Grazing more sheep with less fertiliser

The switch from a set stocking system to paddock grazing has meant Clement Lynch can graze twice the number of sheep with half the amount of fertiliser.

At a recent CAFRE event on the farm in Park, Co Derry, visitors were shown a block of land beside the farmyard which is grazing 94 ewes and 184 lambs.

“There is slightly over 13 acres here and it is split into seven paddocks of a fairly equal size. It is two fields. One is divided into three and the other is in four paddocks,” Clement said.

“Further over, there are nine paddocks grazing a similar number of sheep. There is sixteen acres there. It is slightly wetter and heavier ground,” he added.

The 13-acre block closest to the farmyard used to graze 50 ewes and 100 lambs when it was set stocked, so the stocking rate has almost doubled since the fields have been sub divided.

Different types of fencing were used to split the fields. This includes metal sheep wire with wooden posts, sheep wire with galvanised steel posts, and four strands of electric fencing polywire with plastic posts.

Set stocking is a system of grazing where livestock graze the same area of land constantly. This system requires less labour input and management decisions as stock do not have to be moved.

However, set stocking leads to significantly lower grass yields as fresh regrowth is continuously nipped off before the grass plant gets a chance to properly grow.

It also leads to poorer sward quality, as livestock selectively graze off leafy parts of the grass plant which allows it to shoot and produce seed heads.

Paddocks

With fields sub-divided into paddocks on the Lynch farm, the general rule of thumb is that each paddock is grazed for three days then is rested for three weeks.

The aim is to put sheep into grass covers of 2,800kgDM/ha (8cm in height) and graze the sward down to 1,600-1,700kgDM/ha (4.5-5cm).

The paddock system gives the grass plant an opportunity to grow back, and the short, intensive grazing helps clean off stemmy material that is present in the sward too.

Clement has a strong focus on keeping quality grass in front of stock, as only one paddock on the farm has not been topped so far this year.

“When the sheep come out of a paddock, I run the topper over it. Some people might think I am only burning diesel because there will be very little grass on it, but it means any stalky bits are cleaned off,” he said.

Fertiliser usage has declined since the approach to grazing changed on the Lynch farm. Clement estimates that he is spreading at least 40% less fertiliser on the ground that is now sub-divided into paddocks.

“This year, I didn’t get my first fertiliser on till the middle of April, which is six weeks later than usual. I went on again on 11 June with half a bag an acre of protected urea compound fertiliser (29-0-14),” he said.

Grass measuring

Throughout the growing season, grass is measured on the farm each week with a plate meter and the grassland management software package AgriNet is used.

“It’s been cold and growth is lower than normal but I’m okay for grass at the minute. I measured today and I have 21 days of grass ahead of myself,” he said.

Clement explained that weekly grass measuring and budgeting allows steps to be taken early on to address shortages and surpluses of grass.

For example, he usually only spreads fertiliser on grazing ground during the summer months when growth rates fall below 50kgDM/ha.

Earlier this year when grass was growing well, Blackface ewes and their lambs were taken off hill ground to graze surplus grass in the paddocks near the yard.

Grass measuring also allows poorer performing paddocks to be identified and earmarked for reseeding. Last year, the paddocks on the Lynch farm averaged 9tDM/ha, with the best performing paddock growing 13tDM/ha.

White clover in sward after min till reseed

White clover has been incorporated into some grazing swards in recent years to help reduce chemical fertiliser usage.

Visitors were shown a paddock that was reseeded last August with a seed mix that contained clover at a rate of 2kg per acre.

The old sward was sprayed with glyphosate before getting a pass with a rotavator then two runs with heavy disks.

Clement said he opted for a min-till reseed because it can be established quickly during a short period of dry weather, and it requires a lot less work with lifting stones compared to a full plough reseed.

Some docks are present in the new sward and the plan is to spray the field next spring with a clover safe spray.

Clover only grows when soil temperatures are above 8°C, so the prolonged cold weather this summer has meant the white clover in the new reseed was slow to appear.

It has become more visible in the sward in recent weeks and fertiliser application rates have been reduced to help encourage the clover to grow.

“This paddock got half the amount of fertiliser as the others in mid-June, so it was only around a quarter of a bag per acre.

“It will get another dusting later on to help build grass for tupping in the autumn,” Clement said.

Breeds match land types in closed flock

Clement Lynch runs a closed flock of 530 ewes across different land types on his upland farm in Park, Co Derry.

Between owned and rented land, the farm extends to 215 ha, with 60 ha of this categorised as improved grassland.

There are 180 Blackface ewes in the flock, with 120 of these ewes tupped with Blackface rams and the remaining 60 ewes are crossed to Bluefaced Leicester rams to produce Mules.

There are 100 Mule ewes in the flock and these ewes are tupped with Suffolk and Texel rams.

The main ewes in the flock are Suffolk-Mule or Texel-Mule crosses and these are grazed on the best land on the farm in the paddock system.

Clement tags all lambs at birth and weighs them regularly. His electronic weigh-bridge is linked to an EID tag reader and performance recording software.

“Decisions on keeping replacements are mainly based on liveweight gain over the first eight weeks. I try to use performance recorded rams too if I can get them,” he said.

At scanning, crossbred ewes tend to average around 185% and the Blackface flock sits much lower at round 125%.

There is an issue with barren ewes among the Blackface flock, so Swaledale rams have been introduced in a bid to add hybrid vigour and improve fertility.

With the exception of ewe lambs that are being kept for replacements, all lambs on the Lynch farm are kept through to finish.

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