Nitrogen Losses from Land
Key Points | Report Card | Technical Information | Data
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What is happening in our region
Our research shows that nitrogen loading into rivers from developed land (non-point sources) in this Region is closely related to the average stocking rate of dairy cows (view graph). This is because nitrogen in animal urine moves very easily through the soil and groundwater. This makes it possible to use an area’s dairy cow stocking rate to estimate the nitrogen loading into waterways. The information on nitrogen loading in this indicator has been estimated from each area’s dairy cow stocking rate.
- Nitrogen loading is generally low in the less developed upland areas of the Region, such as the area around Lake Taupo.
- In the more developed lowland parts of the Region, nitrogen loading is often moderate to high. Intensive agriculture - both dairy farming and cropping - is the main source of increased nitrogen loading to the Region’s water.
The graph shows the percent of river catchments in different parts of the Region, which have ‘low’, ‘moderate’, or ‘high’ estimated levels of nitrogen loading.
- View this graph’s data. This graph is based on information from the 1997 Farm Dairy Effluent Database.
- Find out more about nitrogen levels in our waterways.
Why nitrogen loss is important
This indicator is based on the amounts (loads) of nitrogen getting into our water, either through subsurface runoff (leaching) or surface runoff. Nitrogen is a plant nutrient. High levels of nitrogen in our water can support nuisance growths of water plants and algal blooms (including slimes in rivers).
Some of our highest quality water bodies, such as Lake Taupo, are very sensitive to inputs of nitrogen from the surrounding land. The indicator provides a way of telling which water bodies are likely to be at risk from high nitrogen inputs.
What Environment Waikato is doing
- Environment Waikato provides clear management guidelines for discharging dairy farm effluent onto land.
- We support Care groups involved in riparian (stream bank) management such as planting and fencing.
- We provide environmental information including practical land management guidelines.
- Environment Waikato's Clean Streams project provides advice and financial support to encourage and support farmer efforts to reduce the impacts of farming on waterways through fencing and planting waterway margins.
- Environment Waikato is also in the process of changing our Proposed Regional Plan to manage the amount of nitrogen getting into Lake Taupo from land use in the catchment.
- We support voluntary guidelines and codes of practice such as the NZ Fertiliser Manufacturers' Research Association’s Code of Practice for Fertiliser Use (code of practice).
Find out more about the water provisions in our Regional Plan.
What you can do to help
- Fence off streams, rivers, swamps, wetlands and seeps to prevent stock access.
- Plant banks of waterways to help stabilise the banks and trap nutrients.
- Follow our guidelines when applying dairy farm effluent to land.
- Make sure dairy shed effluent irrigators are operating effectively and are moved frequently to prevent ponding and runoff into waterways.
- Avoid break-feeding or mob-stocking close to waterways, especially in wet weather.
- Form a Care group with your neighbours to discuss and implement better land management practices to protect your local river and stream.
More information
More detail on this indicator, including how and where Environment Waikato collects this information, is available in the Technical Information page.
Useful links
Related indicators