A NEW liquid fertiliser additive can help make them work better during the current dry conditions.

BASF’s latest urease inhibitor is claimed to reduce nitrogen loss whilst improving plant nitrogen uptake​ in drought conditions.

Liquid fertilisers are at risk of ammonia volatilisation when it is too dry, but Limus Clear is a risk management tool to be tank-mixed with liquid fertilisers when the risk of nitrogen losses is high. Three ADAS Agronomics trials have shown an average yield response of plus 0.24t/ha when used with liquid fertiliser.

Dry conditions are well known to increase nitrogen losses from granular urea, but it is less widely acknowledged there is also risk with liquid fertilisers. For more than a decade, granular urea users have been able to switch to a urea fertiliser product treated with an urease inhibitor, to reduce losses. Now the introduction of an inhibitor from BASF, means liquid fertiliser users also have the opportunity to manage the risk.

Richard Corden, from BASF, said: “Liquid fertilisers, like UAN, are an excellent source of nitrogen, allowing accurate application and improved workload efficiency. However, it is often not fully understood that nitrogen can be lost after application.

“Up to half of the nitrogen in UAN is derived from urea. As the urea component is converted to plant available ammonium, it is subject to ammonia volatilisation, unless sufficiently washed into the soil,” he pointed out.

“ADAS led a project to evaluate ammonia volatilisation losses from UAN over a three-year period and found that nitrogen losses ranged from 5.5% to 19%.”

Certain environmental conditions, many of which are currently relevant for much of the country, can also increase the risk of ammonia losses, including:

Low rainfall: To minimise volatilisation, more than 10mm of rainfall is required within two days of application to wash the nitrogen into the soil

Dry or drying soil surface: This reduces the diffusion of the nitrogen away from the soil surface

Warm soil temperatures or high soil pH: This speeds up the conversion process resulting in greater losses

These risks can be managed and losses reduced by adding Limus Clear to liquid fertilisers, said Mr Corden.

This new product is available exclusively from Frontier Agriculture and designed specifically for liquid fertilisers. Extensive field trials carried out by BASF have demonstrated that Limus Clear reduces ammonia emissions from urea by up to 98%, minimising nitrogen losses and improving nitrogen use efficiency (NUE).

Ed Downing, Frontier’s crop nutrition technical manager, added: “Nitrogen use effiency is always important, but given the challenging season we’ve had so far, it is perhaps even more so. The high over-winter losses of nitrogen have left little in the soil, meaning we’ll be even more reliant on applied nitrogen than usual to feed our crops.

“Limus Clear is fully compatible with all liquid fertilisers, both straight N and NS grades, is easy to use and low cost,” he added.

A low rate, typically less than 0.2 l/ha (specific for each liquid grade), costing £2-4/ha, is mixed in with the liquid fertiliser during sprayer filling – when soils are moist and sufficient rainfall is expected, you wouldn’t include it.


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