Interaction between soil and fertiliser nitrogen drives plant nitrogen uptake and nitrous oxide (N2O) emissions in tropical sugarcane systems

• Published in: Plant and soil Vol. 477; no. 1-2; pp. 647 - 663
• Main Authors: Takeda, Naoya, Friedl, Johannes, Kirkby, Robert, Rowlings, David, De Rosa, Daniele, Scheer, Clemens, Grace, Peter
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-08-2022; Springer; Springer Nature B.V
• Subjects: Agriculture; Analysis; Biomedical and Life Sciences; Crop production; Ecology; Emissions; Environmental impact; Fertilizers; Greenhouse gases; Growth; Life Sciences; Nitrogen; Nitrogen fertilizers; Nitrogen isotopes; Nitrous oxide; Plant Physiology; Plant Sciences; Productivity; Research Article; Soil fertility; Soil management; Soil Science & Conservation; Soils; Sugarcane; Temporal resolution; Australia; Germany; Added N interaction; Priming effect; Fertiliser; Emission factor; O priming; N recovery; N; NUE
• DOI: 10.1007/s11104-022-05458-6
• EISSN: 1573-5036
• ISSN: 0032-079X

Aims
High nitrogen (N) fertiliser inputs in intensive sugarcane systems drive productivity but also significant emissions of nitrous oxide (N
2
O), a potent greenhouse gas. Fertiliser and soil N availability for both plant N uptake and N
2
O emissions across different N rates remain unknown, hindering efficient N management. This study investigated the contribution of fertiliser and soil N and their interaction to plant N uptake and N
2
O emissions in two intensively managed tropical sugarcane systems.
Methods
High temporal resolution N
2
O measurements were combined with
15
N recoveries across four N fertiliser rates, (100, 150, 200 and 250 kg N ha
− 1
) in soil, plant and N
2
O emissions.
Results
Cumulative N
2
O emissions ranged from 0.3 to 4.1 kg N ha
− 1
, corresponding to emission factors ranging from 0.7 to 2.4%. Native soil N accounted for > 60% of cumulative N
2
O emissions and total plant N uptake. Fertiliser N addition increased N
2
O emissions from native soil N compared to the unfertilised control, highlighting the interaction between fertiliser and soil N, which determined the overall magnitude but also the response of total N
2
O emissions to N rates dependent on the site conditions. Overall fertiliser
15
N loss responded exponentially to N rates with 50% of applied N fertiliser permanently lost even at the recommended N rate.
Conclusions
The interaction between fertiliser and soil N and its contribution to N uptake and N
2
O emissions demonstrate the importance of integrating soil fertility management with N fertiliser rate recommendations for sugarcane systems to maintain crop productivity and reduce environmental impacts.