Dealing with dry summers

After experiencing a dry summer with low rainfall Chris Elkington, from our lamb strategic farm in Lincolnshire, updates us on what's been happening over recent months.

Since the last meeting in June, the farm has experienced a dry summer with low rainfall. The plan to rotationally graze on 2-day moves, with ewes following lambs, had to change.

As grass burnt off, lambs were weaned early at 12 weeks, although Chris says this could have been earlier. Lambs were kept on grazing, 2-day moves, and offered silage. Offering silage and small amounts of barley and oats helped reduce the pressure on the grazing.

Ewes from both the indoor and outdoor lambing flocks were moved from grass onto sacrifice fields by the end of July and fed baled silage (6, 300 kg bales every 2–3 days for 400 ewes). Body condition score (BCS) of ewes was assessed before and after feeding silage, with ewes now on BCS of 3–3.5, showing that the silage did a good job of maintaining ewes’ condition.

After a month of feeding silage, the farm received 33 ml of rain. Chris drilled 70 acres of turnips, forage rape and oats for winter feed. The ewes had almost no worm burden through the dry summer, although two weeks after rain, the worm burden increased significantly.

The week before the event, the ewes were moved off farm onto a field of volunteer beans to keep grass for lambs.

Herbal ley farm walk – Chris Elkington and Liz Genever

The farm has 15 acres of permanent pasture, new grass leys, ryegrass and white clover leys, and herbal leys (some GS4 leys and some white and red clover leys).

The chicory and plantain perform well on farm, although the legumes (clover) have not performed as well. Previously, much of the farm was ryegrass and white clover swards which were rotationally grazed.

Sward establishment

Two herbal ley swards were established this year. The GS4 herbal ley in Bottom field was established in May and started to be grazed at the end of summer. The GS4 herbal ley in Carrs field was established end of August. Carrs field had a low P index, so Chris and Liz are conducting a trial in the field to understand how to feed the mixtures.

Carrs field ley was established following a six-year-old grass ley by: disced (twice), power-harrowed (twice), flat-rolled, broadcast seed (two directions at 14 kg/acre), Cambridge rolled (twice). The previous sward had not been sprayed off.

Bottom field was established in May as a four-year ley. It is currently being block-grazed by lambs, but Chris is considering strip-grazing the ley instead to use the stocking rate to increase the grazing pressure. This is the leys first graze since it was established, and lambs grazing the herbal ley are growing at 190 g/day.

Managing herbal leys vs ryegrass swards

“Grazing management is not about perfection but knowing how to get it back right to where you want it”, said Liz Genever.

The farm historically had an issue with the growth of perennial ryegrass, which could be down to poor establishment due to low P availability. Leatherjackets are an issue also. The farm is a low rainfall, dry area, so Chris wouldn’t want the whole farm as ryegrass. However, ryegrass still has a place on the farm, and Chris is aiming for diversity across the farm. Ryegrass is the most sensitive to lack of rain, however, it is also the most responsive to bounce back after some rain and has a very good nitrogen response. Going forward, Chris could think about using different grass species other than perennial ryegrass, which could give better winter cover and provide a bit more diversity on farm.

Herbal leys are a learning curve and need to be managed differently to grass and clover swards. The leys cannot be grazed too wet or too frequently; they need a good rest period, ideally 40 days minimum. In winter, swards can be grazed gently, but stock will need to be moved daily to not kill the sward. The herbs in the herbal ley are not as resilient as ryegrass due to the crown and tap root. Herbal leys need high sulphur and phosphorus, and any Nitrogen should be used strategically. The taste of the sward will depend on mineral availability. There is currently very limited UK research on herbal ley species performance.

The GS4 herbal ley option also requires additional management. The sward needs to be rested between May and July to allow flowering for pollinators, which means the rest of the year the sward must be controlled. The species in the ley all grow in different ways and speeds, so it can be difficult to know which species to manage within the ley. For example, grass tends to dominate in autumn-established herbal leys.  

For the destruction of a herbal ley; graze hard and disturb the thatch, spray off, or if there is grass in the sward, let the grass dominate. You can use lime to reduce the thatch or nitrogen in the re-seed to counteract the thatch (and the effect the thatch will have on reducing establishment).  

Mixed grazing of cattle and sheep

Herbal leys are perfect for mixed sheep and beef systems. The benefits of mixed grazing systems are the benefit of worm burden, grazing management, and to prevent the need for topping. There is a 30 g/day liveweight gain advantage in lambs just from having cattle in the rotation. Management of herbal leys can be less challenging if grazing with cattle and sheep, as cattle are much better at grazing tall herbal leys than sheep. The challenge when having cattle within a sheep system is bovine TB and cattle handling.

Key points

Chris had a few approaches to deal with the dry summer conditions, including:

• Weaning lambs earlier
• Offering lambs and ewes alternative forage to keep grazing available
• Offering a range of crops and forage across the farm

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