Offset high fertiliser prices by making best use of nutrients in slurry
Making best use of the nutrients in slurry can cut the amount of purchased fertiliser needed, providing a crucial opportunity to improve the bottom line as input costs continue to squeeze margins.
Slurry is a resource that livestock farmers have readily available and its nutritional value and utilisation can be enhanced through good management and the addition of a biological slurry inoculant.
It’s a huge opportunity currently, with the price of artificial nitrogen (N) so high, and it will remain relevant even if fertiliser prices fall again.
Treating slurry with an inoculant can increase the available N content by up to 20 per cent depending on the slurry’s initial composition, while reducing the amount of ammonia being released into the air. This is increasingly important given the Government’s target for the agricultural industry to reduce ammonia emissions by 16 per cent by 2030.
During an on-farm trial in a slatted dairy housing system from November 2020 to February 2021, slurry treated with the biological slurry inoculant SlurriN PRO reduced ammonia emissions by up to 65.2 per cent.
The specific blend of enzymes and bacteria in SlurriN PRO help improve fibre breakdown during slurry storage, providing a nutrient source to the microbes in the inoculant which gives them a competitive edge.
As a result, the organic N content of the slurry is increased, this form of N is not volatile or leachable and as the organic N mineralises it becomes available to the soil and to the plant.
Farmers that are treating their slurry with an inoculant are seeing the benefits in terms of improved available N.
There can be a significant variation in the nutritional value of slurry and by taking steps to increase the slurry dry matter (solids), its financial worth can be considerably increased.
One agronomist trial based on a Shropshire farm found that the N content of the slurry went from 1.28kg/m3 to 1.75kg/m3 following treatment with SlurriN PRO, which is worth £40 per ha in terms of N and S inputs.
One sachet of SlurriN PRO treats the equivalent of one months’ slurry production from 100 dairy cows. The inoculant should be applied to slurry once a month by mixing the required SlurriN PRO into 10 litres of water and pouring this directly into the store.
Farmers should also make sure there is enough capacity to store slurry for up to four months, offering flexibility to spread when conditions are optimal, increasing the fertiliser value and reducing the risk of water pollution.
Lientjie Colahan is Lallemand Animal Nutrition product manager
