Slurry applied on dull and dry days in January and February gives the biggest grass yield the following year, according to Alan Kerr of Low Dallars Farm, by Kilmarnock.

Alan is concerned that if a ‘closed period’ was to come in which prevented the spreading of slurry in winter, then Ayrshire would turn 'black' the day the restrictions were lifted. His preferred method would to be able to spread little and often across the year as he believed the ground is better able to absorb the slurry and grass can better utilise the nitrogen by doing that.

New slurry storage requirements coming in for Alan’s dairy farm's means he has to increase his capacity from three months to five months. Alan and his brother, Brian, have four years to comply with their 380-cow pedigree Holstein herd spread over two farms.

Previously, the business applied for a £30,000 grant to install two new slurry towers at the two farms. This would have increased the storage from 400,000 gallons at each farm to over 1.2m gallons. However, the grant system would not allow them to split the grant over the two farms, or take the grant on one farm without an upgrade at the other. So they kept their current system in place.

Since the farms are seven miles apart, they now need a solution on each site to comply with the new regulations. The price in 2018 at the time of application was around £100,000 for each store, however prices of materials and demand has risen since so Alan is expecting to have to pay a lot more to increase his slurry capacity now.

“We are currently waiting for a better grant scheme to come out so we can upgrade the two farms,” explained Alan. “We need a grant scheme which is flexible for businesses which are split over different units.”

Spreading the Low Dallars slurry is through an umbilical system which the farm has been running for 15 to 20 years. The farm switched from a splash plate to a dribble bar in 2012, which was then upgraded to a new Slurryquip machine through last year’s round of government capital grants.

The business also got grant aid on an auto steer and flow meter, which Alan reckoned had been a real benefit to spreading the right amount on the right places.

“The flow meter has really helped application of the slurry,” explained Alan. “We now know the amount of slurry going onto the fields.

"It sounds obvious but there was a lot more slurry going on at the bottom of the field than the top, as the pump didn’t have to work as hard. But previously I would drive at the same speed. Now I vary the speed of the tractor so the flow rate remains fairly constant.

"The meter tells us the amount we are applying per hectare which greatly benefits evening out grass growth in fields.”

As a result, the brothers have made a massive reduction in fertiliser purchased, which is has made significant savings this spring given the rapid rise in cost of nitrogen.

This year the silage ground received only 30 units of N per acre from bagged nitrogen, plus slurry and digestate. The digestate comes from food waste and in liquid form, which is added to the slurry before application. “It is pokey stuff,” said Alan. “It certainly makes the grass grow.”

The digestate does cost a fee, which has been rising in recent months due to increased demand from other farmers looking to reduce reliance on bagged fertiliser.

Alan has been using it for eight or nine years now and has seen it almost triple in price since the start. But with fertiliser at strong prices, he believed it to be still good value.

On Tuesday, Alan received 14mm of rain in the afternoon but as soon as it dries up, plans to make silage. On his first cut, he hopes to yield a fresh weight of 10 tonnes per acre at a D-Value in the high 70s and a protein level of between 16 to 18%.

Spreading the slurry using the umbilical system, Alan has a 160hp John Deere tractor fitted with wide low ground pressure tyres with a smaller tractor on the pump. Ground further away from the farm is fed by 2500 gallon ferry tankers to a dump station then spread with the umbilical system.

Typically, he would hope to spread between 25,000 to 30,000 gallons per hour, with a good day being able to spread 200,000 gallons.

Because he is not in an NVZ, he goes often throughout the year when it is dry and conditions are right. “We don’t wait until we are totally full and it is fire brigade stuff,” Alan explained.

“I think the ground benefits from it, getting drip fed over time. The best acres of first cut silage are from the fields which get a application of slurry in January and February each year. Compared to the fields which only get it in March, it is night and day.”

After the first cut of silage, the ground gets an application of slurry and digestate. Then, after the second cut, the fields only receive slurry for the later crops.

"With the number of cows we have, we are never short of slurry, so it's all about making best use of it as it's a very valuable source of fertiliser and not just the waste product it used to be."

He feared that the next step would be to move to a closed period, like Ireland, and then there will be too much applied too quickly once the closed period ended. Which would not be good for the waterways, or maximising plant growth.

Alan added: “This would be a lot more than farmers working away quietly in winter when the conditions are right. We never spread slurry in the rain.

"If we were closed until the end of February, then first week of March the west of Scotland would be black with slurry ... it is an environmental disaster waiting to happen.”