Experiment with tree lucerne

Press, 1 March 1984, Page 19

Experiment with tree lucerne

Bill Manson’s attempt to start a nursery business high on Huntsbury Spur in the Port Hills is a conspicuous sight because he is up there almost on his own, working from an old railway guardsvan used as a store shed, and another building that he put up without a permit. He has already put 3000 Tagasaste plants into the ground on the four-hectare block of land he bought recently, and there is room for more. A 33-year-old builder whose arthritis keeps him from practising his trade the way he used to, Mr Manson is experimenting with growing the plant — commonly known as tree lucerne — for shelter and fodder. If trials are successful, he may be able to start a nursery on the hillside land, part of the 106 ha block bought by a Christchurch man last year as the base for a future horticultural community. Planning barriers stand in the way of the new business, since future zoning and permitted activities in the present Heathcote County special development zone are uncertain. Some want to see part-time farming allowed, Mr Manson among them, while others lean toward more rural-residential uses. Mr Manson is carrying on in spite of all the uncertainties. He’was looking for a plant that could act as a shelter for later horticultural crops. The D.S.I.R.’s Crop Research Division at Lincoln suggested Tagasaste, which comes from the flanks of a volcano in the Canary Islands. He has also received City Council small business planning advice from a volunteer counsellor in horticulture. The Crop Research Division had suggested that the hillside land might be used as a nursery to grow the crop properly, he says.

Since before Christmas, he has been planting in rows from seedlings grown at his home in St Albans. He has a friend who will come in with him when the plants mature, to do the heavy work. “If farmers get in on the idea of growing it as a fodder crop, there would be employment for other people, too,” he says. “Two of us couldn’t plant all that would be needed." He already has tentative orders from two farmers. When Mr R. T. Shiels bought the Huntsbury Spur block last year, he said he wanted future buyers to form a vegetarian community, “and I had been a vegetarian for years,” says Mr Manson. Tagasaste is a good nursery crop that also provides shelter for other growth, such as native plants, growing underneath it. Then the tree lucerne can be cut out. It makes good firewood. “It’s a pretty pioneer thing,” he says. “Nobody knows a lot about doing it. It has all sorts of advantages, for bees and birds, even as a biogas feedstock. It has the same biogas rating as chicken manure.” Mr Manson says his next job is to build a tunnel house for the nursery. Getting enough water for the proposed nursery will be the biggest problem. With the Spur zoning question so up in the air, Heathcote County is in no position to say what it might do about eventually reticulating the area for a water supply. “It’s water that’s the trick,” says Mr Manson. “To get me going, I’ll get water off the roof of the woolshed, if necessary.” There is an existing woolshed up the hill. ' Water could also be carted up from below, collected in tanks or brought from an earth dam reservoir nearby. Because of Heathcote County

and Christchurch Civic Trust proposals for a large park in the Port Hills, from Victoria Park to the Rapaki Track, “there is a lot of concern about what's going on here,” says Mr Manson, and he understands that concern.

A park would run down two sides of the Spur, connecting across the top. The Spur block “needs an overall landscape plan,” says Mr Manson. “It should be designed to look good from the city, instead of being a patchwork.” When he first put the guardsvan on the slope, it had its distinctive red colour, and drew remarks from residents below. He has since painted it grey, so it will blend in better against the hillside. Mr Manson says that Tagasaste fixes nitrogen in the soil, providing nourishment for plants growing around it. Because the crop has deep roots, its need for water is not so great after it is planted out. Tagasaste is so delectable to

animals that young plants have to be protected from the attentions of rabbits and sheep. Ways to grow it in fenced shelter belts so that animals graze only around the edges are part of the studies being done at Lincoln.

Mr Doug Davies, a Crop Research Division scientist, says the plant has lucerne-like leaves, but it is not related to lucerne in any way. Tagasaste is well known in the temperate states of Australia.

The division has been doing research on the nitrogen-producing legume tree since the mid-19705. “My view is that New Zealand had such a fight with gorse and broom as shrub legumes — they cost millions to eradicate — that tree lucerne didn’t catch on." says Mr Davies. “It has to be protected from continual grazing.” Tagasaste grows about 2m a year in high fertility soils, and could grow from half a metre to Im on the Port Hills.