A researcher team led by Prof. WANG Kelin from the Institute of Subtropical Agriculture of the Chinese Academy of Sciences has revealed how intensive agriculture affects the complexity and stability of soil biota networks, and how these effects are linked to soil functions. Their study was published in Global Change Biology on January 22.

Soil ecosystems comprise intricate networks of organisms that interact through material, energy, and information exchanges, playing a fundamental role in maintaining ecosystem functions. However, agricultural activities such as tilling, weeding, and fertilization can disrupt these delicate interactions. Understanding how soil biota networks respond to agricultural intensification is crucial for developing sustainable farming and land management strategies.

To investigate these effects, the researchers conducted a regional-scale sampling in a karst region of southern China. They selected four types of agricultural land representing different levels of intensification on two primary soil types—calcareous soil and red soil. These included pasture (lowest disturbance), sugarcane farmland, rice paddy fields, and maize cropland (highest disturbance).

The researchers found that as agricultural intensification increased, soil biota networks became more complex but also less stable. Further analysis indicated that a stable soil biota network is more critical for maintaining high soil function than network complexity alone.

Additionally, the researchers highlighted the essential role of soil microfauna, such as nematodes, protozoa, and arthropods, in stabilizing soil communities. Their findings suggest that these organisms exert top-down control, helping to maintain overall soil biome stability. A stable microfauna community was found to support soil functions more effectively than other biological groups.

"Our study represents a considerable advance in linking soil biota network stability to soil ecosystem functions, knowledge of which could be used to enhance agricultural sustainability and crop productivity," said Prof. ZHAO Jie, corresponding author of the study. "These findings also have implications for rational agriculture management."

Selected four agricultural land use types in this study (Image by LONG Xianwen)

Drivers of soil biota network complexity and stability (Image by LONG Xianwen)

The relationship between soil multifunctionality and community stability of organisms (Image by LONG Xianwen)