The primary production of plants is limited in most ecosystems by nitrogen and/or phosphorus. The application of nitrogen and phosphorus fertilizers is therefore a general tool to increase plant productivity. However, nutrient additions do not always increase plant productivity, there can be even a decrease in the productivity, or no effect at all. The reasons for these phenomena are currently unknown.
In an article published in Nature Ecology & Evolution scientists represent a hypothesis, based on meta-analysis of published results from fertilization experiments, how the effects of nutrients on plant productivity can be explained by considering the interactions between soil nutrients, soil microbes and plants. Microbes are essential in liberation of nutrients from soil for plant growth but microbes also compete for soil nutrients with plants. The hypothesis developed is based on knowledge that the ratio of nitrogen to phosphorus taken by microbes and plants is different and that the nitrogen to phosphorus ratio in different soils varies. Microbial growth in soil is often limited also by available energy (soil organic carbon). The model explaining the variable effects of nutrients on plant growth was constructed based on this wholeness.
The model increases our understanding on the interactions between soil nutrients, microbes and plants, and opens new possibilities to omit loss of fertilizers and harmful effects on the atmosphere and aquatic ecosystems associated to the use of fertilizers in plant production.
The research was a joint effort by several European universities and research institutes, with the CryoCARB research consortium as a core.
The article ”Plant-microbe interactions determine the response of primary production to nutrient addition” was published in September in Nature Ecology & Evolution (Doi: 10.1038/s41559-018-0662-8).
More info:
Professor, emeritus, Pertti Martikainen, tel. +358 50 357 0545, pertti.martikainen@uef.fi
Research director Christina Biasi, tel +358 40 355 3810, christina.biasi@uef.fi
