Are catchment-scale nitrogen and phosphorous use efficiencies controlled by climate?

Background

 

  • Large amounts of nutrients are lost from agricultural fields with negative consequences for the environment

  • Hydrological controls can explain variations in nutrient use efficiency, because water mediates both the uptake by plants and leaching

Here I estimate nitrogen and phosphorous use efficiencies at annual and catchment scale, and compare them to the evaporative ratio.

To hear about this research, see a 2-minute video of my research!

Nitrogen use efficiency

  • NUE increases with ET/P (via increased water and N retention)

  • NUE increases through time

  • Only climatic changes increasing ET/P without negatively affecting yields will improve NUE

With climate change: temperatures and lower precipitation (i.e. increasing evaporative ratios) will potentially lead to increased nutrient retention and therefore decreased nutrient leaching from agricultural fields.

Our results show that changes in climate that include increased evaporation and decreased precipitation can lead to increase N use efficiencies without decreasing yields.

References

 Scaini et al., 2020. Hydro-climatic controls explain variations in catchment-scale nitrogen use efficiency. ERL

 Swaney et al., 2019. Phosphorus use efficiency and crop production: Patterns of regional variation in the United States, 1987–2012. STE

 Lasalletta et al., 2014. 50 year trends in nitrogen use efficiency of world cropping systems: the relationship between yield and nitrogen input to cropland. ERL.

[Watering by Manthana Chaiwong, farm animal by Laymik, fertilizer by Ayumi Aya - the Noun Project]