Quantifying the nitrogen cycle: from farm gate to catchments, groundwater and atmosphere
- Integrated assessment of N-cycle (waterways, groundwater and atmosphere) off-farm contributions in three key catchments to the Cotton industry.
- Surface water quality assessment of major waterways in three cotton growing catchments: Murrumbidgee, Namoi and Nogoa Rivers.
- Bi-monthly longitudinal study of nutrients, major ion and N isotopic contributions from selected sites of the three catchments studied.
- Capture of a major high flow event in selected catchments to compare with dynamics observed during average or low flow conditions.
- Sampling of shallow groundwater in cotton growing regions to assess potential transfers of nutrients to groundwater and potential denitrification pathways (all catchments). Specifically, in the Lower Murrumbidgee, extend the assessment to deeper aquifers.
- Hydrochemical and isotopic characterisation of selected artificial end-members (i.e. fertilisers) to compare to signatures identified in the studied catchments.
- Measurements of site-specific N2O concentrations and site specific N2O Isotopes (δ15Nα, δ15Nβ, δ18O) for assessing district scale nitrous oxide emissions in the studied regions.