Where new clover swards were established in the last year, these plants will now be now be coming in to their own, in terms of nitrogen fixing properties, provided they are properly managed.
But clover offers more than just free nitrogen. The plant has higher crude protein levels than ryegrass, usually contains more trace elements, has good drought tolerance and offers high levels of digestible forage for grazing animals.
However, it does have its downsides – clover only performs to its potential on well-managed and fertile soils. It doesn’t tolerate wet conditions or poaching, and there is a risk of bloat in certain situations.
As clover plants usually perform better in the second half of the year, outlined are 10 tips to get the most from clover over the remainder of the grazing season.
Clover performs best when soil pH is in the region of 6.3 to 6.5. At the very least, soils should be above pH 6.
If pH is below these levels, then lime will be required. Ground limestone gives a longer term fix, but it can take four to six months to properly correct soil pH. Therefore, use a granulated product for an instant fix on acidic soils this summer. Apply ground lime in the autumn, setting swards up for next year.
Phosphorous (P) and potash (K) levels should have been addressed before sowing clover. Soils at index 2, or above, will give better establishment, so keep this in mind if reseeding. On established swards, livestock manures and slurry can be used to top up P and K levels over the summer, provided conditions are right for such applications.
With slurry, aim for a maximum of 1,500 gallons/acre with a high water content. This will reduce the risk of tetany should lactating cows graze the sward in the next rotation.
The availability of nitrogen in slurry is much lower with summer applications than in spring, but P and K levels are similar, making it more applicable time wise for spreading on clover swards.
Clover is normally a slow growing plant in spring, but comes in to its own by summer. Therefore, applying nitrogen to swards in March, April and early May is fine. But by June, cut back or eliminate nitrogen fertiliser applications on clover swards.
The plant will only use the chemical form of nitrogen for growth, rather than fixing soil nitrogen for its own use and accompanying grasses.
Check the root nodules for N fixing activity
Clover has nodules on its roots called rhizobia. It is these nodules that fix nitrogen.
To check if the plant is fixing nitrogen, dig a few soil cores and examine the roots.
If the nodules have a red or pink colour, they are fixing nitrogen.
Allow the plant to flower
Clover swards, and in particular, red clover should be allowed to flower at least once during the season. This is important where clover is used in multi-cut silage systems.
By letting the plant flower, it will increase the energy reserves in its roots and thereby helps with long term persistency.
Rotational grazing to rest the sward
White clover performs best in a rotational paddock setup, where swards are grazed tight in a three- to four-day period, then rested for three weeks.
As white clover tillers out with its runners (stolons) spreading across the ground, it doesn’t thrive when grazing swards are consistently carrying heavy covers.
Heavy covers will shade out the white clover and deplete the energy in the plants roots.
Aim for short, sharp grazing periods with swards grazed down to 4cm, followed by a 21-day rest period.
As clover is easily digested by cattle, bloat is always a possibility. But there are ways to avoid this problem.
Introduce cattle to clover swards gradually, as this will stop animals gorging on the plant.
Strip grazing will control intakes at the start.
Once cattle settle on to clover swards, they can be given unrestricted access.
On clover/ryegrass swards, once ryegrass heads out there will be more fibre in the grazing animal’s diet.
Fibre will slow down cattle’s digestion and intakes, thereby lowering the risk of bloat. There are also anti-bloating oils that can be added to water, as can most cooking oils.
Never turn cattle in a fasted state into a fresh field of clover, especially in wet conditions as these factors combined greatly increase the risk of bloat.
Keep this in mind if cattle are being gathered for handling. Animals should be returned to grass as soon as possible.
Red clover grown for silage needs careful management. Set the mower to cut around 8cm in height. Cutting below this height increases the risk of damaging the plant’s crown, shortening the lifetime persistency of the sward.
Red clover is an extremely brittle plant. When mowing, open the boards on the mower to spread the swathe as wide as possible.
Do not spread out the sward with a tedder as this will increase plant losses.
Leave the sward to wilt for at least 36 hours, then ideally bale.
Red clover silage needs a dry matter above 30% to encourage fermentation, as the plant contains a lot of residual nitrogen.
Increasing clover content in swards
If there are plans to increase clover in existing swards, or through reseeding, choose a variety that suits the purpose of the sward.
Small leaf varieties are lower yielding, but have a greater stolon density, making them ideal for grazing sheep.
Medium- and large-leaf varieties are better suited to cattle grazing. Large varieties also suit silage systems. White clovers are better suited to grazing, with red clovers more suited to silage swards.
White clover seeds are extremely small, so drill at a rate of 1.5kg/acre between 5mm to 10mm deep.
Red clover has bigger seeds, so drill at 3kg/acre to a maximum depth of 10mm.
Control weeds before reseeding as “clover safe” spray options extremely limited. When reseeding after ploughing, roll the seed bed before and after drilling. If stitching in clover, choose an open sward and remove as much trash as possible beforehand. Apply lime as decaying grass can be acidic and hinder germination.
If red clover swards will be grazed at some point this summer, target these paddocks with growing cattle, cows and weaned lambs.
Be careful not to damage the plant.
A grazing residual of 8cm is crucial. Move cattle on to the next allocation every 12 to 24 hours.
Back fence grazed areas to protect the plant and encourage regrowth.
Red clover contains oestrogens that can have a negative impact on ewe fertility, but do not effect suckler cows.
Therefore, move breeding ewes off red clover swards at least one month before they go to the ram to avoid fertility issues.
Read more
Managing time to move up margins in Mullingar
‘Rapid increase’ needed in use of newer fertilisers to slash emissions - CCAC
Where new clover swards were established in the last year, these plants will now be now be coming in to their own, in terms of nitrogen fixing properties, provided they are properly managed.
But clover offers more than just free nitrogen. The plant has higher crude protein levels than ryegrass, usually contains more trace elements, has good drought tolerance and offers high levels of digestible forage for grazing animals.
However, it does have its downsides – clover only performs to its potential on well-managed and fertile soils. It doesn’t tolerate wet conditions or poaching, and there is a risk of bloat in certain situations.
As clover plants usually perform better in the second half of the year, outlined are 10 tips to get the most from clover over the remainder of the grazing season.
Clover performs best when soil pH is in the region of 6.3 to 6.5. At the very least, soils should be above pH 6.
If pH is below these levels, then lime will be required. Ground limestone gives a longer term fix, but it can take four to six months to properly correct soil pH. Therefore, use a granulated product for an instant fix on acidic soils this summer. Apply ground lime in the autumn, setting swards up for next year.
Phosphorous (P) and potash (K) levels should have been addressed before sowing clover. Soils at index 2, or above, will give better establishment, so keep this in mind if reseeding. On established swards, livestock manures and slurry can be used to top up P and K levels over the summer, provided conditions are right for such applications.
With slurry, aim for a maximum of 1,500 gallons/acre with a high water content. This will reduce the risk of tetany should lactating cows graze the sward in the next rotation.
The availability of nitrogen in slurry is much lower with summer applications than in spring, but P and K levels are similar, making it more applicable time wise for spreading on clover swards.
Clover is normally a slow growing plant in spring, but comes in to its own by summer. Therefore, applying nitrogen to swards in March, April and early May is fine. But by June, cut back or eliminate nitrogen fertiliser applications on clover swards.
The plant will only use the chemical form of nitrogen for growth, rather than fixing soil nitrogen for its own use and accompanying grasses.
Check the root nodules for N fixing activity
Clover has nodules on its roots called rhizobia. It is these nodules that fix nitrogen.
To check if the plant is fixing nitrogen, dig a few soil cores and examine the roots.
If the nodules have a red or pink colour, they are fixing nitrogen.
Allow the plant to flower
Clover swards, and in particular, red clover should be allowed to flower at least once during the season. This is important where clover is used in multi-cut silage systems.
By letting the plant flower, it will increase the energy reserves in its roots and thereby helps with long term persistency.
Rotational grazing to rest the sward
White clover performs best in a rotational paddock setup, where swards are grazed tight in a three- to four-day period, then rested for three weeks.
As white clover tillers out with its runners (stolons) spreading across the ground, it doesn’t thrive when grazing swards are consistently carrying heavy covers.
Heavy covers will shade out the white clover and deplete the energy in the plants roots.
Aim for short, sharp grazing periods with swards grazed down to 4cm, followed by a 21-day rest period.
As clover is easily digested by cattle, bloat is always a possibility. But there are ways to avoid this problem.
Introduce cattle to clover swards gradually, as this will stop animals gorging on the plant.
Strip grazing will control intakes at the start.
Once cattle settle on to clover swards, they can be given unrestricted access.
On clover/ryegrass swards, once ryegrass heads out there will be more fibre in the grazing animal’s diet.
Fibre will slow down cattle’s digestion and intakes, thereby lowering the risk of bloat. There are also anti-bloating oils that can be added to water, as can most cooking oils.
Never turn cattle in a fasted state into a fresh field of clover, especially in wet conditions as these factors combined greatly increase the risk of bloat.
Keep this in mind if cattle are being gathered for handling. Animals should be returned to grass as soon as possible.
Red clover grown for silage needs careful management. Set the mower to cut around 8cm in height. Cutting below this height increases the risk of damaging the plant’s crown, shortening the lifetime persistency of the sward.
Red clover is an extremely brittle plant. When mowing, open the boards on the mower to spread the swathe as wide as possible.
Do not spread out the sward with a tedder as this will increase plant losses.
Leave the sward to wilt for at least 36 hours, then ideally bale.
Red clover silage needs a dry matter above 30% to encourage fermentation, as the plant contains a lot of residual nitrogen.
Increasing clover content in swards
If there are plans to increase clover in existing swards, or through reseeding, choose a variety that suits the purpose of the sward.
Small leaf varieties are lower yielding, but have a greater stolon density, making them ideal for grazing sheep.
Medium- and large-leaf varieties are better suited to cattle grazing. Large varieties also suit silage systems. White clovers are better suited to grazing, with red clovers more suited to silage swards.
White clover seeds are extremely small, so drill at a rate of 1.5kg/acre between 5mm to 10mm deep.
Red clover has bigger seeds, so drill at 3kg/acre to a maximum depth of 10mm.
Control weeds before reseeding as “clover safe” spray options extremely limited. When reseeding after ploughing, roll the seed bed before and after drilling. If stitching in clover, choose an open sward and remove as much trash as possible beforehand. Apply lime as decaying grass can be acidic and hinder germination.
If red clover swards will be grazed at some point this summer, target these paddocks with growing cattle, cows and weaned lambs.
Be careful not to damage the plant.
A grazing residual of 8cm is crucial. Move cattle on to the next allocation every 12 to 24 hours.
Back fence grazed areas to protect the plant and encourage regrowth.
Red clover contains oestrogens that can have a negative impact on ewe fertility, but do not effect suckler cows.
Therefore, move breeding ewes off red clover swards at least one month before they go to the ram to avoid fertility issues.
Read more
Managing time to move up margins in Mullingar
‘Rapid increase’ needed in use of newer fertilisers to slash emissions - CCAC
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