Focus on sward heights this autumn to improve grass quality
Farming Connect - 2015-09-10
Sheep farmers can potentially double the percentage of productive grasses in their pastures by making simple grazing and soil management changes this autumn.
Grassland specialist Chris Duller, who has been advising farmers in Wales at a series of Farming Connect grassland and soil clinics, says sheep farmers need to avoid putting too much emphasis on building covers to fatten lambs and flush ewes, leading to wasted grass and poor sward quality and condition.
Careful attention to sward heights this autumn will improve both animal performance and sward quality. Once a sward gets above 12cm, particularly in a mixed sward with weed grasses as well as ryegrass, quality can be lost as well as sward density.
“Flush ewes on the fields that need attention, then at some stage over the winter, give those poorer fields a break. Shut some gates and keep sheep out,” advises Mr Duller. “Ryegrass and clover need a chance to root and to grow so farmers need to make sure that those fields that are a bit low in ryegrass and clover don’t get absolutely hammered all winter. Resting a couple of fields obviously puts more stocking pressures elsewhere and farmers may have to feed more – but the net result will be longer lasting leys, less reseeding costs and better quality grass in the spring.’’
Management changes can allow leys with a ryegrass content of just 35% to
rejuvenate, he suggests. “With just a little bit of attention, not dramatic
changes, ryegrass levels can build up to 60%.
“Ryegrass is more competitive and aggressive than weeds, give it the right conditions and it will regenerate, tiller and fill gaps.’’
If autumn sunshine can get to the base of the ryegrass plant then it is more likely to tiller – so ideally nothing taller than 12cm, Mr Duller recommends. “If you can maintain a good leaf area through autumn and early winter the ryegrass will be able to build and store some sugars to take it through until spring, so preferably nothing below 4cm.
“I don’t expect every single field to be managed to ‘ideal’ sward heights, but if you just try and achieve these targets with a couple of fields that are maybe a bit open and short of ryegrass and clover it will pay dividends next year.’’
Mr Duller recommends every field should be given an annual MOT. “Walk the fields and look at what percentage of weeds there are, soil test, look at the condition of the soil. We hear about ram MOTs and farmers MOT their farm vehicles but they don’t MOT their fields. When you are walking the fields, take a spade with you and dig a hole, this is an ideal way of assessing soil structure and any underlying issues like compaction. Good soil biology will release more nutrients and clover will fix more nitrogen.’’
Mr Duller says there are signs that farmers can recognise to help spot the first signs of when a field is starting to go backwards and give support to that field at that point.
“In poorer fields at this time of year you’ll start to see a lot of annual meadow grass and creeping bent being pulled out by the sheep, leaving open and patchy swards,’’ he says.
“Where soil conditions aren’t right, either nutrients or soil structure, then weeds like creeping buttercup, daisies and sheep sorrel are likely to be evident. Also you’re likely to see a build-up of dead material and thatch in the sward base along with moss.
“As soils wet up and temperatures drop you’ll see signs of stress on ryegrass where soil conditions aren’t right – red tinge to the leaves and more disease levels which is evident through yellow leaf tips and dead leaf. Soil test and check soil structure to find out why the ryegrass isn’t happy.’’
At 148-acre Tydu Farm, near Nelson, Caerphilly, Lyn and Adam Bowen are in a position to increase their flock numbers since correcting soil pH levels and grazing leys effectively.
The father and son attended a Farming Connect soil and grassland clinic and are putting that advice into practice to rejuvenate fields that had become overrun with weed grasses, including Yorkshire fog and creeping bent, because the farm had been under-grazed for three years. The pH levels were low in most fields.
“The fields looked like they were productive but they had no grazing value. We were going into the autumn with a thick thatch on the ground layer which had been created by under-grazing so the sunlight wasn’t getting to the base of the plant,’’ says Lyn.
A grass spiker had been used on some of the fields but there was an underlying problem - the ground was lacking lime and the leys were tired. Soil tests established that pH levels ranged from 5.2 to 5.7.
To correct this, the Bowens have applied lime to 40 acres over the last 12 months, at two tonnes/ acre, an investment of £2,000. They will spend a further £4,000 liming another 80 acres over the next 12 months.
Rectifying the soil pH along with grazing leys tighter in the summer means the Bowens can now carry more sheep and expand production of haylage for selling. They have retained yearling replacements and are currently running 200 Nelson-type Welsh Mountain ewes and 100 ewe lambs. They plan to increase numbers further to 400 next year.
“The advice we got through Farming Connect really focused our minds on what we needed to get the farm working for us again,’’ says Lyn.
Top tips for managing sheep grazing leys this autumn:
- Identify poorer fields, those with a low ryegrass percentage – avoid putting low condition ewes here.
- Don’t waste grass and quality by grazing long swards.
- Keep animals moving – give grass a chance to recover and build sugar reserves.
- Don’t put stress on struggling fields in late autumn – give ryegrass and clover an opportunity to build.
Photos for this release:
Lyn and Adam Bowen canincrease their flock numbers after correcting soil pH levels and grazing leys.