Changes in microbial community structure under land consolidation in paddy soils: A case study in eastern China

Abstract

Soil microbial communities are greatly affected by human disturbance and soil physicochemical properties. Land consolidation is an important technology for sustainable agricultural development. However, there are few studies on how land consolidation affects the diversity and structure of soil microbial communities. To understand how land consolidation induced variations in bacterial and fungal communities in soil, we applied a high-throughput sequencing approach of 16S rRNA gene so as to get the information on microbial communities in 20 paddy fields of J County, China. The results showed the huge impact of land consolidation for bacteria as well as fungi, along with the richness and diversity of species critically higher in fields of land consolidation than those not. As for the bacterial communities in fields of land consolidation, the functional diversity of them was also significantly higher, especially nitrogen cycling. The results also showed that the microbial richness and diversity increased in the paddy fields under land consolidation practices of building ditches and applying organic fertilizer compared to others. Interestingly, the relative abundances of heavy-metal tolerant bacteria (Geobacter, Thiobacillus) and fungi (Aspergillus) were increased in the soils from land consolidation areas, which were beneficial microorganisms that could contribute to reduce heavy metal contamination and provide a suitable environment for the growth of plants. Therefore, we concluded that land consolidation could be considered as a viable strategy to improve soil microbial richness and diversity, as well as to increase the abundance of beneficial microorganisms. These findings enhanced our understanding of the importance of land consolidation for increasing the soil microbial diversity and improving soil quality.