Re-seeding grass leys is promoted widely as the key to greater productivity but what are the options for those who want to make the most of older grassland leys? Chloe Palmer finds out more.
Permanent grassland forms a significant area on many livestock farms yet methods of maximising production from it are rarely discussed. Many farmers choose to retain older swards believing it is cost effective to do so or because their Stewardship Scheme precludes re-seeding.
Production from grass swards is not always just about the species mix, according to George Dodds, a farm environment consultant from Northumberland. He believes farmers should not seek to blame poor grass production on sward composition alone.
Issues such as poor drainage, acidity, compaction and under-grazing can all contribute to reduced production as well as loss of grass vigour.
He says: “Often, poor drainage will be the main reason for poor yields, and it is vital to put this right before considering a re-seed. I have seen many permanent grassland fields where productivity increases dramatically once drainage is fixed.”
He also warns under-grazing and a lack of management can lead to the proliferation of less palatable and tussocky species, such as tufted hair-grass and rushes.
Mr Dodds refers to old rig and furrow grassland which was created to improve drainage centuries ago. “The worst examples of grassland improvement can be ploughed up ridge and furrow grassland. Often they were created on inherently heavy soils so once it is ploughed out, the soils slump and lie wet.
“Farmers in Stewardship agreements can apply for a derogation to apply lime if soil samples show a low pH. Trials have shown the correct quantities of lime can increase the abundance of flowering species in traditional hay meadows.
Professor McCracken describes permanent grassland as a ‘significant feature within the ruminant livestock systems’ in Scotland, both as in-bye grassland and rough grazing.
He says permanent grassland is an important resource both for grazing and conserved forage and if managed quite intensively, it can be productive.
“For many farmers in more marginal locations, the benefits of re-seeding are not always clear and the costs are higher if contractors have to be bought-in. Finding the right grass seed mix is challenging because most of the species are more suited to lowland situations with lower rainfall amounts.
“However, in many upland areas of the country, rainfall amounts can be in excess of 200 centimetres, meaning reseeding is rarely practical. Where reseeding is undertaken, many of the native species will recolonise quickly, so farmers cannot recoup the costs incurred.”
“I have seen fields in Stewardship Schemes where floristic diversity is retained but grass growth is strong. In these cases, lime has been applied and grassland has received regular applications of farmyard manure.”
Mr Dodds points to the higher input costs associated with newly reseeded grasslands if they are to meet their full potential.
“If fields are reseeded regularly, higher fertiliser inputs will be required to see the benefit of the investment, so costs are effectively ramping up year on year. For some farmers, looking to a lower-input, lower-output system might be the answer.”
Even where higher grass yields are sought, where older swards continue to perform well, there may be little justification for reseeding according to Alan Hopkins of GES Consulting. He disputes the view newer leys will always perform better than permanent swards. “Most permanent pasture swards give similar yields to rye-grass if they are grown under the same conditions. This has been shown
consistently in experiments and farm trials.
“In practice, sown swards tend to receive more fertiliser, or the pH, phosphate and potassium status is better maintained so they produce more.”
Mr Hopkins says it is important to consider the value of white clover, and suggests adding clover to swards can be beneficial.
“Cattle and sheep prefer clover to grass and, given a free choice, will select a mixed diet which has more than half clover. If the permanent pasture has little or no clover, a reseed with a worthwhile clover content will be more productive and of higher quality.”
Mr Hopkins believes permanent grassland has an important role to play on many farms as it can be more resilient to poaching, due to the dense mat of vegetation. He says: “Older swards are often the last to be grazed in autumn and the first in spring. Sheep might graze them after lambing and cattle may be turned out on them during the day in the transition between winter housing and full turnout.
“Permanent pasture contains species such as cocksfoot, tall fescue and clovers with deep roots which can access moisture during summer drought. Conversely, there are the damp meadows with grasses like meadow foxtail which are vigorous in spring, quite productive and may be too difficult to reseed.”
Selling the story of grass-fed livestock is one way of adding value to produce reared on permanent grassland, Mr Hopkins says.
“The opportunity to use the attributes of diverse pastures to add value to the produce is emerging as a potential selling point. Many producers are seeking a better price for meat reared in special environments, for example salt-marsh or heather lamb.”
Achieving impressive milk from forage figures is one of the principle reasons why Brook House Farm has retained top position in the MilkMinder league table of farmers.
Making and feeding the highest quality silage contributes to the yearly average figure of 5,120 litres from forage, according to Adrian Smith.
“I aim to make silage which analyses at a minimum of 17-18 per cent protein. To achieve this, it is vital the grass we grow produces quantities of sugars as soon as the sun begins to shine.”
Mr Smith acknowledges the remarkable advances in breeding new grass varieties. Nevertheless, older leys are retained where volumes, quality and palatability of silage made from these fields exceeds the high standards required by Mr Smith.
“We monitor every aspect of silage production. I map the silage in my clamp so I know exactly which field it came from and when it was made. By testing silage made from different fields at the same time, I can identify which swards are no longer performing.”
Mr Smith says one group of fields which was reseeded just two years ago has proved disappointing. “Although we are getting the anticipated volume of silage from these fields, it is not analysing as well as silage made from other leys which are up to eight years old.
“Excellent silage is the result of many factors and it is attention to detail which makes the difference. We have excellent contractors and they are used to me watching every aspect of the process.”
Mr Smith follows the contractors on his quad bike, inspecting every field so he can prescribe whether it will be necessary to ted the grass in one field, or so he can give the instruction to rake up a field at exactly the right moment.
Fields close to the farm are paddock grazed and tend to be reseeded less frequently than silage ground further away. Accurately monitoring the performance of grazed grass is not easy, but Mr Smith takes the time to assess whether fields are producing grass of sufficient quality and quantity.
He says: “I watch cows grazing and look out for the signals to see if they are eating sufficient quantities and I will also look at the milk tickets. We will spread rock salt on the grazing fields to sweeten the grass and aid palatability.”
Where older grazed swards are in need of reconditioning, Mr Smith will take them out of the grazing rotation for two to three weeks.
“We let grass grow on and then make big bale haylage from it, which we feed to youngstock. Even for this coarser crop we will usually record protein values of 15-17 percent.”
The under-performing leys are also used for making hay which is fed to calves from three days old. He says: “We begin feeding hay to calves to develop the rumen. At four to six months old, we will switch them to haylage. All forage fed to the calves, youngstock and cows is changed at least every other day to maintain intakes and quality.”
Before choosing to undertake any management of a grassland field, Mr Smith will always examine it first carefully. “I soil sample the entire farm every other year and I will dig three or four holes in each field every year to look for signs of compaction in the subsoil and topsoil.
“I make sure the subsoil is right before doing anything to the topsoil. I will aerate or roll fields but only if they need it.”
Mr Smith believes there is no magic fix when managing grassland but rather it is better to go back to basics. “The most important tools on my farm are my time, the spade and the quad bike. I take the time to drive around each field and monitor what is going on because I believe we can always do things better.”