Cleaning up New Zealand’s waterways

Tim Herman, NZPPS Immediate Past President

The New Zealand Government recently announced a programme to clean up New Zealand’s waterways.  This programme is not just targeted at the rural sector – urban waterways are also included. Using Te Mana o te Wai as the guiding principle, the health of a waterway will have priority followed by the needs of the people and, finally, commercial needs.

From a rural perspective the short-term impact is going to be for feed lots and dairy farms, and for fencing off any waterways (streams and wetlands) on all properties. In the medium-term, nutrient levels in waterways will be a focus, particularly Dissolved Inorganic Nitrogen (DIN), but also phosphorus and other nutrients. All farm plans will be required to have a freshwater module and there will be limits on synthetic nitrogen inputs for pastoral farms (horticulture has a period of reprieve at present).

What does this mean for plant protection?  

Improved nutrient management could lead to improved pest, disease and weed control as excess nutrients in crop/pasture are known to exacerbate pest, disease and weed issues. The horticultural and arable industries are already improving management of synthetic nitrogen fertiliser through the use of rapid testing of soil samples and knowledge of crop nitrogen needs.

Fenced off riparian strips could provide an opportunity to enhance populations of natural enemies and other beneficial organisms. This depends on the plant species chosen for planting in the riparian strips.Other than that, there are surely plenty of research opportunities to study how these changes are going to impact plant protection into the future.