Soil microbial composition varies in response to coffee agroecosystem management
Stephanie D. Jurburg, Katherine L. Shek, Krista L. McGuire
Abstract
Soil microbes are essential to the continued productivity of sustainably managed agroecosystems. In shade coffee plantations, the relationship between soil microbial composition, soil nutrient availability and coffee productivity have been demonstrated, but the effects of management on the composition of the soil microbial communities remains relatively unexplored. To further understand how management modulates the soil microbiome, the soil fungal and bacterial communities, soil chemistry, and canopy composition were surveyed in a Nicaraguan coffee cooperative, across 19 individual farms. Amplicon sequencing analyses showed that management (organic or conventional), stand age and previous land use affected the soil microbiome, albeit in different ways. Bacterial communities were most strongly associated with soil chemistry, while fungal communities were more strongly associated with the composition of the canopy and historical land use of the coffee plantation. Notably, both fungal and bacterial richness decreased with stand age. In addition to revealing the first in-depth characterization of the soil microbiome in coffee plantations in Nicaragua, these results highlight how fungal and bacterial communities are simultaneously modulated by long-term land use legacies (i.e. an agricultural plot's previous land use) and short-term press disturbance (i.e. farm age).