How do rainfall patterns change microbial induced carbon dynamics in soil?

Abstract: Climate change is changing the precipitation patterns around the globe, leading to more extreme weather events like severe drought and heavy rainfalls. These events are intrinsically related to soil moisture fluctuations, which strongly modulates carbon fluxes in terrestrial ecosystems. Studying the behavior of microbial communities present in agriculture soils during drying and rewetting events can help understand soil dynamics under climate change scenarios and help the knowledge gap of how perennial crops can be useful in reducing climate change consequences. In this project, I compared perennial and annual crop systems in depth, down to 90 cm, by characterizing the soils and measuring their microbial responses to a drying and rewetting event. From this study, it was possible to conclude that both soils present a sensitive response to such event, with both lag and recovery times increasing with depth. Moreover, soils exposed to perennial crops generally showed shorter lag and recovery times than those from annual crops, which suggests that perennial crops might have a higher capacity to withstand the negative effects of droughts. Based on the results obtained and the intrinsic limitations of the experiment, it is clear that further investigation is needed, namely in the form of respiration studies, more replicates and statistical analysis.