Plant-soil feedbacks

Published on March 29, 2020   20 min
I am Ciska Veen, a soil ecologist working at the Netherlands Institute of Ecology, Wageningen, the Netherlands. Today I will talk about plant-soil feedbacks and their role in shaping ecological communities and ecosystem processes.
I start with explaining the definition of plant-soil feedback effects. Plants are rooted in the soil and biotic and abiotic conditions in the soil have an important impact on the growth and performance of plants. At the same time, plants are key factors shaping soil properties and processes. This creates a feedback loop where plants and soil continuously interact with each other, referred to in the scientific literature as plant-soil feedback. Plant-soil feedback is therefore defined as changes to soil properties that are caused by plants, which in turn influence the performance of that plant. Scientists are interested in understanding plant-soil feedback, because this is a key process, that explains the composition and functioning of ecological communities and ecosystems.
The understanding that plant-soil feedbacks can have a fundamental impact on ecosystems is not new. This has already been recognized by humans for thousands of years. Humans have been well aware of the importance of plant-soil feedback effects for plant growth and performance since the beginning of agriculture. Crops affect soil properties in a specific way. For example, they may deplete certain nutrients and they often built up specific pathogens around their roots. These effects of crops and soil properties remain in the soil upon harvest. If then the same crop is grown again in the next year, the yields may be lower because of reduced nutrient availability or because the crop is harmed by specific pathogens that are still present in the soil. Therefore, already in early civilizations, such as the Mayans or the Romans, people have managed plant-soil feedback effects in their agriculture ecosystems by implementing crop rotation. This is defined as the practice of growing different crops in succession on the same land to preserve the productive capacity of that soil.