KALORET

Characterising the links between the water cycle and the N-P-K cycles in a warmed up world. Lessons from two climate change hotspots

Creaf leader

Nitrogen (N), phosphorus (P) and potassium (K) are key elements for plant growth, and as such, they play a central role in the world's agricultural production. Their extensive use in commercial fertilisers, however, has led to serious environmental concerns, including the acidification of soils, the emission of greenhouse gases, high nitrate concentrations in aquifers and coastal eutrophication.

Concerning K, we are far from understanding what fluxes exist between land and aquatic systems and the role played by human activities in these fluxes. K regulates plant water-use efficiency, so in light of future scenarios of water scarcity, disentangling K inputs and outputs is crucial. In addition, global water resources have been deeply transformed in the past century, and how changes in the hydrological cycle affect the transfer of nutrients from land to the sea remains poorly understood.

Within this context, the overarching goal of KALORET is the accurate characterization of the input and output fluxes of nitrogen, phosphorus and especially potassium (hereafter, N-P-K) using river basins as comprehensive regional functional units. We will study N-P-K fluxes in boreal, temperate and semiarid basins, and evaluate the differences in the latitudinal gradient. With KALORET I will provide for the first time a complete description of land-to-sea K fluxes, which are very little studied but can be critical in water-stressed agricultural systems, and I will quantify N-P-K fluxes in Mediterranean and boreal rivers, two regions of enormous importance in global warming scenarios and with a key role for the global carbon cycle and with regard to hydrological changes. The results of KALORET will serve to address the challenge of how to achieve a more sustainable use of water and N-P-K resources, quantifying stocks and transfers in agricultural and urban systems and minimising harmful surpluses in freshwaters and marine waters.

Proyecto PID2021-128778OA-I00 financiado por MCIN/ AEI /10.13039/501100011033

AEI