Management Impacts to Soil Microbial Communities in Maine Potato Production

Potato crop management can have substantial impacts on soil health, particularly through practices such as intensive tillage and short crop rotations. This study investigated the impacts of different management practices on soil microbial communities, including rotation length, non-grain rotation crops, green manures, compost amendments, and a soil fumigant using two potato varieties, ‘Caribou Russet’ and ‘Russet Burbank’. Bacterial and fungal communities were characterized from soil samples using amplicon sequence variants (ASVs) of the 16S rRNA and internal transcribed spacer rDNA regions, respectively. Initially, no significant differences were detected between microbial communities; however, after 4 years, significant differences were found. Overall, fungi demonstrated greater sensitivity to management practices than bacteria, with fumigation and compost amendment having the largest impacts on microbial communities. Fumigation resulted in a decrease in the abundance of certain fungal groups, particularly saprotrophs or unidentified fungi. Alternatively, the two largest groups of fungi more abundant in fumigated soils were saprotrophs or plant pathogens. Compost amendment led to substantial increases in fungal diversity, with over 3.5 times more differentially abundant fungal ASVs identified compared with soils without compost. Within these more abundant fungal ASVs in compost-amended soils, plant pathogens made up only 4%, whereas in soils without compost, plant pathogens made up 25% of the most abundant ASVs. In general, compost appeared to positively impact soil microbial communities, and fumigation appeared to negatively impact them. The results of this study could aid farmers in crop management decisions that improve soil health, reduce disease, and increase yields. [Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .