We report on trends in nitrate-nitrogen from livestock that has leached from soil per year across New Zealand since 1990.
Nitrogen is an essential nutrient for plant growth. It occurs naturally, but in agricultural systems more nitrogen is commonly added to soils as fertiliser or as urine or dung from livestock. Not all the additional nitrogen can be used by plants and microorganisms, so some nitrate-nitrogen may leach (drain) from the soil. Livestock urine is the dominant source of nitrate-nitrogen leached from soil. Leached nitrate-nitrogen can enter groundwater and waterways, potentially causing ecological harm. The amount of nitrate-nitrogen leaching from the soil varies around the country as a result of different land uses, climates, and soils.
More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.
Summary report available at http://www.mfe.govt.nz/publications/fresh-water/spatial-nitrate-leaching-extent-update-environmental-reporting