For decades, farmers and scientists have debated a simple but critical question: Is it better to plow fields before planting or to leave the soil undisturbed? Now, an international research team, led by Shi Qibin from the Institute of Geology and Geophysics of the Chinese Academy of Sciences, has found an answer by "listening" to the ground.

The study, published on Friday in the journal Science, shows that common agricultural practices — such as deep plowing and the use of heavy machinery — can severely disrupt the soil's natural sponge-like structure, reducing its ability to help crops withstand both flooding and drought.

Unlike traditional lab-based soil research, scientists from institutes in China, the United States and the United Kingdom used a novel approach. They deployed fiber-optic cables — the same type that powers the internet — as a large-scale sensor array across a 160-meter-wide experimental farm in the UK.

"With the advancement of fiber-optic sensing technology, by sending modulated laser pulses into an optical fiber and analyzing the signals it sends back, we can sense the tiny vibrations in the soil," Shi said. This technique, adapted from seismology, enables the team to create a live, minute-by-minute picture of how water moves through the earth without excavation, he added.

The results indicate that healthy soil possesses a natural internal "plumbing" network of microscopic pores and channels. These structures allow water to soak deep into the ground, where it is stored for plant roots. This reservoir can sustain plants during dry periods.

In contrast, in fields that experience frequent plowing or heavy tractor traffic, this pore network becomes disrupted. Rainfall then accumulates near the surface rather than penetrating deeply. This shallow water also evaporates quickly, leaving deeper soil layers dry and weakening plants' resilience to drought.

To explain their observations, researchers developed a "dynamic capillary stress" model. They challenged the traditional belief that soil strength depends mainly on bulk water content, emphasizing instead the critical role of the pore structure.

In the new model, tiny, capillary-like pores create thin water films. Surface tension in these films acts like tiny rubber bands that reinforce the soil when partially wet. This connected pore network allows deep water penetration. However, when these pores are compressed or destroyed — such as by heavy farm equipment — the altered capillary structure can accelerate water evaporation.

"Rather than a simple collection of particles, soil is a porous medium in which the structure functions like capillary vessels maintaining the water cycle," Shi said.

Based on the findings, Shi highlighted the importance of reconsidering agricultural land management. While plowing may loosen soil and boost short-term harvests, it breaks the invisible mechanical bonds that let soil breathe, circulate water and maintain ecological stability.

"Preserving these natural structures will be critical for helping crops adapt to the increasingly extreme weather conditions brought by climate change," he said.

Shi also noted the low cost of fiber-optic cables, highlighting the potential for large-scale, high-precision farm monitoring.

"By integrating fiber-optic sensing with artificial intelligence, scientists and farmers may soon be able to diagnose the condition of agricultural soils in real time and develop more resilient strategies for sustainable food production, contributing to global food security," he said.