|Title (Primary)||The legacy effect of synthetic N fertiliser|
|Author||Vonk, W.J.; Hijbeek, R.; Glendining, M.J.; Powlson, D.S.; Bhogal, A.; Merbach, I.; Silva, J.V.; Poffenbarger, H.J.; Dhillon, J.; Sieling, K.; ten Berge, H.F.M.|
|Journal||European Journal of Soil Science|
|Topic||T5 Future Landscapes|
|Keywords||15N; Cereal production; Fertiliser requirement; Long-term experiment; Nitrogen recovery; Nitrogen Use Efficiency; Soil N retention; Soil N supply; Synthetic fertiliser N|
Cumulative crop recovery of synthetic fertiliser nitrogen (N) over several cropping seasons (legacy effect) generally receives limited attention. The increment in crop N uptake after the first-season uptake from fertiliser can be expressed as a fraction (∆RE) of annual N application rate. This study aims to quantify ∆RE using data from nine long-term experiments (LTEs). As such, ∆RE is the difference between first season (RE1st) and long-term (RELT) recovery of synthetic fertiliser N.
In this study, RE1st was assessed either by the 15N isotope method, or by a zero-N subplot freshly superimposed on a long-term fertilised LTE treatment plot. RELT was calculated by comparing N uptake in the total aboveground crop biomass between a long-term fertilised and long-term control (zero-N) treatment. Using a mixed linear effect model, the effects of climate, crop type, experiment duration, average N rate, and soil clay content on ∆RE were evaluated.
Because the experimental setup required for calculation of ∆RE is relatively rare, only nine suitable LTEs were found. Across these nine LTEs in Europe and North America, mean ∆RE was 24.4% (±12.0%, 95% CI) of annual N application, with higher values for winter wheat than for maize. This result shows that fertiliser-N retained in the soil and stubble may contribute substantially to crop N uptake in subsequent years. Our results suggest that an initial recovery of 43.8% (±11%, 95% CI) of N application may increase to around 66.0% (±15%, 95% CI) on average over time. Furthermore, we found that ∆RE was not clearly related to long-term changes in topsoil total N stock. Our findings show that the - often used - first year recovery of synthetic fertiliser N application does not express the full effect of fertiliser application on crop nutrition. The fertiliser contribution to soil N supply should be accounted for when exploring future scenarios on N cycling, including crop N requirements and N balance schemes.
|Persistent UFZ Identifier||https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=26013|
|Vonk, W.J., Hijbeek, R., Glendining, M.J., Powlson, D.S., Bhogal, A., Merbach, I., Silva, J.V., Poffenbarger, H.J., Dhillon, J., Sieling, K., ten Berge, H.F.M. (2022):
The legacy effect of synthetic N fertiliser
Eur. J. Soil Sci. 73 (3), e13238