A Microbiological Approach to Alleviate Soil Replant Syndrome in Peaches

Abstract

Replant syndrome (RS) is a global problem characterized by reduced growth, production life, and yields of tree fruit/nut orchards. RS etiology is unclear, but repeated monoculture plantings are thought to develop a pathogenic soil microbiome. This study aimed to evaluate a biological approach that could reduce RS in peach (Prunus persica) orchards by developing a healthy soil bacteriome. Soil disinfection via autoclave followed by cover cropping and cover crop incorporation was found to distinctly alter the peach soil bacteriome but did not affect the RS etiology of RS-susceptible ‘Lovell’ peach seedlings. In contrast, non-autoclaved soil followed by cover cropping and incorporation altered the soil bacteriome to a lesser degree than autoclaving but induced significant peach growth. Non-autoclaved and autoclaved soil bacteriomes were compared to highlight bacterial taxa promoted by soil disinfection prior to growing peaches. Differential abundance shows a loss of potentially beneficial bacteria due to soil disinfection. The treatment with the highest peach biomass was non-autoclaved soil with a cover crop history of alfalfa, corn, and tomato. Beneficial bacterial species that were cultivated exclusively in the peach rhizosphere of non-autoclaved soils with a cover crop history were Paenibacillus castaneae and Bellilinea caldifistulae. In summary, the non-autoclaved soils show continuous enhancement of beneficial bacteria at each cropping phase, culminating in an enriched rhizosphere which may help alleviate RS in peaches.

Soil Bacteriome Resilience and Reduced Nitrogen Toxicity in Tomato by Controlled Release Nitrogen Fertilizer Compared to Urea

“…Soil sterilization via autoclave may bring strong benefits to plants, particularly in the short term (i.e., within one planting cycle). In a recent study conducted by Newberger et al [29], it was found that plant biomass increased in the first cycle of planting, but in the second cycle, biomass decreased in the soils that were initially autoclaved. Thus, soil sterilization may benefit plant growth and soil microbiome resiliency, especially in the time period of a single planting cycle.…”

“…The soil was then autoclaved using a STERIS autoclave (STERIS, Dublin, Ireland) for three 15 min liquid cycles at 121 • C. Soil was again dried before administering soil into pots. Autoclave sterilization is commonly used in research to reduce soil microbial diversity [27][28][29]. While certain microbial populations attenuate, some taxa can survive and recover rapidly [30].…”