An official press release on 10th June 2026 from Agriculture Minister Todd McClay stated that the government has invested “$3.55 million in a $8.47 million five-year project to boost beef and sheep production, and $18.34 million on a $45.85 million seven-year project to grow dairy output with improved environmental outcomes.” (Read Press Release here)
Also noted in this press release is the government’s intention to deliver a 20% reduction in nitrogen leaching per hectare as part of the dairy project.
The simplest way to achieve this goal would be to continue to limit nitrogen use via the N-Cap rules and regulations we already have. However, while this strategy might improve environmental outcomes, it’s unlikely to grow dairy output since nitrogen is essential for our pasture-based system in NZ.
A far better alternative would be to consider the type of nitrogen products being applied, and look for options that can reduce leaching while still growing grass.
Fortunately, such nutrient-efficient products do exist and Fertco’s polymer-coated urea (PCU) is the perfect example of this.
What is PCU?
PCU is a controlled release fertiliser, manufactured by coating granules of urea with a biodegradable coating. The purpose of the coating is to protect the nutrients inside the granule so that they are gradually released into the soil.
How PCU works
PCU releases its nutrients when soil moisture penetrates the coating of the granule and starts to dissolve its contents. This causes the granule to swell and pressure to develop inside the granule. With the increased pressure, the dissolved nutrients move out into the soil through pores in the coating which have a fixed size. When the pressure eventually drops inside the granule, the coating degrades away.
Note that this process can take up to three months, and that the nutrient release follows a controlled pattern.
How urea works
In contrast to PCU, urea is very soluble. So it releases its nutrients rapidly. As soon as it comes into contact with soil moisture and soil microbes such as urease enzymes and nitrifying bacteria, the nitrogen in the urea is transformed into plant-usable ammonium (NH₄⁺) and nitrate (NO₃⁻).
Whereas nutrient release in PCU occurs over months, the pattern of nutrient release for urea typically occurs over days.
Moreover, the nitrate ions have a negative charge so are poorly held by the soil.
This can all result in more nitrates being available in the soil solution than plants can take up. And it’s exactly the situation that promotes nutrient leaching.
Soil nitrate surplus
It’s easy to see how a surplus of nitrates in the soil can develop in the late autumn, winter, and early spring months. On the one hand, temperatures are down, so plant requirements are low. On the other hand, soil moisture levels are high from rain.
So a fertiliser like PCU that can ration out its nutrients in sync with soil moisture levels and plant growth demand is a great start to reducing environmental damage from leaching.
Increasing dairy output
Note that it’s not just leaching that the government aims to address. There’s also the matter of increasing dairy output. As a nutrient efficient fertiliser, PCU can also play a part in growing dairy output.
Because PCU is more efficient, and nutrient availability matches plant growth demands more closely, more of what is applied gets used as intended. Leached nutrients result in wasted money and resources to boost pasture and crop growth.
With PCU, repeated applications aren’t necessary because the nutrients are around for longer. So cartage and spreading costs are reduced. Another benefit lies with the encapsulated granules: they’re more accurate and safe to handle and spread.
Encourage PCU
So, in response to the government’s aims for the dairy industry to reduce leaching by 20% per hectare while increasing dairy output, we at Fertco urge serious consideration be given to encouraging the use of controlled release fertilisers like PCU.
This article was published in the Coast & Country News.
