Differential responses of the soil microbial community in two pitaya orchards with different mulch types.

To prevent plants from being damaged due to extreme temperature and sunlight, the pitaya orchards in Hainan Province, China, are increasingly adopting living and black fabric cloth mulching. In this study, an Illumina Hiseq sequencer was employed to compare the soil microbial communities of two pitaya orchards, one covered by living mulching (LM) and the other covered by black fabric cloth (FC). Bacterial abundance was higher in the LM orchard than in the FC orchard (1.19 × 10 versus 4.49 × 10 g soil). In contrast, fungal abundance was higher in the FC orchard than in the LM orchard (2.71 × 10 versus 2.97 × 10 g soil). We also found that the most dominant species in the FC orchard were from the genus Neoscytalidium, which included species that could cause infection in a large variety of plant hosts. However, the LM orchard mainly harbored useful fungal species, such as Trichoderma and Chaetomium. Soil nutrients were positively correlated in the FC orchard, which potentially indicated that the FC orchard could demonstrate better fertilizer utilization efficiency. However, the LM and FC strategies have both advantages and disadvantages with regards to the cultivation management of pitaya orchards.