Irrigation Scheduling with Soil Gas Diffusivity as a Decision Tool to Mitigate N<sub>2</sub>O Emissions from a Urine-Affected Pasture
Pastures require year-round access to water and in some locations rely on irrigation during dry periods. Currently, there is a dearth of knowledge about the potential for using irrigation to mitigate N<sub>2</sub>O emissions. This study aimed to mitigate N<sub>2</sub>O losses...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-05-01
|
| Series: | Agriculture |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2077-0472/11/5/443 |
| _version_ | 1797534217296412672 |
|---|---|
| author | Camille Rousset Timothy J. Clough Peter R. Grace David W. Rowlings Clemens Scheer |
| author_facet | Camille Rousset Timothy J. Clough Peter R. Grace David W. Rowlings Clemens Scheer |
| author_sort | Camille Rousset |
| collection | DOAJ |
| description | Pastures require year-round access to water and in some locations rely on irrigation during dry periods. Currently, there is a dearth of knowledge about the potential for using irrigation to mitigate N<sub>2</sub>O emissions. This study aimed to mitigate N<sub>2</sub>O losses from intensely managed pastures by adjusting irrigation frequency using soil gas diffusivity (<i>D<sub>p</sub>/D<sub>o</sub></i>) thresholds. Two irrigation regimes were compared; a standard irrigation treatment based on farmer practice (15 mm applied every 3 days) versus an optimised irrigation treatment where irrigation was applied when soil <i>D<sub>p</sub>/D<sub>o</sub></i> was ≈0.033 (equivalent to 50% of plant available water). Cow urine was applied at a rate of 700 kg N ha<sup>−1</sup> to simulate a ruminant urine deposition event. In addition to N<sub>2</sub>O fluxes, soil moisture content was monitored hourly, <i>D<sub>p</sub>/D<sub>o</sub></i> was modelled, and pasture dry matter production was measured. Standard irrigation practices resulted in higher (<i>p</i> = 0.09) cumulative N<sub>2</sub>O emissions than the optimised irrigation treatment. Pasture growth rates under treatments did not differ. Denitrification during re-wetting events (irrigation and rain) contributed to soil N<sub>2</sub>O emissions. These results warrant further modelling of irrigation management as a mitigation option for N<sub>2</sub>O emissions from pasture soils, based on <i>D<sub>p</sub>/D<sub>o</sub></i> thresholds, rainfall, plant water demands and evapotranspiration. |
| first_indexed | 2024-03-10T11:26:31Z |
| format | Article |
| id | doaj.art-14f71b96daec443893b00c3f8e767cc2 |
| institution | Directory Open Access Journal |
| issn | 2077-0472 |
| language | English |
| last_indexed | 2024-03-10T11:26:31Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Agriculture |
| spelling | doaj.art-14f71b96daec443893b00c3f8e767cc22023-11-21T19:32:59ZengMDPI AGAgriculture2077-04722021-05-0111544310.3390/agriculture11050443Irrigation Scheduling with Soil Gas Diffusivity as a Decision Tool to Mitigate N<sub>2</sub>O Emissions from a Urine-Affected PastureCamille Rousset0Timothy J. Clough1Peter R. Grace2David W. Rowlings3Clemens Scheer4Department of Soil and Physical Sciences, Lincoln University, P.O. Box 85084, Lincoln 7647, New ZealandDepartment of Soil and Physical Sciences, Lincoln University, P.O. Box 85084, Lincoln 7647, New ZealandInstitute for Future Environment, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, AustraliaInstitute for Future Environment, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, AustraliaInstitute for Future Environment, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, AustraliaPastures require year-round access to water and in some locations rely on irrigation during dry periods. Currently, there is a dearth of knowledge about the potential for using irrigation to mitigate N<sub>2</sub>O emissions. This study aimed to mitigate N<sub>2</sub>O losses from intensely managed pastures by adjusting irrigation frequency using soil gas diffusivity (<i>D<sub>p</sub>/D<sub>o</sub></i>) thresholds. Two irrigation regimes were compared; a standard irrigation treatment based on farmer practice (15 mm applied every 3 days) versus an optimised irrigation treatment where irrigation was applied when soil <i>D<sub>p</sub>/D<sub>o</sub></i> was ≈0.033 (equivalent to 50% of plant available water). Cow urine was applied at a rate of 700 kg N ha<sup>−1</sup> to simulate a ruminant urine deposition event. In addition to N<sub>2</sub>O fluxes, soil moisture content was monitored hourly, <i>D<sub>p</sub>/D<sub>o</sub></i> was modelled, and pasture dry matter production was measured. Standard irrigation practices resulted in higher (<i>p</i> = 0.09) cumulative N<sub>2</sub>O emissions than the optimised irrigation treatment. Pasture growth rates under treatments did not differ. Denitrification during re-wetting events (irrigation and rain) contributed to soil N<sub>2</sub>O emissions. These results warrant further modelling of irrigation management as a mitigation option for N<sub>2</sub>O emissions from pasture soils, based on <i>D<sub>p</sub>/D<sub>o</sub></i> thresholds, rainfall, plant water demands and evapotranspiration.https://www.mdpi.com/2077-0472/11/5/443N<sub>2</sub>O emissionsautomatic chambersoptimised irrigationmodelled <i>D<sub>p</sub>/D<sub>o</sub></i>pasture management |
| spellingShingle | Camille Rousset Timothy J. Clough Peter R. Grace David W. Rowlings Clemens Scheer Irrigation Scheduling with Soil Gas Diffusivity as a Decision Tool to Mitigate N<sub>2</sub>O Emissions from a Urine-Affected Pasture Agriculture N<sub>2</sub>O emissions automatic chambers optimised irrigation modelled <i>D<sub>p</sub>/D<sub>o</sub></i> pasture management |
| title | Irrigation Scheduling with Soil Gas Diffusivity as a Decision Tool to Mitigate N<sub>2</sub>O Emissions from a Urine-Affected Pasture |
| title_full | Irrigation Scheduling with Soil Gas Diffusivity as a Decision Tool to Mitigate N<sub>2</sub>O Emissions from a Urine-Affected Pasture |
| title_fullStr | Irrigation Scheduling with Soil Gas Diffusivity as a Decision Tool to Mitigate N<sub>2</sub>O Emissions from a Urine-Affected Pasture |
| title_full_unstemmed | Irrigation Scheduling with Soil Gas Diffusivity as a Decision Tool to Mitigate N<sub>2</sub>O Emissions from a Urine-Affected Pasture |
| title_short | Irrigation Scheduling with Soil Gas Diffusivity as a Decision Tool to Mitigate N<sub>2</sub>O Emissions from a Urine-Affected Pasture |
| title_sort | irrigation scheduling with soil gas diffusivity as a decision tool to mitigate n sub 2 sub o emissions from a urine affected pasture |
| topic | N<sub>2</sub>O emissions automatic chambers optimised irrigation modelled <i>D<sub>p</sub>/D<sub>o</sub></i> pasture management |
| url | https://www.mdpi.com/2077-0472/11/5/443 |
| work_keys_str_mv | AT camillerousset irrigationschedulingwithsoilgasdiffusivityasadecisiontooltomitigatensub2suboemissionsfromaurineaffectedpasture AT timothyjclough irrigationschedulingwithsoilgasdiffusivityasadecisiontooltomitigatensub2suboemissionsfromaurineaffectedpasture AT peterrgrace irrigationschedulingwithsoilgasdiffusivityasadecisiontooltomitigatensub2suboemissionsfromaurineaffectedpasture AT davidwrowlings irrigationschedulingwithsoilgasdiffusivityasadecisiontooltomitigatensub2suboemissionsfromaurineaffectedpasture AT clemensscheer irrigationschedulingwithsoilgasdiffusivityasadecisiontooltomitigatensub2suboemissionsfromaurineaffectedpasture |