THE Currie family of Dergholm hope planting perennial tall wheatgrass hedgerows in one of its paddocks will boost lamb survival and lamb weaning percentages.

David and Mary Currie, with their sons Tim and Richard, planted the shelter-strips after successful trial work at the Hamilton's Department of Primary Industries' EverGraze site.

    AT A GLANCE
  • Who: the Currie family
  • What: planting perennial grass hedgerows
  • Why: boosting lamb survival rates
  • Where: Dergholm
  • Report: KATE DOWLER

The grass plantings on the family's property are thought to be one of the first broadscale attempts to replicate what has only been a trial-size concept.

And as keen young farmers, willing to have a crack at something new, Tim and Richard are waiting for the grass rows to grow so they can try their first lambing in the sheltered paddock next year.

Research has shown growing perennial grass hedgerows on the Hamilton EverGraze system reduced twin-lamb mortality by almost 40 per cent in both Merino and Coopworth ewes.

The hedgerows work by reducing the chill lambs are exposed to during cold months, therefore boosting their chance of survival.

The rows have been proven particularly beneficial to multiple-lambing ewes and their offspring.

"We had to renovate this paddock anyway, so why not give the hedgerows a go, it is not a huge outlay, and if it works, should be a good benefit," Tim said.

The 45ha paddock the Curries chose to renovate is on the contour of a hill, and was first prepared by sowing two cereal crops to control weeds such as onion grass, barley grass and cape weed.

They are currently renovating a portion of their less-productive areas, half in spring and half in autumn. New pastures are expected to last for a decade before requiring resowing.

"We expect the cost of renovation to be recovered within three years," Tim said.

The paddock was sown last spring with a sorghum crop so that ryegrass and fog grass could be cleaned up.

Then, this May they sowed the tall wheat-grass rows at a rate of 12kg/ha, with 1m wide rows, spaced at 10m apart across half the paddock and at 20m on the other half.

"Finding shelter is a big issue for twinning ewes, so this will be used for ewes that are scanned as twinners and separated," Tim said.

The pasture between the rows was sown as holdfast GT and landmaster phalaris at 2.5kg/ha, 2kg/ha of cocksfoot and 6kg/ha of subclovers.

For the past three years the Curries have been using liquid fertilisers.

Tim said it was a cost-effective method, particularly when fertiliser prices skyrocketed a few seasons ago.

"Our soils are also low in calcium, so using soluble calcium is of more benefit," he said.

"We've found that lighter sowing rates and liquid fertiliser also help to encourage early root growth and larger plants that tend to be hardier and will survive, instead of many small plants, of which many die."

Tim said the hardest part was going to be learning how to manage the hedgerows throughout the year.

The plan is to allow a rank stand of tall wheat grass to be maintained and not damaged by stock, while the rest of the pasture is grazed, or cut for hay.

Twinning ewes will be put in the paddock for a period leading up to and after lambing, when lambs are at their most fragile.

"We hope we can leave the paddock to run to head in spring; perhaps cut for hay the first year, and that from then on the ewes will graze the pasture and not the rows," Tim said.

Grazing cattle in the paddock is expected to be off the cards.

"We aren't really sure how it will work, so it will be a case of wait and see," Tim said.

"We hope that the tall wheat grass is unpalatable and so the stock concentrate on the pasture in between."

Richard believes the hedgerows will be worthwhile because they will optimise the reproductive efficiency of the herd's MultiMeat genetics.

"With the MultiMeats we expect to lamb 180 per cent upwards, and 80 per cent of these ewes are bearing twins or triplets," Richard said.

"The two biggest causes of lamb deaths are weather and foxes, so the hedgerows are trying to control one of those.

"But we do have concerns about how to manage this on a large scale."

The maternally-strong and fertile MultiMeat rams are used over first-cross ewes and Merinos in the Curries' flock.

Last year their first ewe lambs from this cross scanned at 160 per cent and weaned 100 per cent, a remarkably high rate for maiden ewe lambs.

"This year the ewes scanned at 185 per cent, so we have to manage all these lambs if we are pushing for high percentages," Richard said.

"The challenge at the moment is managing litter size, we don't want to push condition too high, or we could have 200 per cent and that could be a challenge.

"So we have to limit condition at joining, and hopefully keep it around 185 per cent."

Richard said their broadscale hedgerow experiment was a bit of a gamble.

"Out of about a 40ha paddock only 1.5ha is sown to the tall wheat grass, so it's not a huge cost if it doesn't work, and if it does, the benefits could be great," he said.

The Curries recently hosted a Best Wool Best Lamb field walk at the site. Members of the group were enthusiastic about the potential of the hedgerows.

"You have to give these things a go, otherwise how else do you ever know what might work out worthwhile to help improve what we do," Tim said.