The Role of Soil Microbiome in Abating Intra-plant Competition

Abstract

With advancing agricultural practices, studying the role of soil microbiome in plant health and fitness has become more important than ever. Plants compete with each other at both intra and interspecies levels, and roots are the major organ that drives this competition. In this experiment, two types of soil were used to study how the absence of soil microbiomes could influence plant growth and competition. Additionally, a third type of soil, which was native soil with the addition of a sole benign microbe inoculation, was integrated into the experiment to explore how the introduction of beneficial microbiomes could impact plants’ behaviors. We hypothesized that plants deprived of soil microbiomes may act aggressively in an increasing proximity environment and that introducing a beneficial bacteria could have an overall positive impact on plant growth. The findings showed inconsistent results in determining the impact of microbiomes on plant growth and competition. In our first trial, autoclaving the soil decreased plant-plant competition and enhanced plant growth, however, in the second trial, there was no effect of autoclaved soil on plant competition or growth. The findings also showed that the beneficial bacteria did not affect plant competition or growth, except at a specific density where plant growth was lower with the bacteria added to the native soil than with the native soil control. These results suggest that the effects of microbiomes on plant competition and growth are highly variable and further investigation must be conducted to understand the influence that the microbiome exerts in soil.