In travelling through the North Island of New Zealand, it can be seen that livestock production, primarily dairy, is a key enterprise driving the agricultural economy. With an increase in density of dairying across the North Island there are increasing nutrient management issues that land managers are being very closely monitored for.
The North Island in many dairying areas has approximately 1200mm rainfall per annum, which falls relatively regularly throughout the year. With relatively high stocking densities, nutrient management from manure effluent and synthetic fertilisers is a major issue facing land managers. Due to the soils being free draining there is a high leaching rate and in high rainfall events farms will have high rates of surface runoff. This has resulted in regulated waterway management and water contamination has become a primary focus issue.
Nutrient budgeting is now enforced in the North Island for dairy enterprises. This has enforced the limiting of stock access to water ways, in order to reduce direct contamination to not compromise water quality for the respective catchment areas.