Planning ahead for this year’s forage stocks and weed control were some of the topics up for discussion at this years Grassland UK event held at Shepton Mallet, Somerset. Peter Hollinshead and Jonathan Wheeler report.
Dairy producers face the prospect of a serious shortfall of forage this coming winter unless they seek ways to mitigate the impending disaster.
According to Graham Ragg, senior agronomist with Mole Valley Farmers, the first thing to do is
increase the area set aside for second cut by upping the stocking density on the grazing ground.
He said: “On grazed ground, we recommend two units N/day, so in a paddock system on a 25-day cycle, that would be 50 units between each grazing.
“What we are suggesting is producers could lift that to three units/day to allow for the higher stocking rate.”
His next recommendation was to ensure fertiliser is put on as soon as the silage grass is off so as to maximise its effect.
“If you get it on straightaway you get extra yield at no extra cost. If you leave it a week, you will see a 14 per cent reduction, which would be 1t/acre less freshweight on a 7t cut,” he said.
“If you are cutting 100 acres, that is 100t extra silage with early application.
“And if you use a sulphur fertiliser you will see a 30 per cent boost on your second cut, so instead of being 7t/acre, it could be 9t/acre. This more than pays for the cost of the sulphur.”
Two contributory elements which had commonly shown up among the 5,000 soil samples MVF does every year, were the need to correct potash levels and soil acidity.
He said 10units/acre of potash were taken off with every tonne of freshweight grass, and on a three-cut system producing 20t freshweight would mean 200 units being removed over the season.
“That is why we recommend a 22:4:14 10SO3 fertiliser at 430kg/ha (3.5cwt/acre) after first cut to help restore potash levels,” he said.
“In addition, our analyses are showing the lime status is too low. Typically grassland pH is showing 5.5 when it should be nearer 6.
“That is one of the biggest things that needs to be done before you get a meaningful response to any fertiliser. If the pH is 5.5 instead of 6, you are losing 35 per cent of the nutrients you are putting on.”
Silage makers could be hit with a double whammy of weed incursion this season as a result of an inability to tackle them earlier in the season and a surplus of residual N left from a lighter first cut stimulating rapid growth.
Andy Bailey, from Corteva Agriscience, said: “The season is two to three weeks later than usual and as the temperatures come up, weed growth has accelerated.”
He said where producers had been unable to spray before first cut it was not too late to tackle a problem like docks between cuts.
“But you have to leave them two weeks to get enough growth and a further two to three weeks for the herbicide to translocate,” he added.
In addition, he said creeping thistles are also prevalent following the wet summer last season, and buttercups were common although the best time to control these was before the plant flowered.
But one of the biggest threats was from a whole new generation of dock seedlings which were springing up because of open patches of poached ground following the very wet autumn and spring.
“There are a lot of young plants but these are relatively easy to control and the opportunity is here now between cuts,” he explained.
THE company warned that certification is needed even for knapsack spraying and this is
the last year of ‘grandfather rights’.
People born before the end of 1964 need to register before December 31 this year to enter for the quicker and cheaper route to qualification, as otherwise they would have to take the full course and test which could take up to two days.
Corteva’s livestock market manager Robin Bentley said: “Almost all farmers will want to use a knapsack to tidy up around the farm with glyphosate or a spot treatment on docks, thistles or nettles in grass fields.
“To apply these professional-use products farmers must hold an appropriate certificate.”
The shorter route is only applicable to those using such products on land they own or occupy, not on other people’s land.
The most valuable tool on a livestock farm could be a spade, suggested Mark Tripney, an independent soils consultant.
The depth at which compaction may be present changes according to how it is caused and farmers need to detect that before they attempt to remedy it, hence the importance of a spade.
If it is caused by surface trampling, then it will be shallow and can be repaired with an aerator – a machine he suggests is very under-utilised.
But deeper set problems resulting from machinery movements or cultivations may require sub-soiling if the soil’s structure and activity is to be restored.
“It is common to find a significant thatch layer in grassland, and the fact so much of the fertiliser is surface-applied means grass roots often don’t go down any distance,” he told the audience at a seminar on soil structure.
“If you were planning to work 12 inches deep but find out you only need to go eight deep, then you will save a lot of diesel and wearing metal.”
Including grass leys in rotations could help control black-grass, solving one of the arable sector’s most persistent and expensive problems.
And choosing deep rooting varieties could also help, said Mark Simes, of DLF Seeds.
He said grass leys could help smother the weed, while the grazing or frequent cutting of leys would ensure it never has the opportunity to set seed.
But the first forage cut might need to be made early in the year, he said – showing a photograph of a black-grass plant with set seed taken on April 29.
If farmers sow with a grass like a deep rooted festulolium it could benefit the soil in several ways.
He said: “The deep rooting varieties can help break up heavier soil types and restore their structure. On a light, sandy types those same roots would help hold the soil together and stabilise it.”