Using slurry injection is one of the most beneficial and cost-effective ways of getting nutrient-rich dairy effluent back into the soil.
This type of slurry application requires manure to be ground into small particles that can be combined with water to create a liquid, which can then be injected into paddocks, making it less damaging than traditional muck spreading and minimising the need for synthetic fertilisers and reducing costs.
The liquid slurry is injected into the ground and can stimulate boosted production of crops. Slurry injection can allow more nitrogen to be introduced into the soil.
Slurry injection has become a favoured process of application in recent years due to its reduction in ammonia emissions (around 70% reduction), which can preserve nitrogen, reduce odour complaints, eliminate of soil compaction and overall provide a more cost-effective agricultural service solution.
This technique replaces the more traditional method of spraying slurry onto fields using a broadcast spreader, in which the slurry is driven through a nozzle under pressure.
Up to 80% of the available N applied in the slurry by this technique of application may escape into the atmosphere as ammonia. Not only does this lead to the loss of an important nutrient, but it also pollutes the atmosphere.
Thirty percent of the total ammonia loss after surface spreading occurs in the first hour and 80% in the first 12 hours.
Reducing the surface area of the distributed slurry that is exposed to the air is a fundamental strategy to minimise such losses and minimising the area for ammonia to be lost from.
By recycling the effluent on the land, farmers can mitigate these environmental risks and promote sustainable agricultural practices.
When properly managed, slurry application prevents the accumulation of nutrients in water bodies, which can lead to water pollution and eutrophication.
This includes appropriate storage, slurry application rates and timing to avoid overloading the soil, minimising odour issues, and preventing nutrient runoff.
Applying slurry properly and at the right time will minimise environmental losses, ensuring that the crop receives the proper amount of nutrients, and make more nitrogen available for uptake by grass and crops.
This article first appeared in our sister publication, Dairy Farmer.
