SSRP Abstract

Board 33: Does a Drought Legacy Effect Triticum aestivum Growth?

Student Scientist: Lisa Leonard ’23
Research Mentor: Moriah Young (W.K. Kellogg Biological Station LTER)

Drought is a very common environmental stressor, with a significant increase in severity and frequency of drought events, it is important to understand how this may affect plants but also soil microbes. In this study, we wanted to understand whether or not a past years drought would affect this years plant growth with Triticum aestivum, common wheat.

Drought is a major abiotic stressor to not only plants, but soil microbes. Plants and soil are inherently interconnected and the relationship between them can determine the health of both the plant as well as the soil. In this study, we looked at the effects of a previous years’ drought on the growth of Triticum aestivum, common wheat. Using the Rainfall Exclusion eXperiment (REX) in the LTER at W.K. Kellogg Biological Station, we measured height, greenness, and biomass on wheat. These measurements were conducted in the no till treatments (T2s) and in the drought legacy, irrigated control, and drought footprints with the fungicide and control subplots. A SPAD was used to measure greenness, a proxy for chlorophyll content in leaves. Wheat was harvested in the treatment area, dried, and then weighed for biomass. We expected that drought legacy plots and fungicide subplots would have shorter heights, lower greenness, and less biomass. We found no significant differences between greenness and biomass between each treatment. However, there was a difference in height between the irrigated control and drought legacy fungicide suplots, with the irrigated control plots having lower average heights. This is the opposite of what we expected from our hypothesis. Because the 6-week drought had not started yet, we would not expect an effect from the drought in those footprints. Further, soil microbes could potentially be resilient, resistant, or functionally redundant in their response to the previous years’ drought which could be why we did not see any drought legacy effects on wheat greenness or biomass. Soil samples are being collected to compare the fungal and bacterial communities within these same plots in order to explain their responses to the treatments. It is crucial to understand these plant-soil feedbacks as climate change increases and how plants and soil microbes adapt to the changes within the environment.