How to improve grassland efficiency without more nitrogen

Most farms could find a 10-15% improvement in grassland efficiency without the need for more nitrogen.

Monitoring grass growth and matching it more efficiently to a farm’s grazing needs is the cheapest way to feed stock, says Lancashire beef and sheep producer Malcolm Sanderson.

He’s involved in a grass management trial that could bring significant benefits by not only by optimising the use of grazed grass, but also through savings made on bought-in feeds.

He runs 500 ewes – Mules and Texel-crosses – alongside 44 suckler cows at Lower Highfield Farm, Halton near Lancaster where he’s following the principles of grass management more akin to those of dairy farmers.

He will be using a plate meter this season to ensure he knows exactly how much grass he has on the farm at all times.

Grass monitoring

“Having the grass at precisely the right length to enable stock to use it more efficiently is what we’re aiming for,” says Mr Sanderson, who farms with his wife Judith.

“We’re going to be monitoring it closely and be ready to turn sheep out of a field if the grass is getting away from them.

“Sheep eating grass off a field is the cheapest possible way of feeding it; once you start cutting it and conserving it you are into more costs, so we want to make savings on the grass we have to conserve or the feeds we buy-in by making better use of the grazed grass.

Grassland improvements

The farm has already undertaken extensive grassland improvement and has been working closely with Helen Mathieu of British Seed Houses.

Re-seeding decisions have been influenced by soil analyses results and have seen some meadows re-seeded with long-term leys lasting up to seven years.

About 48ha of the farm has so far been re-seeded including some overseeding and there’s an ongoing policy of aeration, sward lifting and spring-time harrowing.

Trial results from last year looking at the farm’s potential to grow grass showed re-seeded fields yielded an average of 8.1t of DM/ha and the over-seeded fields yielded 6.3t of DM/ha.

That was a 52% and 27% improvement respectively compared with permanent pasture which was yielding 5.4t of DM/ha.

Farmax program

But this year the trial, which is being run by EBLEX, has been taken a stage further and will use the Farmax grassland programme. It will provide a monthly measurement of the kilos of dry matter produced by various fields so that the average “farm cover” – in terms of grass – can be closely monitored.

Based on the information provided by the programme, the Sandersons will be able to act quickly in terms of changes to stocking rates and be more in control of which fields stock should be grazing to maintain the most efficient sward height. In addition, the amount of silage and bought-in feeds will be recorded.

This trial is about measuring the grass growth and achieving a better understanding of what’s being grown on the farm at any particular time and how it can be used most efficiently, explains EBLEX beef and sheep scientist Liz Genever.

“We already have the data we gained from the work we did last year on a restricted acreage, but now we want to take it to all-farm level,” she says.

“There’s a lot of potential for farms like this to benefit from making the best possible use of the grass being grown, but we also have to be realistic.

“As well as the physical limitations of some farms there are environmental restrictions – which is the case for the Sandersons. So not everyone can grow 15t of grass a hectare, but we believe we can find a 10-15% improvement in efficiency in grass production on most farms without using more nitrogen.”

Fine-tuning

The trial, which is part of the Livestock North West programme, will look at fine-tuning the way stock are grazed so that they are in the fields they should be in when they can make the most efficient use of the grass available.

“We’ve had a situation at Highfield Farm where grass that’s too short is losing out on potential growth simply because there’s not enough leaf area available. It’s about achieving a balance and while there are benefits to short grass it mustn’t be too short.

“If we have a target cover of 1,400 in April, but the plate meter is showing us 1,300 how does Mr Sanderson react to that in terms of trying to achieve an increase and at what cost?

“That can be a situation caused by focusing on shutting up too much land for silage with the result that there isn’t enough grazed grass for stock to eat. It’s case of supply and demand but there can be too much demand and inadequate supply.

“The solution? Well in that situation you can either reduce demand by spreading stock over more land or supplementary feeding to get over the shortage gap,” explains Dr Genever.

But while getting more from grassland has never been more important as a means of off-setting the high cost of bought-in feeds, Dr Genever says the stress grassland has been under for the last eight months cannot be ignored in the coming season as we try and use it more efficiently.

The Farmax programme, which was developed in New Zealand, will calculate grass growth this year based on monthly plate meter readings.

Figures from plate meter readings taken in August last year showed the farm was running at slightly below target with the production of DM/ha ranging from 1,228kg to 2,068kg of DM/ha.

Dr Genever says: “An animal’s demand for dry matter intake is 1.5-3% of its bodyweight. That will depend on whether it’s a growing animal, suckling or not and pregnant or not. So an in-lamb ewe in mid-pregnancy weighing 70kg would require a daily intake of 1.4kg dry matter – that’s about 2% of her bodyweight.”

Tackling how best to adjust sheep and suckler cow management strategies on the farm to make the optimum use of grass growth will be the focus for the coming season.

Lower Highfield Farm sells most of its lambs finished by late October and calves are sold as 12-month-old stores.

Says Mr Sanderson: “Trying to manage the grazing so we have grass as soon as we possibly can to turn ewes and lambs on to in mid-March will be one of the main targets.

“But just because you measure grass doesn’t mean to say you’ll have more of it or have it any earlier, but at least it gives you more information to work with.

“The weather is obviously going to play a big part in what we can do this year, but if we can manage the grazing better, keep it at the right length and move stock around the farm as the grass growth demands, we must be able to get more from it and try and reduce what we have to buy-in. We want to achieve more control over the grass and how we make use of it.”

Grass facts

• Re-seeded fields yielded an average of 8.1t DM/ha (52% improvement)
• Over-seeded fields yielded 6.3t DM/ha (27% improvement)
• Animal’s demand for dry matter intake is 1.5-3% of its bodyweight
• Farmax programme puts farmers in control of which fields should be grazed to maintain most efficient sward height

Grass grazed too short could lose out on potential growth simply because there’s not enough leaf area available.