Surprise: plants possess a second root network

Until now, scientists believed that plant roots were primarily concentrated near the surface. However, research published in Nature Communications reveals that 20% of the studied plants possess a second root network extending much deeper into the soil.


These secondary roots, sometimes reaching over 3 feet (1 meter) deep, allow plants to access nutrients otherwise unavailable. This adaptation could be a response to unfavorable surface conditions, such as drought or nutrient deficiency. Plants thus appear capable of 'choosing' to exploit these deep resources when needed.

The study is based on soil samples collected from 44 sites worldwide, covering various ecosystems. Researchers identified a so-called 'bimodal' pattern, where root mass shows two distinct peaks at different depths. This phenomenon, although previously known, had never been documented on such a scale.

The implications of this discovery are vast, particularly regarding carbon storage. Deep soils could play a more significant role than expected in carbon sequestration, offering new avenues to mitigate climate change effects.

This research challenges several assumptions about root growth and their role in ecosystems. It also suggests that plants might be more resilient to environmental changes than we previously thought.

How do plants access deep nutrients?

Plants develop various strategies to access deep nutrients. These mechanisms include growing specialized roots capable of penetrating compacted soil layers.

Nutrients like nitrogen and phosphorus, essential for plant growth, are often more abundant at depth. Secondary roots allow plants to bypass intense surface-level competition for resources.

This adaptation is particularly important in arid or nutrient-poor ecosystems. It illustrates plants' remarkable ability to adapt to their environment for survival and growth.

What's the impact of this discovery on climate change mitigation?

The discovery of deep roots could significantly influence carbon sequestration strategies. Deep soils, less affected by surface disturbances, offer a stable carbon reservoir.

Plants play a key role in the carbon cycle by absorbing atmospheric CO2. Storing this carbon in deep roots could prolong its stay in the soil, reducing its return to the atmosphere.

This perspective opens new pathways for developing crops specifically designed to maximize deep carbon storage.