How Slurry Gold Works

Slurry Storage Management – The Problem

As slurry is a natural “living” product, storing it in static systems results in a number of unnatural side effects, thereby deteriorating its fertiliser value and increasing management costs to the farmer. These include:

Crust formation: Undigested plant fibre material is made up of light particles which float to the surface where they dry out and compact to form a crust. The crust causes a physical problem when emptying the pit but more importantly it prevents oxygen and light entering the lagoon resulting in low microbial activity to breakdown the manure solids.

Odour / Gaseous emissions: Fresh cattle manure has a less offensive odour than stored slurry because of the subsequent anaerobic fermentation in the lower layers of the lagoon. This is made worse by any crust layer that may form. These conditions result in the production of ammonia and hydrogen sulphide together with particularly noxious compounds resulting from protein breakdown such as putrescine and cadaverine. Other gaseous compounds released from slurry include methane, nitrous oxide & carbon dioxide.

Nutrient Losses: Losses of potassium and phosphorus during storage are minimal. However, significant amounts of nitrogen can be lost from slurry before it can be applied as a source of fertiliser. Nitrogen in fresh slurry is principally in the form of urea. Within the tank/lagoon this is eventually converted, through a number of intermediates, to nitrate as per the chain below:


The rate limiting step in this cycle is the oxidation of ammonia to nitrate. This is a slow reaction greatly affected by temperature, pH and other chemicals in the waste. Urea converts to ammonia rapidly, upsetting the equilibrium and the excess ammonia is liberated into the environment. The conversion of urea to ammonia is the most rapid stage. This results in a build-up of ammonia which is highly volatile and escapes from the lagoon at the liquid:air interface. This is the principal reason for such large losses of nitrogen from manure and the reduction in its value as a fertiliser.


SLURRY GOLD has been designed to overcome these disruptive side effects during slurry storage. Its aim is to achieve:

– Improved oxygen levels, at least in the upper strata of the tank/lagoon
– Deeper penetration of light and oxygen into the lagoon to minimise anaerobiosis
– Accelerated levels of fibre digestion through enzymatic or microbial action
– Enhance rates of organic waste degradation and solubilisation
– Reduced ammonia emissions by accelerating the microbial conversion of ammonia into nitrates
– Improved assimilation of nitrogenous compounds into organic forms and ultimately microbial biomass

Through identifying a unique microbial formulation of bacteria, enzymes, stimulants and surfactants, SLURRY GOLD has the capability to maintain a healthy ecology within the slurry enabling the above to be achieved.

Improved nutrient uptake

SLURRY GOLD achieves enhanced nutrient retention during storage by both creating an optimal environment to support healthy microbial activity, and by adding specific bacteria to target certain processes that optimise the transfer of nitrogen into a stable nitrate. As crust formation is minimised, this allows light and air to access the slurry. This supports a healthy aerobic environment where microbes can work as nature intended. Such activity is boosted by the addition of specific bacteria that slow down the production of ammonia from urea yet enhance the production of nitrate from ammonia. This ensures nitrogen is recycled as efficiently as possible.

Reduced crust formation

Slurry storage commonly results in the formation of a thick crust on the surface along with a slow degradation of solids. To deal with this, farmers will frequently mix the slurry whilst in storage. However, with modern farming focusing on high efficiencies such a job could be avoided thereby saving on labour and fuel costs. By using SLURRY GOLD a more stable product is retained resulting in minimal crust formation and a more dilute product. As well as saving on mixing requirements it will help with spreading as a more equal distribution of slurry can be applied. Click here for an example of how crusting was simply prevented for one farmer.

Reduction in polluting odours

Slurry is well known to be a source of polluting gases such as ammonia, methane, hydrogen sulphide and nitrous oxide. All of the e are recognised as affecting climate change. As farming has to reduce such polluting outputs, SLURRY GOLD is in a unique position to help in a simple way. By keeping the slurry “alive” in storage the production of such polluting odours are greatly reduced. As SLURRY GOLD has been designed to lock in Nitrogen in the form of ammonia nitrate, less ammonia gas is produced. Similarly as the biological activity is kept healthy in the slurry, less noxious and degrading gases are produced.

With this in mind, by using SLURRY GOLD, we would never abdicate a less disciplined approach to safety when mixing slurry. For more details on safety with slurry, click here.

Enhanced soil fertility

A healthy soil requires air, water, nutrients and biological activity. This is not helped by spreading thick inactive slurry on the surface where air intake can be reduced and a slow degradation results in reduced biological activity and nutrient release. Slurry treated with SLURRY GOLD will soak into the soil much quicker. As it is already full of biological activity and increased nutrients, uptake into the soil and crops will be much improved. Thus, promoting the long term fertility of the soil.

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