Janna Barel gave a pitch about her research at the opening of the WUR academic year themed about “Food and Agriculture: Europe and the World”.
She delighted the audience bringing with herself “the soil black box” and disclosing some of the secrets that are hidden in it and that are key for a sustainable agriculture and a healthy food production.
“How would the testament of a plant look like, and how would it influence the growth of next plants? Soil life provides many soil functions, including nutrient cycling, carbon sequestration and crop productivity. A handful of soil contains 100 000-1000 000 species of bacteria. Most of soil life is invisible to the eye. Nevertheless, the very small are responsible for the legacy effects that plants can have on next plant productivity.
Technically, a plant’s legacy includes physical, chemical and biological changes in soil conditions, induced by plant growth. Plant roots growing in the soil encounter micro-organisms including pathogens, antagonists that help protect the plants from disease, and mutualists such as mycorrhizal fungi that help the plant take up nutrients in exchange for sugars. The microbial community is partially shaped by plants, and remain in the soil after that plant dies or is harvested. Also, growing plants take-up nutrients, such as nitrogen, which can leach-out from agricultural soils to surface waters. Thus by growing plants, such as cover crops, on agricultural soils helps maintain clean water. The nutrients which are allocated into plant biomass can be recycled again by decomposition. Decomposition is performed by soil organisms and is the principle process by which nutrients are made available to next plants and carbon can be sequestered in soil.
A plant’s legacy is part of nature’s circular economy, with soil organisms being the engine of that economy. Plant-soil interactions are intricate and complex. Understanding the relationships between plants and soil organisms is essential for managing soil functioning. We can study plant-soil interactions by conducting field, greenhouse and lab experiments, and combining classic techniques and novel tools such as DNA-sequencing, tea-bag index, and remote sensing to study soil legacies of plants. By studying plant-soil interactions in agricultural systems alongside natural systems we will be able to discover the differences and similarities. By learning from nature we can suggest sustainable management practices of agriculture.
What can we do to support nature’s circular economy? We can start with a simple thing to support soils complexity. We can start by returning a part of the biomass produced on the soil. By leaving the autumn leaves in your garden, by leaving crop residues on the fields we can fuel soil life. Because when we feed the soil, the soil will feed us. “
Janna M. Barel
Please click the link below to view the presentation, it might take a few seconds before it starts: