Nitrogen Fertiliser in NZ: Can You Use Less Urea and Grow More Dairy Pasture?
Urea works. Farmers know it works, and Agraforum is not pretending otherwise.
The question is whether every nitrogen round has to come out of a urea bag.
Agraforum BioN gives farmers another way to supply nitrogen through the warmer part of the season. We now have completed New Zealand dairy pasture trials showing what happened when Agraforum BioN was put alongside urea.
We thought Agraforum BioN worked. Gordon made us prove it.
When Allan first tried Agraforum BioN on a few paddocks, it looked promising.
Dr Gordon Rajendram was not prepared to call that proof. Gordon had spent 22 years at AgResearch, and his view was that the only way to know was to run proper replicated trials.
At each site, 30 plots were randomly positioned in the same paddock area: ten Agraforum BioN, ten urea and ten untreated controls. The pasture was cut, weighed and independently analysed for dry matter. That matters because one paddock can look better than another for all sorts of reasons. Randomised, replicated plots let you measure the treatment rather than the luck of where it was applied.
Agraforum BioN grew 9.6% more cumulative dry matter than urea
Across Agraforum’s completed Mid Canterbury trial programme, Agraforum BioN averaged 17,173 kg DM/ha compared with 15,666 kg DM/ha for urea.
That is 1,508 kg DM/ha more pasture, or approximately 9.6% more cumulative dry matter with Agraforum BioN.
The other important difference was frequency. Urea was applied after every cut. Agraforum BioN was applied every eight to nine weeks through the warmer months, roughly every third cut.
Agraforum BioN was applied far less often and still grew more pasture in the trials.
The trials also taught us how important application conditions are.
In the first year, Agraforum BioN was sometimes going onto ground below 12°C and without enough water. The bacteria were not being given the conditions they needed to get established properly.
In year two, the protocol changed. More water was used to mimic rain or irrigation and Agraforum BioN was applied in warmer conditions. The response improved markedly.
That is why the advice now is straightforward. If the farm is still cold, wait. If pasture is moving and moisture is available, that is when Agraforum BioN starts making more sense.
How does Agraforum BioN supply nitrogen?
The air above every paddock is about 78% nitrogen, but pasture cannot use nitrogen gas directly.
Nitrogen-fixing bacteria can convert atmospheric nitrogen into forms plants can use. That process is called biological nitrogen fixation. Agraforum BioN introduces those bacteria into the soil. So it is not a nitrogen-rich fertiliser in the conventional sense. You are not applying a large load of nitrogen in the product itself. You are using biology to make more use of nitrogen that is already in the atmosphere.
Can Agraforum BioN replace urea?
Yes, Agraforum BioN can replace urea rounds when conditions suit.
That does not mean urea suddenly has no place on farm. When soils are cold or a quick nitrogen response is needed, synthetic nitrogen can still be the right tool.
The Mid Canterbury trials do show that every round does not necessarily need to come from urea. Agraforum BioN was applied every eight to nine weeks while urea went on after every cut, and Agraforum BioN still grew more cumulative pasture. For farmers looking for an alternative to urea, that is the useful part of the result.
What do fewer applications mean on farm?
Another nitrogen round costs more than just the product itself. It takes time, machinery and another pass across the farm.
Under suitable conditions, Agraforum’s guidance is at least eight to ten weeks of plant-available nitrogen release from one Agraforum BioN application. That lines up with the trial programme, where Agraforum BioN was applied every eight to nine weeks through the warmer months.
Fewer applications can reduce the work attached to the nitrogen programme as well as reducing reliance on repeated urea purchases.
Eight weeks without urea on farm
The trials give us measured data. Farmer experience shows what Agraforum BioN can look like in a working programme.
New Zealand dairy farmer Dion Gordon went eight weeks without applying urea, with Agraforum BioN carrying the pasture growth through that period.
As Dion put it: “Over an eight-week period we didn’t put any urea on at all. Agraforum BioN carried the growth right through.” His experience is consistent with what the trials found: longer gaps between Agraforum BioN applications did not mean less pasture.
Taupō and Rotorua: a different nitrogen conversation
For farms around Lake Taupō and Lake Rotorua, nitrogen planning can be tied to catchment-specific rules and property-level requirements.
Agraforum BioN does not change those rules. What it gives farmers is another way to supply nitrogen through the warmer months without adding synthetic nitrogen units directly to the farm system.
That can be particularly useful where the farm is trying to reduce reliance on repeated synthetic nitrogen applications while maintaining pasture growth.
Wium Mostert looks after Agraforum across the North Island and can talk through how Agraforum BioN could fit alongside the programme and requirements already in place.
So, is Agraforum BioN worth looking at?
If you are happy with your current nitrogen programme, its cost and how often you are applying it, there may be no reason to change anything.
If you are trying to reduce urea rounds, keep more synthetic nitrogen in reserve or simply want another option through the warmer months, the Agraforum BioN trials give you something solid to work from.
Agraforum BioN grew more cumulative pasture than urea in the completed trials while being applied much less often. To talk through what that could look like on your farm, call Allan or Mike on 0800 488 118.
Common questions
What is a biofertiliser?
A biofertiliser uses living microorganisms to help make nutrients available to plants. Agraforum BioN uses nitrogen-fixing bacteria to support biological nitrogen fixation in the soil.
What is biological nitrogen fixation?
Biological nitrogen fixation is the process where microorganisms take nitrogen from the atmosphere and convert it into forms plants can use.
Is Agraforum BioN an alternative to urea?
Yes. Agraforum BioN can replace some urea applications when conditions suit. That does not mean synthetic nitrogen has no place in the programme.
How often is Agraforum BioN applied?
Agraforum’s guidance is an eight to ten week nitrogen release period under suitable conditions. In the completed Mid Canterbury trials, Agraforum BioN was applied every eight to nine weeks through the warmer months.
Does Agraforum BioN count towards the synthetic N Cap?
Agraforum BioN does not apply synthetic nitrogen units and so doesn’t count towards your N Cap.
What did the trials show?
Across the completed Mid Canterbury trial programme, Agraforum BioN averaged 17,173 kg DM/ha compared with 15,666 kg DM/ha for urea. That is approximately 9.6% more cumulative dry matter.
Want to know what Agraforum BioN could look like on your farm?
Call Allan or Mike on 0800 488 118.
North Island farmers can also call Wium Mostert on 027 463 7577.
Visit agraforum.co.nz to read the Agraforum BioN trial data.
