As fertiliser and inputs reach record highs it has never been more important for farmers to ensure every prill and litre of manufactured product is utilised by the plant.

Strategic application and good soil health are vital for grassland farmers who face a challenging year in the face of spiralling costs. Grassland expert, Rhidian Jones, from Five Agri and livestock farmer, Andrew Marchant, spoke to The Scottish Farmer on their plans to cope with spiralling fertiliser costs in the coming season.

Rhidian believed that, despite the sharp rise in fertiliser costs, it was still worth applying – but farmers need to target application to where nitrogen would be most affective.

Read more: Farm efficiency: How not applying N can transform fertiliser use

He said: “Even at the current costs of fertiliser, it still has a part to play in grassland farms. If you get a response of over 7.5kg of DM to every kg of N applied, then it is good value when compared to buying feed at £300per tonne on to your farm.

"Urea at 46% N for is currently trading at £920 per tonne, which is the equivalent of £2/kg of N. So it makes sense to put on fertiliser if you are yielding a decent crop of eight tonnes per acre (or 20-tonne per ha) fresh weight silage. At a 25% DM, it would result in two-tonnes of DM/acre, or five tonnes DM/ha.

"But farmers should also be mindful that not all of the grass yield is down to the chemical nitrogen applied – some will be from clover, or mineralisation of soil organic matter and some will just be there anyway.

“To maximise response from nitrogen on grassland you should have a pH of over 6. You also need to look at the types of grasses you have, as older leys with weed grasses will have less a response than species such as rye grasses, cocksfoot and Timothy," he pointed out.

"Older grasses might go green after putting on fertiliser, but the dry matter won't be there. Perennial ryegrass can have a response close to 100%, Yorkshire fog 42%, bent 33% and meadow grass 17%.

“Ideally, you would have tested your soil in winter but it is still not too late now. You can get a basic test looking at pH, phosphorus, potassium and magnesium back within three to four days. If you are looking for a more detailed report involving trace elements, it is likely to be more than a week."

Rhidian recommended that farmers should continue to be strategic with application and not be scared to apply smaller amounts more often when the grass can best utilise it.

Focusing applications on south facing fields is also a good idea as they will give a response first, but Rhidian recognised this was not easy particularly when contractors were employed who want to do the whole farm at once.

Many farmers are already out applying fertiliser, but he was keen to add that soil temperature should be over 5°C for five continuous days at a depth of 10cm before applying fertiliser. If you are not sure, then get a thermometer which cost as little at £15.

Running a low fertiliser use farm?

As fertiliser prices remain strong, many are reviewing their application plans to ensure they are getting bang for their buck in the bag.

This week we spoke to Andrew Marchant, Clonhie Farm, near Penpont, Thornhill, about his strategic approach to maximising the benefit from artificial fertiliser.

“We have never used a massive amount of nitrogen on the farm,” said Andrew. “I haven’t had the money to buy it. Even when it was £220 per tonne, I felt an expensive purchase and now it is even more.

"I am not against bought in fertiliser and animal feed, but I want to targeted where I can get a return. Each year we would typically use around 25-tonnes of manufactured fertiliser.”

To optimise fertiliser use, he does not spread on any ground which has a lower pH than 6. For the last few years, Andrew has been reducing fertiliser and increasing spending on lime. He is applying 150 tonnes of lime a year on average to his 850-acre farm.

Lime last year cost Andrew around £27 per tonne delivered onto farm with an extra £6 per tonne to spread. He buys calcium lime as his magnesium levels are good on the farm and it comes by lorry from Annan, 30 miles to the south. He has, however, been adding in sulphur to any fertiliser he is buying.

To keep costs down and ensure a response from fertiliser, Andrew is reluctant to apply any fertiliser to older swards full of bent grass, fescue and weed grasses.

He added: “I really just identify the best areas on the farm and ramp up production on there. We would apply fertiliser on roughly half of the 350-ha of grass and would never spread more than 100kg of fertiliser per ha, aiming to apply little and often.

"This is enough inputs for our best fields to carry 50 Angus cross dairy stirks weighing 350kg grazing 25 acres broken up into paddocks.

"The older swards will receive no nitrogen but will have some clover stitched into the grass. These fields are able to carry five ewes with lambs to the acre. Again the fields will be broken into paddocks for rotational grazing."

Andrew stressed that this is not a flat simple farm with nice square fields, but his paddocks ranged in size and shape depending on the geography. He added that even in older swards, rotational grazing and giving the grasses time to rest over summer, had allowed more productive ryegrasses to compete better and there had been an increase in clover.

Andrew also gave this advice: “Don’t hammer the grass bare, it will damage output longer term.”

The farm doesn’t have a set plan for application of fertiliser over the growing season and he will respond to the growing conditions, targetting application to when the grass can best utilise the inputs.

Read more: Fertiliser supply dries up

Andrew had been switching application from early in spring to later in August, as he felt the grass was growing well without nitrogen at the start of the season. He had also switched to calcium ammonium nitrate (CAN) and away from ammonia phosphate as he thought it kinder to the soil and plants.

“I am a bit sceptical of getting out early with applications. I wasn’t happy with the response, as I felt the grass might grow anyway.

"We have been trying to push production to the back shoulder of the year and we also make sure our lambing parks have the ewes off them in January to build up cover for April.”

To compensate for rising feed costs, he is sowing 40 acres of red clover swards with an aim to increase quality of home-grown forage and to reduce future N requirement.

On the 850 acre farm Andrew runs 800 ewes, 25 suckler cows, 160 Aberdeen-Angus beef cross dairy stirks and 400 red deer.


Lime prices up £10/t

The cost of lime is rising off the back of increase haulage, fuel and labour costs according to Tom Hopkins, from Angus Lime Stores.

Lorries and quarry machinery had also been forced to switch to white diesel from the lower duty red diesel, which had added on 40ppl to his cost base. Roughly speaking, this is resulting in lime costing £38 per tonne to be delivered and spread on farm in Scotland.

Clearly, farmers who are more remote from lime production will incur extra cost, whilst those farmers next to quarries will see a discount, he pointed out.