Effects of Wheat-Faba Bean Intercropping on Soil Microbial Community Structure in the Rhizosphere

Abstract

Phospholipid fatty acids (PLFA) analysis and real-time quantitative PCR were used to investigate the effect of wheat-faba bean intercropping on soil microbial community in the rhizosphere and ammonia monooxygenase (amoA) gene abundances of ammonia-oxidizing archaea (AOA) and bacteria (AOB) at harvest stage via field trials in the red soil. We found that the bacteria and fungi of faba bean and actinomycetes of wheat in the rhizosphere showed significant (p < 0.05) difference between intercrops and monocrops at harvest. In total, 37 PLFA were detected at harvest stage in the rhizosphere, including 31 bacterial PLFA, 3 fungal PLFA, and 3 actinomycete PLFA. Compared with the rhizosphere of monocropped faba bean, a lower AOB abundance was found in the intercropping at harvest stage, whereas no significant difference in the AOB abundance was found in the rhizosphere of monocropped and intercropped wheat. There was no significant difference in the AOA abundance between monocrops and intercrops rhizosphere, but a higher AOA abundance in the intercropping systems was found. After intercropping, the abundance of AOB in rhizosphere was significantly higher than that of AOA. Our findings suggest that wheat-faba bean intercropping may change the micro-environment and microbial community structure in the rhizosphere.