A WINTER growing perennial legume with non-bloating characteristics is showing promise as a winter forage option - and potential alternative to lucerne - in a trial on the Darling Downs.
Red-flowered Sulla, native to the Mediterranean and widely grown in New Zealand, is being assessed for its potential as a short term rotation in Australia's cereal cropping systems.
CSIRO farming systems scientist, Lindsay Bell, Toowoomba, said Sulla was a winter-growing temperate legume which was similar to lucerne but without the risk of causing bloat in cattle.
"We have been testing it for a few years in southern Queensland to see where it might play a role in northern cropping systems," he said.
"It is a short-lived perennial. It probably fits as a two or three-year phase in a cropping system.
"In the past we have seen variable persistence from year one to year two. Some seasons it has been quite good and some seasons less than what you would hope, with only 10 to 20 per cent of plants surviving.
"So one of the challenges is how you manage Sulla to maintain persistence and maximise productivity. That is still to be refined."
In the trial on the Noller family's farm at Pilton, south of Toowoomba, Sulla is being grown alongside a range of other forage legumes such as snail medic, vetch and peas.
Dr Bell said one of the aims of the trial was to see whether forage legumes could be integrated into cropping rotations co-sown with a forage cereal like barley or oats, or whether they had to be planted as a pure sward.
"We are showing here that most of the legumes are really constrained when you co-sow them with a forage cereal. The competition is too high," he said.
Dr Bell said with Sulla it should be possible to achieve 50 to 80 days grazing, particularly in a rotational grazing situation.
"You have to get it up to where it is about 30 to 40 centimetres high then graze it. There seems to be a trade-off between setting seed and persistence. At this stage we think you are probably better off grazing it rather than letting it try to set seed," he said.
"We don't have any definitive data on livestock production from it as yet in this environment.
"Data from overseas suggests you get equal or higher production than lucerne with a range of other benefits, including a hay option. It makes quite good hay. It needs to be dried a bit longer than lucerne but it keeps its leaves a bit better."
Sulla is best suited to neutral to alkaline clay soils like those on the Darling Downs and not so suited to acidic or sandy soils.
Dr Bell said the optimal sowing time was mid-April to the end of May at five to eight kilograms a hectare.
"We have been testing different rates to see what the return is, given the seed is quite expensive," he said.
Three Australian varieties have been commercialised in recent years: Wilpena, Moonbi and Flamenco.
The trial at Pilton has also been testing a range of forage brassicas, which Dr Bell said had shown particular promise compared to some of the winter cereal forage options producers might normally grow.
"In particular, they have significant benefits in controlling nematodes and crown rot in cropping systems," he said.
"We have tested a kale which is commonly grown in New Zealand and three forage brassica varieties. They have all shown similar production levels and are quite competitive with weeds."
