UK - How crop science and healthy soils can reduce costly farm chemical use

Smart science and decades of soil-friendly cultivation are helping optimise the use of costly fertilisers on a Norfolk farm - hailed as a "win-win" for both farm finances and the environment.

The efficient use of nitrogen fertilisers has been thrown into sharper focus in recent weeks after costs soared to £1,000 per tonne due to rising gas prices, compounded by the war in Ukraine.

But there is also an environmental cost. Nitrogen can be lost into the air as ammonia following the application of liquid fertiliser, and the risk increases with warm temperatures and dry soils - increasingly a feature of the East Anglian springtime.

So Kenningham Hall Farm in Mulbarton has been using a "urease inhibitor" to improve the uptake of nitrogen into its plants, and reduce ammonia emissions.

Norfolk farmer Nick Gowing, centre, discusses crop nutrition with Edward Downing, left, and Andrew Melton of Frontier Agriculture at Kenningham Hall Farm at Mulbarton - Credit: Denise Bradley

Farmer Nick Gowing said he hoped the product would make his fertiliser go further - reducing costs, improving yields and limiting the potential for pollution.

"In simple terms, it is about cost-effectiveness and efficiency," he said.

"If we are talking about the price of fertiliser at the moment, this product is quite cost-effective because it helps us not to waste what we put down.

"We put on fertiliser for sugar beet, pre-drilling, on bare soil, we also used it on spring barley post-drilling, again on bare soil.

"We are talking about reducing it, but we are doing fewer passes with the machines in the field and banging on a bit more fertiliser in one go, so we want to know that amount will get into the soil and be available for the plant. We are putting all our eggs in one basket, so we need to reduce the risks of that.

"We are all getting fixated on cost at the moment, but the environment is just as important, and always will be."

The 250ha farm, which also handles contract work on another 800 hectares, has worked for 20 years to develop a long soil-friendly rotation with regular use of cover crops, and predominantly minimum tillage and direct drilling.

Muck spreading at Kenningham Hall Farm at Mulbarton - Credit: Nick Gowing

It also uses farmyard manures, supplied by nearby beef and dairy farms, on "some land in most years" - although Mr Gowing said this is much more effective at replacing phosphorus and potassium nutrients, as only a small fraction of nitrogen is available to the crop.

Andrew Melton is regional agronomy sales manager for Frontier Agriculture, which supplies the urease inhibitor product, called Limus Clear.

"It is a win-win for everyone," he said. "If you are not wasting product you are saving money. So the two things are completely linked.

"The biggest things that Nick has done over 20 years, that have had an impact both financially and environmentally, goes back to having a sustainable rotation, appropriate tillage, and incorporating cover crops. The soil on his farm is as resilient as it could be.

"If the soil and roots are in good order then everything else we do, in this case optimising the liquid nitrogen, is giving us a greater chance for that nutrient to be used to the best of that plant's ability.

"And if we get that part right, then the environment will benefit as well. They go hand in hand."

Norfolk farmer Nick Gowing, centre, with Edward Downing, left, and Andrew Melton of Frontier Agriculture at Kenningham Hall Farm at Mulbarton - Credit: Denise Bradley

Edward Downing, Frontier's national crop nutrition technical manager, said field-scale trials by research consultancy ADAS showed the product increased average yields by 0.23 tonnes per hectare.

And he agreed that "efficiency will always benefit both the grower and the environment".

"We didn't start the conversation about nitrogen use efficiency when nitrogen fertiliser hit £1,000 a tonne," he said. "I have been talking about it for ten years. It is valuable at whatever cost.

"It is the ultimate win-win, because if you get that right, you use the least amount of nitrogen to grow the best amount of produce with the least impact om the environment.

"But the cost has really focused people's attention, and you see an increase little things like the amount of people who are sending manures away to be sampled to see what is in them.

"To me, that is a positive. It has got people thinking: What is the value of that? What is that bringing to this farm?"