Soil nitrous oxide emissions in a maize (Zea mays L.) crop in response to nitrogen fertilisation
Context. An appropriate use of the fertiliser technology may lead to a more efficient N absorptionand to the reduction of economic and environmental costs. Aims. This study sought to quantify N2Oemissions generated from soil and the residual nitrate (NO3−) up to 2 m depth in field conditions in amaize crop under supplementary irrigation and fertilised with two nitrogen (N) sources (UAN andurea) at increasing N rates (0, 80, 160 and 250 kg N ha−1) in the Semi-arid Argentine Pampas.Methods. Throughout the crop cycle, emissions were monitored daily with static chambersduring the first week after fertilisation; then sampling frequency was gradually reduced until theend of the experiment. Key results. There were no yield responses to the use of differentsources and N rates. Crop N uptake saturated at 80 kg N ha−1, reaching 300–310 kg N ha−1.Residual NO3− increased significantly with the highest rates of N fertiliser. Total N2O emissionsdiffered significantly only among fertiliser rates. The N2O emissions were lower at 80 than at160 and 250 kg N ha−1. Conclusions. The N2O emissions measured were lower than thosecalculated by the IPCC, even when only direct emissions were considered. No grain yield increasewas observed due to N fertilisation, with a non-limiting supply of N-NO3− at the beginning of thecrop cycle and of N from mineralisation. Implications. This excess of N can generate negativeenvironmental effects due to higher emissions of N2O and residual N-NO3− that can be leached.
| Main Authors: | , , , |
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| Format: | info:ar-repo/semantics/artículo biblioteca |
| Language: | eng |
| Published: |
CSIRO Publishing
2022-06-13
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| Subjects: | Impacto Ambiental, Gases de Efecto Invernadero, Riego, Zea Mays, Maiz, Rendimiento de Cultivos, Argentina, Environmental Impact, Greenhouse Gases, Irrigation, Maize, Crop Yield, Urea, Nitrogen Fertilizers, Abonos Nitrogenados, Lixiviación de Nitrato, Nitrate Leaching, Fertilización Nitrogenada, |
| Online Access: | http://hdl.handle.net/20.500.12123/19308 https://www.publish.csiro.au/sr/fulltext/SR21094?subscribe=false https://doi.org/10.1071/SR21094 |
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| Summary: | Context. An appropriate use of the fertiliser technology may lead to a more efficient N absorptionand to the reduction of economic and environmental costs. Aims. This study sought to quantify N2Oemissions generated from soil and the residual nitrate (NO3−) up to 2 m depth in field conditions in amaize crop under supplementary irrigation and fertilised with two nitrogen (N) sources (UAN andurea) at increasing N rates (0, 80, 160 and 250 kg N ha−1) in the Semi-arid Argentine Pampas.Methods. Throughout the crop cycle, emissions were monitored daily with static chambersduring the first week after fertilisation; then sampling frequency was gradually reduced until theend of the experiment. Key results. There were no yield responses to the use of differentsources and N rates. Crop N uptake saturated at 80 kg N ha−1, reaching 300–310 kg N ha−1.Residual NO3− increased significantly with the highest rates of N fertiliser. Total N2O emissionsdiffered significantly only among fertiliser rates. The N2O emissions were lower at 80 than at160 and 250 kg N ha−1. Conclusions. The N2O emissions measured were lower than thosecalculated by the IPCC, even when only direct emissions were considered. No grain yield increasewas observed due to N fertilisation, with a non-limiting supply of N-NO3− at the beginning of thecrop cycle and of N from mineralisation. Implications. This excess of N can generate negativeenvironmental effects due to higher emissions of N2O and residual N-NO3− that can be leached. |
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