STOCK farmers are being encouraged to take a look at introducing a slurry inoculant in the winter housing period to reduce ammonia emissions and increase nitrogen use efficiency (NUE).

With 2030 government targets to reduce ammonia emissions from agriculture by 16%, the use of biological slurry treatments had been highlighted as an extremely viable option, said Lientjie Colahan, a technical sales support specialist at Lallemand Animal Nutrition.

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“When slurry is spread, a process called volatilisation can happen, which means that ammonium N (NH4+) is converted into ammonia (NH3) and is released into the atmosphere,” she said.

“However, treating slurry with a biological inoculant can reduce the ammonium in the slurry and increase the organic nitrogen content which results in less ammonia production.”

This had been proven in a recent trial, she pointed out. “From November, 2020, to February, 2021, a trial was carried out in a slatted dairy housing system showed that slurry inoculated with SlurriN PRO reduced ammonia emissions on average by 36.5%, improving air quality within the shed.

“There were further benefits. The organic nitrogen content of the slurry was also greatly improved and with more nitrogen being incorporated into the bacteria’s cells there is less opportunity for nitrogen leaching after the slurry is spread. This form of nitrogen is also rapidly available to the plant,” she said.

With the correct application of the inoculant, its specific blend of enzymes and bacteria could improve the consistency and ‘workability’ of slurry, which will in time reduce the fuel and labour costs associated with slurry management.

Mrs Colahan notes that to maximise the benefits of the inoculant, it was crucial to start treatment ahead of winter housing, at best prior to new slurry being added to the pit.

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“The simplest and most convenient way of applying the inoculant, if the slurry store only has a small amount of residual, slurry, is once a month. Mix a 1kg sachet of SlurriN PRO into 10 litres of water and pour this directly into the slurry store. This process should be repeated every month, for the duration of the winter housing period.”

The trial is the first of many that Lallemand planned to undertake, with the hope to further encourage dairy farmers to take full advantage of the benefits that improved slurry management has to offer.