Analysis of biogeochemical processes in plastic-covered soil during establishment period in strawberry cultivation

Abstract

Plastic mulching (PM) has become a widely applied agricultural practice to optimize plant growth. However, it is still under debate how PM influences biogeochemical soil processes and thus important factors of soil quality, such as soil organic matter (SOM) composition, aggregate stability and microbial biomass. Our objective was to identify the impact of PM on biogeochemical soil processes. Therefore, we compared a plastic-covered strawberry cultivation system (PC) with an uncovered system (NC) in three soil layers (0–10, 10–30 and 30–60 cm) at three dates during a 4-month period of strawberry establishment from their transplanting in summer to the beginning of winter. The PC shifted the microclimate of the soil towards higher temperatures but lower moistures in the 0–35 cm soil layer compared to uncovered soil. Predominantly in the surface layer, the PC reduces leaching processes, which can improve nutrient (fertilizer) use efficiency. PC increased SOM and shifted SOM to a more stable SOM. The higher SOM under PC despite larger microbial biomass and elevated temperatures, indicate that belowground biomass inputs compensate the potential SOM losses by an enhanced SOM decomposition under PC. We demonstrated that PC influenced soil processes already within the 4-month period of strawberry establishment, partially down to the 30–60 soil layer. Further, long-term studies are required to estimate the influence of multi-annual PM application on biogeochemical soil processes and on soil quality.