Earthworm is potential to replace synthetic fertilizers

Researchers at Dublin College University (Ireland) have revealed a "new profound insight" into the importance of what occurs underneath the soil's surface, where plants get nutrients.

They discovered a completely undiscovered "shortcut" in the nitrogen cycle in soil, in which active earthworms quickly enrich the soil and plants with the nitrogen released through their mucus. Soil animals provide a beneficial but indirect, sluggish, and cumulative effect in the nutrient cycle.

Prof. Olaf Schmidt of the UCD School of Agriculture and Food Science said, "The really novel insight we discover is that the amount of nitrogen released by earthworms is swiftly absorbed by plants, contrary to what we believe about the microbial cycle. Our research showed that nitrogen (N) and carbon (C) may be rapidly transported from soil animals to plants "'.

The presence of earthworms in soil has been shown to increase plant production in the long term through burrowing and breeding, which contribute to the formation of proper soil structure and the release of nitrogen contained in the soil's organic matter.

Through the use of a stable isotope tracer, a consortium of researchers from Ireland, Germany, and China was able to follow the transition of nutrients from earthworms to the soil, wheat plants, and insects in the laboratory and field.

After just two hours in the laboratory and 24 hours in the field, it was observed that nitrogen generated by earthworms was collected by insects. The researchers were surprised by the speed with which nitrogen moved from earthworm to soil, roots to plants, and insects feeding on plant sap.

"This is interesting because it demonstrates that earthworms may provide nitrogen directly to plants at precisely the time they need it since their activities and those of the plants are coordinated by environmental conditions such as temperature and moisture," Schmidt said.

The newly discovered benefit may be particularly beneficial in agricultural systems trying to lessen their dependence on synthetic fertilizers. As a result, many agricultural sectors should optimize the economic advantages of natural nitrogen provided by earthworms as a possible replacement for synthetic fertilizers, which are now expensive due to supply chain constraints. The globe is still reeling from the outbreak of COVID-19 and excessive energy costs.

Prof. Schmidt said, "This study may give insight into how farmers manage their land, the health of the soil, and the source of nitrogen." By using cultivation techniques that enhance earthworm growth, the advantages of this active nitrogen may be maximized. We knew that earthworm populations contributed agronomically important quantities of nitrogen to the soil from a prior study, but we were unaware that they could also give nitrogen to plants in that dynamic "'.

Farmers, for example, cannot always predict when to use mineral or synthetic fertilizers, since plants may not need nitrogen if the weather is too cold or too dry. And then the costly nitrogen is lost to the environment, either as nitrates seep into groundwater, as nitrogen, or as a gas discharged into the atmosphere.

According to experts, all types of nitrogen naturally derived from soil reserves through decomposition and mineralization have a significant economic and environmental value, so it is necessary to maximize it. 

While earthworms will never be able to completely replace mineral and organic fertilizers, their usage as a natural supply of nutrients may help farmers balance their use and save expenses.

"In short, this is an additional strong reason to improve our knowledge of soil science and promote the usage of soil creatures such as earthworms, since they will improve agricultural productivity in the future, more sustainable and ecologically friendly while being economically viable, "Prof. Schmidt said.