIKER.

The study is also aided by the use of computer simulations, the results of which show that facilitating water transport generally improves water availability during water stress.

“The research is still at an early stage, but we hope that, in the long term, it will provide a deeper understanding of how soil microbes regulate plant nutrition and help crops adapt to water stress. This could open up new avenues for microbiome-based solutions that improve the resilience of agriculture,” concludes the researcher.

Further Resources

Gomez-Peral, E., Mair, A., Martin-Sanchez, I., de las Heras-Martínez, G., Ptashnyk, M., & Dupuy, L. X. (2026). Root exudation facilitates water infiltration and rewetting of dry soil. Plant, Cell & Environment, 49(2), 728–741.

Mair, A., Gómez-Peral, E., Ptashnyk, M., & Dupuy, L. (2025). Modeling the influence of rhizodeposits on root water uptake. Vadose Zone Journal, 24(6), e70053.

Meza-Manzaneque, B., Gomez-Peral, E., de las Heras-Martinez, G., Martin-Sanchez, I., Stanley-Wall, N., Perez-Estay, B., Lindner, A., Clement, E., Elguezabal, N., & Dupuy, L. X. (2026). How motile bacteria move water in soil. BioRxiv, 2025–2026.