Boron application increases growth of Brazilian Cerrado grasses

Nutrients are known to limit productivity of plant communities around the world. In the Brazilian Cerrado, indirect evidences point to phosphorus as the main limiting nutrient, but some fertilization experiments suggest that one or more micronutrients might play this role. Boron is one of the essential micronutrients for plants. Agronomically, it received some attention, but it has mostly been neglected in ecological studies assessing the effects of nutrients on plant growth. Through field fertilization and mesocosm experiments, we show that boron addition increased biomass production of Cerrado herbaceous vegetation. This could be related to a lower aluminium uptake in the boron fertilized plants. Even considering that plant growth was promoted by boron addition due to aluminium toxicity alleviation, this is the first study reporting boron limitation in natural, non-cultivated plant communities, and also the first report of this kind in vegetative grasses. These results contribute to disentangling patterns of nutrient limitation among plant species of the species-rich, aluminium-rich and nutrient-poor Cerrado biome, and highlight the potential role of micronutrients, such as boron, for growth of non-crop plants. Understanding how nutrient limitation differs amongst functional groups in the highly biodiverse areas founded on ancient tropical soils may help managing these plant communities in a changing world.