SUMMER-ACTIVE tropical and subtropical grasses more commonly found in Qld may help fill the summer feed gap and stabilise soils vulnerable to erosion on mixed-farming properties in the SA Mallee.
That is the finding from research by the Future Farm Industries CRC in its EverCrop project led by CSIRO which has examined rhodes grass, gatton panic, bambatsi panic, petrie panic, digit grass, strickland finger grass and purple pidgeon grass.
Since 2009, they have been grown in monocultures in trial plots at Karoonda and found to have good persistence, and can produce out-of-season feed particularly in a few weeks after summer rain.
Work was also undertaken by the CSIRO and Birchip Cropping Group in another low-rainfall region at Hopetoun in the Vic Mallee from 2006 to 2013 using these same species.
CSIRO researcher Andrew Smith, at the Waite campus of the University of Adelaide, said these grasses had a potential role as a "niche" perennial pasture.
"They are not for every farm and not for, all of the farm, as Mallee farmers, main business is growing crops, but they may be suited to parts of the farm prone to soil drift and certain farming systems."
"If you can get lucerne to grow and continue to grow year after year and you know how to graze it, it is no doubt your best option but there are cases where it is not an option and so we need to be thinking about the alternatives," he said.
"These grasses can be an alternative to costly feeding," he said.
Dr Smith acknowledged that their nutritional value was lower than temperate species, but good nitrogen fertility and good grazing management of the soil could raise feed quality.
"They have different growth patterns to temperates and because they grow so quickly there are really opportunities after summer rainfall which we get in the Mallee every few years," he said.
Karoonda's annual rainfall was about 300 millimetres but the project had a large variation in summer rainfall from year to year, from 28mm in 2012-13 to 106mm in 2013-14.
Dr Smith said models (APSIM, GRAZPLAN) had been used to assess the potential feed value across a number of different climate years and soil types.
He was looking for interested Mallee farmers to participate in paddock-scale trials to further understand the potential role of these grasses in the Mallee.
"We have a little bit of money to assist some farmers to try them with their own equipment, seeing how we can incorporate legumes such as medics into the mix to improve fertility and understanding how to get the best out of them for livestock," he said.
* Full report in Stock Journal, April 10, 2014 issue.