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April 05, 2024
Oliver Weber
Quantifying Excess Nitrogen Loads in Fresh Water
December 2020
At least 43% of New Zealand’s agricultural land (31% of New Zealand’s total land area) is in catchments that are under pressure (‘pressure’ meaning the ratio of the current load of total nitrogen to the maximum allowable load of nitrogen that can be emitted and still meet current regulatory criteria). The nitrogen load reductions required to meet water quality objectives in some regions are large relative to existing loads. The current load is twice the maximum allowable load in parts of the Waikato, Manawatu-Wanganui, Marlborough, Canterbury, Otago and Southland.
Research Findings Brief prepared by Our Land and Water
4928 KB | Adobe Acrobat PDF File
Source: Nitrogen loads to New Zealand aquatic receiving environments: comparison with regulatory criteria, Ton H. Snelder, Amy L. Whitehead, Caroline Fraser, Scott T. Larned & Marc Schallenberg (New Zealand Journal of Marine and Freshwater Research, July 2020)
doi.org/10.1080/00288330.2020.1758168
Implications of water quality policy on land use: A case study of the approach in New Zealand by R. W. McDowell, P. Pletnyakov, A. Lim and G. Salmon. Marine and Freshwater Research, October 2020. doi.org/10.1071/MF20201
Quantifying contaminant losses to water from pastoral land uses in New Zealand III. What could be achieved by 2035? McDowell, R. W., Monaghan, R.M., Smith, C., Manderson, A., Basher, L., Burger, D.F., Laurenson, S., Pletnyakov, P., Spiekermann, R., Depree,
C. (New Zealand Journal of Agricultural Research, 2021). doi.org/10.1080/00288233.2020.1844763
Essential freshwater: Impact of existing periphyton and proposed dissolved inorganic nitrogen bottom lines Ministry for the Environment with assistance from the LUS research team (Publication reference number ME 1467, September 2019) www.mfe.govt.nz/publications/fresh-water/essential-freshwater-impact-of-existing-periphytonand-proposed-dissolved
The land use suitability concept: Introduction and an application of the concept to inform sustainable productivity within environmental constraints R.W. McDowell, T. Snelder, S. Harric, L. Lilburne, S.T. Larned, M. Scarsbrook, A. Curtis, B. Holgate, J. Phillips, K. Taylor (Ecological Indicators, August 2018). doi.org/10.1016/j.ecolind.2018.03.067
Anthropogenic increases of catchment nitrogen and phosphorus loads in New Zealand Snelder T, Larned S, McDowell R (New Zealand Journal of Marine and Freshwater Research, October 2017) doi.org/10.1080/00288330.2017.1393758
Estimation of nutrient loads from monthly water quality data Snelder TN, McDowell RW, Fraser C (Journal of the American Water Resources Association, December 2016) doi.org/10.1111/1752-1688.12492
Research Findings Brief: Assessing the effectiveness of on-farm mitigation actions, Our Land and Water (Toitū te Whenua, Toiora te Wai) National Science Challenge 2020