Mary Kingston: Our fertiliser calendar restrictions are not fit for purpose

Farmer spreading slurry in a field
Farmer spreading slurry in a field

Mary Kinston

With limited rainfall in early January, I've seen the odd social media post about our daft calendar restrictions on slurry spreading whilst ground conditions are good.

The policy is a widespread restrictive approach to minimise nutrient leaching. It has minimal consideration for the differences between farms - for example, soil types.

It's simple and farmers comply - but is it effective?

Our progress in future water quality will be the testimony to that but it's certainly stifling in terms of management and practicality. This issue was brought to my attention whilst in New Zealand visiting family and old work colleagues, when in conversation with Charlotte Glass, who is managing director of Agri Magic. Agri Magic provides farm system solutions to nutrient management restrictions.

Charlotte outlined that New Zealand has taken the option to implement an effects-based policy and there are many paths to achieve the same outcome.

In essence, by accounting for specific circumstances on farm through nutrient budgeting with the most up-to-date research and principles, this process protects the desired outcome rather than dictating the practices to achieve change. Here, ingenuity and innovation rely on a respect for the differences between principles (why) and practice (how).

New Zealand's regulations in dairying in relation to nitrogen and phosphate limits have certainly increased tenfold since I moved to Ireland. Before I left, they had started to use Overseer.

Overseer is a software programme used to model nitrogen cycling on farm. However, the process was somewhat in its infancy of development and implementation.

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Thirteen years on, regional councils demand it in line with the Resource Management Act 1991 and milk companies make sure that NZ farmers comply and determine their nitrogen loss and nitrogen conversion efficiency annually.

They need to have documented proof of what they are doing by taking account of the farm characteristics, the stock, feed and fertiliser use.

Whilst focus is still primarily on leaching of nutrients from the system, farmers now have to prove that they are not increasing their nutrient losses since the base level of 2009-2013, depending on the regional council.

Regional councils across NZ have set quality limits on all ground and surface water bodies, with many required to reduce losses by 30pc by December 2030. Focus is put on nutrient leaching hot spots such as winter cropping, fertiliser application, effluent and irrigation, grazing and the management of stock over the winter.

They refer to off-paddock facilities, which could be stand off or wintering barns.

Even for the New Zealand farmer, this is a somewhat daunting prospect.

It's clearly impacted areas with free draining soils with irrigation as there seem to have been fewer conversions into dairying in recent times. It is also now impacting land values, with high base levels attracting greater values due to the ability to use these land parcels for more enterprises than lower base levels.

One can only assume that research suggests that a change in system will increase the potential leaching due to the inputs that go with such a system.

However, rather than a policy that caps stocking rates, inputs and application dates, this effects-based policy does offer the farmer strategic opportunities to focus on the feed harvested and drive efficiency through less imports, thus nutrients and higher feed conversion, thus nitrogen conversion efficiency.

The aim being the most efficient use of the resources available to them, which will inevitably reduce loses.

Essentially it's just the same considerations one should make when the milk price is low.

However, my old colleague assured me that it isn't without its headaches because as the research information changes, farmers also have to engage and continuously adapt to such change in the numbers and potential impacts.

As an industry, it also has challenges for all bodies to work together because the impacts are cross-sector (not just dairying). All things considered though the effects-based policy is potentially a better option than our rules.

Luckily for New Zealand farmers, there is still an opportunity to use nutrient management advisors to scientifically work through the constraints to find a farm system that limits nutrient leaching but allows farmers to determine how they should operate in the most environmentally-friendly way.

Mary Kinston is a discussion group facilitator and consultant, and farms with her husband in Co Kerry

Indo Farming

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