Mid-winter may not be a good time to highlight a late spring, summer and autumn growing perennial grass, in southern NSW.
Yet in a southern NSW tour, organised by NSW DPI's Sarah Baker and Katrina Sinclair, I was overwhelmed at successes and enthusiasm for tropical grasses.
Large scale tropical grass pastures at Henty and Lake Cargelligo, as well as research at Condobolin and Wagga Wagga were inspected.
Most of the tropicals were premier digit grass. Ongoing research, led by Dr Suzanne Boschma, supports that premier digit is likely to be a main long-term persistent species in southern areas, as it is for much of the central and northern parts of the state.
Several farmers stressed to us that their strong support for tropical grasses included that over the past 30 years summer rain has been more frequent than long-term rainfall records indicate.
Even if rainfall trends return to less summer rain (no forecasters are suggesting this) southern farmers and agronomists felt there has always been enough summer rain to favour at least some summer growing pastures.
That winter legumes like sub clover, medic and serradella coexist well with tropical grasses, especially in a southern rainfall environment, indicates that normal winter spring growth from them is hardly likely to be much compromised.
These not only supply winter spring feed but are able to supply much of the nitrogen required for high quality tropical grass feed.
An example of top quality tropical grass feed was analysed at Condobolin of premier digit grass in March. Crude protein was 20 per cent and metabolisable energy (MJ/kg DM) was 12.3.
These are high figures, although not as good as high quality lucerne, and indicate likely growth rates above 1kg/head/day from weaner cattle.
Several farmers indicated that tropical grasses for them were more for lighter and shallower soil parts of their properties where crops preformed less reliably (store less soil water).
Also areas with acidic soils, especially where sub soil acidity was also an issue and hard to correct, especially suited acid soil tolerant tropical grasses like premier digit.
A few agronomists have played a major role in encouraging southern farmers to try tropical grasses.
Henty agronomist Nathan Soulsby and Lake Cargelligo agronomist and farmer Andrew McFadyen, emphasise the importance of establishing tropical grasses in seed beds as weed free as is practical.
They stress the importance of choosing paddocks that are kept weed free over the summer fallow for at least two and preferably three years before tropical grass sowing.
This means timely herbicide control of summer weeds, and in wetter summers up to five weed control treatments.
They also preferred sowing early, around early November, to maximise probability of receiving good establishment following rain.
Read more: Time for a re-think on pastures
Lake Cargelligo farmer Terry Mann stressed his Dorper lamb enterprise required high quality feed following rain events whatever part of the year they fell.
Tropical grasses are providing this from mid-spring to the end of autumn.
This is important if high and frequent lambing rates are to be achieved, with good progeny growth rates.
Steven and Cindy Scott, Glen Elgin Angus stud, Henty, have established several hundred hectares of premier digit with plans for expansion.
Tropicals compliment their other pastures, including temperate perennials like phalaris, but are filling a valuable role in proving late spring, summer and autumn feed.
Next week: Coping with climate change or climate variability.
- Bob Freebairn is a Coonabarabran-based agricultural consultant, email robert.freebairn@bigpond.com or call 0428 752 149.
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