Cumbrian dairy farm sees high payback from slurry booster

He says he’d tried bacterial additives for his slurry before but the products he used had no apparent effect.

“We tried several different products, some in sachets you had to mix, but they did nothing at all and we felt we were wasting our money,” he says.

However, when he tried Digest-It he says the benefits were obvious, both in the tank itself, when spreading the slurry, and finally, when he had his slurry analysed, before and after treatment.

This analysis is shown in the table above indicates a 24.5% increase in the nitrogen value and a 22.5% increase in the total nutrient value some six weeks after the slurry booster was added.

“We have bought less fertiliser so far this year which is both due to the Digest-It and of course the high prices,” he says. “We will review this later in the year, although can’t say exactly how much we will need to buy until the grass starts growing.”

In addition to the fertiliser saving he says he has also saved on fuel.

“We have a 100,000 gallon slurry tower and always had a problem with the crust,” he says. “When it was full, we had to remove about a dozen loads of water from under the crust before we could even stir the tank.

“If we didn’t, it would lap over the top, and even after we’d removed some slurry, it would take at least two hours to stir,” he says.

However, he was not expecting his slurry to need no stirring at all after adding the booster, but this is what he found.

“Without even stirring, we find the consistency of the slurry now to be completely even, right through the tank,” he says.

“This means it is also spread evenly and I’ve noticed when spreading there is not the same smell.” This reflects the reduction in ammonia which is captured and converted into organic nitrogen rather than given off as gas.

Today, the farm continues to use Digest-It in a routine which involves pouring 20 litres into the slurry tower when it’s nearly empty and adding five litres every week to the reception pit, until the tower is full. When it is emptied again a small amount of slurry is left in the bottom of the tower to retain a culture of the bacteria which are evidently doing such a good job.

The financial return on investment from the product on this farm, measured in the nutritional improvements to fertiliser alone, has been calculated at 4.6:1 at today’s fertiliser prices – and that’s without any consideration of the savings in diesel for stirring.