Lamb Finishing on Lucerne

Greenfield is the largest lucerne grower in New Zealand and uses lucerne for finishing stock in a dryland environment.

Greenfield is a Blenheim-based agribusiness investment and management company. Part of their large portfolio consists of 20,000ha of land in Central Otago which is used to contract graze stock. A large portion is now planted in lucerne none of which is irrigated. Hills Creek Station is a typical example of its operations in Central Otago. This summer is particularly dry in Central, and some locals say this is the driest time in 90 years.

Interview with Warren Taylor, Greenfield Managing Director:

We are a grass factory, with inputs and outputs. Our aim is to economically grow as much energy as possible and utilize as high a percentage of this energy as possible.

We work hand in hand with the environment in an economically and environmentally sustainable model. We match our systems and species to best fit a hot dry summer and cold harsh winter rather than wasting energy and expense fighting against what nature has given us.

This involves matching feed supply curves with a feed demand system to maximize productivity and profitability. The growth period is from late October to April.

During the winter the land is destocked and spelled to maximize the longevity of the pasture sward, and to negate environmental issues such as erosion, damage to soil structure and run-off into waterways.

We would argue that it is better to grow 8tonnes DM over four months that it is to grow 5tonnes over nine months. It is more about utilization and putting a system in to best utilize that 8tonnes.

The Maniatoto rainfall is said to be from 500 to 600mm/year, but in the six months to the end of December only 161mm fell, which is not a lot.

Water is a very valuable resource in these dry climates and its imperative that we maximize energy output from water input and lucerne offers this over traditional grassland pastures.

What we are trying to do is offer part of the whole puzzle to the industry: there is a lot of good quality breeding country around NZ, and with all the dairy conversions etc, there is a diminishing amount of finishing country.

We are developing long-term sustainable relationships with repeat customers who see the benefit to both parties.

We are offering an alternative to breeders who are looking for higher returns, for example we graze for farmers who would otherwise be competing on the store market where they have to cope with its fluctuations.

This is a way to share and maximize - the wealth creation by linking it all together. We want to build relationships which benefit both parties by adding value to their product.

We are not looking at being the most expensive, but the most sustainable year in year out.

About half of Greenfields business is direct with farmers, the other half with meat companies.

Hills Creek Station is typical of how all Greenfield property clusters in Central Otago are run.

Hills Creek is 3927ha, of which almost all, at 3783ha is effective. It runs from 440 to 860m above sea level, and was put together by the purchase of three adjoining farms over a year to March 2008.

Of this total area, 2046ha is now in lucerne or lucerne mixes. Previously this country was dominated by browntop or hieracium.

As part of the improvement large areas were direct drilled to conserve water, and protect against wind damage. The objective is to be as environmentally sustainable in what potentially could be a fragile environment if the land is not treated well.

Hamish has more farm to farm grazing than most Greenfield farms, and he deals directly with farmers. In the year to December, Hamish had 17 different local farmers he was grazing stock for, and also some for the meat companies, predominantly Silver Fern Farms and Alliance.

Last year he finished 47,000 lambs, as well as running 12,500 ewes for a variety of customers and about 1100 beef steers. He also made just under 3000 big square bales of lucerne, most of which is sold rather than used by the farm.

The stock are coming and going to fit the feed supply, and relive pressure on people who may be short of feed because of drought or the way their system operates.

We do a lot of ewe hoggets for people to get them up to target weights, and we finish a lot of lambs for people who are sending them on to the works. Weve also run some stud cattle for several years.

Hamish has two shepherds working with him, and he uses a lot of local contractors for fencing, fertiliser and cultivation. Apart from a ute, bikes and a few dogs, there is no plant and equipment at all.

Interview with Julie Kearney, Greenfield Senior agronomist:

Lucernes water use efficiency is a key reason we use it: it is a lot more efficient at converting limited water into dry matter compared to other grassland species.

Ryegrass pastures grow 5-10kg of drymatter per mm of water, but lucerne can produce 20-30kg of drymatter per mm of water.

Julies measurements to date show some of their lucerne is growing 29kg DM per mm of water. That shows they are converting that moisture as efficiently as they possibly can. Its really exciting to see that it is working.

The 29kg is the acid test. If we werent managing our stands correctly they wouldnt have the root resources to grow effectively.

We measure soil moisture every month from the pasture cages with a hand held probe which goes 15cm down into the profile.

Lucerne also has a very deep root system, so it not only converts rainfall very efficiently but the deep roots mean it can access more available water from the soil profile than traditional pastures have been able to access.

It has very high metabolisable energy (ME) values, and its a high protein forage feed. Its ideal for lamb finishing, because not only does it produce more dry matter, its leaves have an ME value of around 12.5.

With good grazing management, the stock will be harvesting really high energy feed and in turn the lambs will grow faster. Its a win win for everyone.

Growing stock as fast as we can is a really important to our whole system, because in order to reach target weights less inputs are required. That means return per unit of input is greater.

Lucerne is a Mediterranean plant, and has been grown in NZ since the 1960s. But its use dropped off through the 1980s, thanks to diseases and aphids. The newer varieties now in use are more resistant to pests and diseases.

We are not seeing the problems that past generations of farmers might potentially relate back to lucerne.

Management of lucerne is really critical, and all the Greenfield managers have a good grasp of how to get the best out of the plant. The management is very different to that of other species.

Three important points about its management:

1. it has to be rotationally grazed with a rotation of only five to seven days; it cant be set stocked.

2. its really important that the plant is allowed to flower after Christmas, which puts carbohydrates back into the roots for optimum production the following spring. If you dont allow that to happen you wont get a good spring flush

3. lucerne needs fairly good fertility for it to thrive: phosphorus levels in the high teens, and ideally a pH over more than six. Otherwise you have problems with aluminium toxicity in Otago soils.

Some of the farms prior to Greenfields ownership may have only grown 2-3 tonnes of dry matter per ha, but now the lucerne is growing in excess of 8 tonnes and last year some paddocks grew 9.5 tonnes. For dryland production that is pretty impressive. We budget on growing 8 tonnes and budget has been achieved and ahead of schedule.

At Hills Creek we finished sowing the last lucerne paddocks in November 2009.

Julie works closely with Professor Derek Moot, a lucerne specialist at Lincoln University. She did her honours degree there in lucerne.

And Greenfield has just been joined by a top pasture specialist Dick Arnst, who previously worked for PGG Wrightson as an agronomist for many years.