Meet a lucerne scientist

Date posted: 01 December 2015

This month we interviewed Alan Humphries – feed and forage leader at the South Australian Research and Development Institute (SARDI). He manages the National Lucerne Breeding Program and, with more than 15 years’ lucerne experience, we thought he’d know a thing or two about our crop!

Why is lucerne a major focus of your job?

Lucerne’s a nutritious, perennial [it lives for more than two years] legume and a major grazing crop grown by farmers to feed livestock, including dairy and beef cows, sheep, horses, pigs and chickens. Lucerne seed is also sprouted and used for humans to eat – alfalfa. Basically it’s an amazing plant for feeding both humans and animals globally. There are 2.5 million hectares of lucerne grown in Australia for grazing and hay production [that’s more than 1 million Adelaide Ovals]! Farmers need varieties that are suited to Australia’s tough growing conditions, which is why my role is important.

Run us through your day-to-day role.

My job’s to develop new lucerne varieties. I travel the world looking for plants with better traits, like being more resistant to disease or drought. We aim to breed varieties of lucerne better suited to conditions faced on farms – periods of low rainfall, hot winds, varying soil conditions and diseases.

A recent focus has been developing a grazing-tolerant lucerne variety, called SARDI Grazer. The initial feedback from farmers is exciting – we’ve developed a variety that has much greater persistence on farms under grazing [feeding from the ground by animals].

How does a grazing-tolerant plant work?

A grazing-tolerant plant is less at risk of the physical damage caused by livestock. Grazing plants have a tough job… animals stomp on them, bite them, tear their leaves off and chew them up! Traditionally lucerne required a grazing system where the paddock might be grazed for one week before the cows were moved to another paddock, leaving the plants to regenerate for about six weeks. But with new varieties plants can be grazed for six weeks or more.

We selected the variety from plants that survived continuous close grazing by sheep for two years. The survivors were found to have a lower crown [where the plant stem meets the roots], which means it’s harder for the sheep or cows to cause damage that could kill the plant. These plants have the ability to maintain energy levels during grazing. We think they store energy in their tap root [a thick root that goes deep into the soil] and then use it when under the stress of grazing to maintain growth.

Why’s lucerne so important in SA?

SA’s the lucerne seed production capital of the world! About 7,000 tonnes of seed [the weight of more than 11-thousand dairy cows!] are produced each year - some of which is kept in Australian for food, farming and livestock, while the rest is sent to places like the Middle East, South America and South Africa.

Where has your work taken you?

Travel’s an amazing part of my role. I am currently working with the Global Crop Development Trust in Germany, which focuses on the impact of climate change on food security. We look all over the world for wild relatives of crops that are common today that may have tough or unique genes, such as an ability to survive with less water and more heat. We have been to places like Chile and Kazakhstan and we’re working on their behalf to develop varieties which suit their challenging conditions.

How do you keep track of all these seeds and varieties?

We work closely with the Australian Pastures Genebank, located at SARDI in Adelaide, which stores more than 80,000 packets of seeds from all over the world. We’re lucky to have this resource because it means we can retain plant diversity and draw on old varieties at any time. Currently we’re fortunate to be working with nine packets of seed from London’s Kew Gardens – the world’s largest collection of living plants [and a partner of the South Australian Seed Conservation Centre at Adelaide Botanic Garden].

And finally… what are some interesting lucerne facts?

1. Lucerne tap root can grow seven metres into the soil! This makes it a relatively drought-tolerant plant as it can access stored soil moisture.
2. Lucerne’s a dicot plant, originally cultivated by the army, which has been used for thousands of years to feed horses. Soldiers saw that if horses were well fed they were quicker and faster in battle.
3. When managed correctly, lucerne can be grazed on rotation for up to 20 years. The key is to manage how intensively the lucerne is grazed so the plant can maintain its energy levels.
4. Adelaide Botanic Garden’s City Crop is 425 metres², which means you could make 2,429 ice cream scoops from the milk produced from a cow grazing the plot!

NOTE: Alan’s work was undertaken as part of the initiative “Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives”, which is supported by the Government of Norway. The project’s managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew and implemented in partnership with national and international gene banks and plant breeding institutes around the world. For further informationsee the project website.