Long-term intercropping regulates the community structure of arbuscular mycorrhizal fungi and improves wheat yield

Context

Long-term continuous monoculture has led to frequent cropping obstacles that significantly restrict wheat production. Intercropping of wheat and faba bean is considered an effective strategy to mitigate these challenges, whereas the long-term effects of intercropping on wheat yield remain unexplored.

Objective

This study aimed to assess the impact of long-term intercropping on wheat rhizosphere soil physicochemical properties, arbuscular mycorrhizal fungi (AMF) community composition, and root nitrogen transporter gene expression, with elucidating the synergistic mechanisms underlying yield enhancement.

Methods

A field experiment was conducted to compare two planting modes, wheat monocropping (M) and wheat-faba bean intercropping (I), over two durations (2 and 10 years) to examine their effects on wheat yield, soil physicochemical properties, AMF communities, and root nitrogen transporter gene expression.

Results

Intercropping increased wheat yield compared to monocropping, with the highest yield observed after 10 years of intercropping. Long-term intercropping improved wheat rhizosphere soil structure, significantly increased nutrient content, and enhanced soil fertility. It also increased AMF colonization ability, richness, and diversity, while regulating the AMF community structure, which promoted the expression of nitrogen transporter genes in wheat roots, improving nitrogen absorption, and ultimately boosting yield. These beneficial effects were more pronounced after long-term intercropping.

Conclusion

Long-term wheat-faba bean intercropping enhanced the AMF community composition, improved the soil physicochemical properties, enhanced the nitrogen transport efficiency, promoted wheat growth, and ultimately increased production.

Implications

Long-term intercropping contributes to promoting sustainable agricultural production.