Written by Stefan Geisan
Stefan Geisan is a Postdoctoral researcher at Wageningen University. He works on soil microbial ecology, looking at the distribution and function of soil organisms and how they might affect the plants in your garden.
Here at Candide, we care about the health of our gardens and the plants within them. Indeed, what we mostly care about is that our plants are looking their best. Some of us might also be growing veggies, shifting from ‘looking-good’ to ‘being productive’. Farmers care about this productiveness, and it's what our food supply depends on. In the end, we all want the same: well-performing plants. But how can we achieve that common goal without negatively affecting our environment?
The key lies beneath our feet! Few widely accepted mechanisms exist to improve soils. Fertilisers and water help plants grow, but there are other debated and context-dependent methods to help plants, like pesticides. But in an era of water pollution through overfertilization and insect-decline through pesticide-application, we should consider a better way of providing nutrients and pest-management to our plants.
It's easy to forget that 50% of plants are belowground! Soil is essential for plant performance and, therefore, all human life. It's easy to forget about that though; we tend to care most about what we can see aboveground.
There are many reasons why we should care about the parts of plants below ground. Not only do we commonly eat many of them (including potatoes, carrots and many more) but they are essential for the plant to take up water and nutrients. They also take up some pesticides, which are added to the soil before the plants begin to grow in many agricultural systems.
Roots are essential for plants and therefore all life on Earth
Soils can be incredibly diverse. Abiotic differences like pH are nicely illustrated by plants like Hibiscus that change flower colour depending on the pH. Some soils also naturally contain more nutrients or store more water than others. But the true scale of diversity only becomes apparent when we look at soil organisms.
Hibiscus plants change flower colour depending on soil pH
Plants are not alone in the soil! Millions of bacteria, fungi and other soil creatures interact with plants in loads of different ways.
As gardeners, we are well aware of creatures that eat or kill our plants. These plant pests destroy the beauty of our plants and can cause substantial economic losses. But these evil guys represent only a tiny fraction of all soil life, and many soil organisms are good for plants, providing food and fighting enemies.
Most soil organisms simply hang around without directly affecting plants, but they are equally important for soil health and plant performance. They decompose organic material, making nutrients available for plants.
There is more beneath our feed than plants! Mushrooms only pop-up from a dense underground network of hyphae once a year. All soil organisms are doing something for soils and plants, but we usually don’t see them
Soils and its biodiversity should not be seen merely as a medium, and we should work together with the underground life to help plants reach their maximum potential!
Scientists are only now starting to understand the complexity of soil biodiversity but increasingly appreciate that targeted plant promotion might soon be a reality!
My role as a Dutch/German?
In Germany, where I am from, and in the Netherlands, where I work, we share many things with the UK. Soils, plants and climate are somewhat similar, including the rain.
From a professional view as a soil scientist, I am also tightly connected to the UK. I collaborate on diverse projects with many people from across the country have realised that we can only expand our knowledge if we work together!
I have also recently realised that without recognising plants as the central node that links the above and belowground worlds, my science wouldn’t make much sense. My home-gardening has also made me realise how much we need plants and soils for many reasons. We need to make the best of our soils to ensure not only our success as gardeners but also to ensure the sustainability of life on Earth.
For World Soil Day we are creating a week worth of content to educate and inspire gardeners into loving the soil, tardigrades and the little known facts about soil. We want to empower everyone to take ownership over their own plot of land to help the environment, prevent climate change and to help meet UN Global Goals.