Abstract
Highbush blueberry (Vaccinium corymbosum L.) fields can remain productive for decades. However, some older fields decline in plant health and exhibit lower yields. After re-planting with new stock, the yields continue to suffer. This condition is termed 'Replant Disease'. The causative agent(s) in replant disease in New Jersey blueberry fields are unknown. To assess if low- and high-yield blueberry farm soils from two separate farms contained different microbiomes, we coupled long-read bacterial and eukaryotic ribosomal rRNA operon sequencing using the Oxford Nanopore MinION with stable isotope probing (SIP) to detect (13)C/(15)N-utilising soil microbial communities. The results indicate multiple Bacillus species were active on (13)C/(15)N-growth media (predominantly amino acids and glucose) in low-productivity soils from both farms, while high-productivity and adjacent forest soils contained active Burkholderia and Paraburkholderia species. Eukaryotic community profiling indicated Candida blankii, Nadsonia starkeyi and Sugiyamaella chiloensis were slightly enriched and active in low-productivity soils compared with high-productivity soils. This approach differentiates low- and high-productivity blueberry farm soils by ribosomal RNA operon profiling and SIP. The findings also suggest a diagnostic test of blueberry replant affected soils is feasible and may ultimately be used to improve productivity and potentially detect the responsible pathogenic agent(s) or other deleterious microbes.