Analysis of Changes in Herbaceous Peony Growth and Soil Microbial Diversity in Different Growing and Replanting Years Based on High-Throughput Sequencing

Abstract

The herbaceous peony (Paeonia lactiflora Pall.), a perennial herbaceous flower, can grows continuously for approximately 10 years. However, a replanting problem can occur during division propagation which reduces the land use rate and restricts the development of the herbaceous peony industry. We investigated microbial community changes and soil chemical properties in herbaceous peony soils during different growing and replanting years. The results indicated that the flowering rate, plant height, stem diameter, and leaf area of replanted herbaceous peony were lower, and decreased gradually with increasing replanting years. Compared with the soil after replanting herbaceous peony for one year, soil pH, nutrient contents (AN, AP, AK, and OM), enzyme activities (Inv, Ure, Pho, and Cat), diversity and richness of fungal and bacterial communities decreased after replanting for five years. Long-term replanting increased the relative abundance of harmful soil microorganisms (e.g., Gibberella), and reduced that of beneficial microorganisms (e.g., Bacillus). Overall, after the long-term replanting of herbaceous peony, the soil environment deteriorated, and the soil microbial community structure changed, resulting in the imbalance of soil microecology, damaging the normal growth of herbaceous peony.