Native Grasses Critical to Woolgrower Profitability in the Mid North

_This project is complete. Click the following link to view the respective document [Revealing the secrets for profitable, productive native pastures in the Mid-North](http://landwaterwool.gov.au/index.php?q=node/122)_

South Australia’s Mid North region is the location of a new grower-focused research project aimed at lifting woolgrowers’ profits through improved grazing management of native pastures.

Some growers involved aim to achieve significant increases in pasture utilisation rates - doubling current rates in some cases. The project 'Managing native pastures in South Australia for improved animal production and biodiversity' will help woolgrowers to conserve and improve native pasture biodiversity by rotational grazing, and boost profits through increased production.

According to project investigator, Millie Nicholls, from the Mid North Grasslands Working Group, about 300,000 hectares of native grasslands in the Mid North of SA are grazed. The rainfall varies across this region from 250 millimetres up to 500mm.

“Generally native pastures in the hill areas of the Mid North are continuously grazed during winter to fit in with the cropping program,” Millie said. “This has reduced the population of native perennial grasses and produced pastures dominated by undesirable annual grasses such as wild oats and barley grass.”

The project area currently involves seven demonstration farms stretching from Robertstown in the Mid North up to Carrieton in the Upper North. An experimental site has also been established near Clare. One of the woolgrowers involved in the project is Rowan Cootes, whose family own a 1200 ha farm near Spalding in the Mid North.

The Cootes family crop about 800 ha and run a self-replacing Merino flock with a total Dry Sheep Equivalent (DSE) of 3,500 (winter-grazed). The property’s annual average rainfall is 450mm.

According to Rowan, he became involved in the project due to concerns about the detrimental impact set stocking was having on their grazing land in the hills on his property, which totals about 250 ha.

“Large areas of capped soil were developing, there were increased numbers of weeds such as thistles and we had poor pasture utilisation in parts of the paddock due to patch grazing by our sheep,” Rowan said.

The Land, Water & Wool grazing trial builds on an initial project, funded by the National Heritage Trust (NHT), where large paddocks were sub-divided and improvements made to stock watering systems. By using the same sites, the LWW project will generate one of the few long-term trials on grazing regimes in native pastures.

“The growers are rotationally grazing their sheep through each paddock, according to pasture growth, with emphasis on an adequate rest period to allow the perennial plants to recover from grazing,” Millie said.

“By managing for a perennial-based pasture rather than an annual-based pasture, which is what occurs with set-stocking, we should see an increase in the health and numbers of each perennial plant.”

A range of plant and soil measurements are being taken including pasture growth rate, change in native and annual pasture species, species diversity, water-use efficiency, water infiltration rates and soil biological activity to provide valuable data to growers and researchers in relation to the impacts of the new grazing regime.

The project will also include analysis of wool production and quality, reproduction rates, stocking rates and financial details such as cost of inputs and gross margins.

As part of the original NHT project, Rowan initially subdivided one 30 ha paddock into five paddocks and subsequently subdivided a further four paddocks into 16 paddocks. The water system was also re-arranged, which included the installation of a new pump, tank and troughs.

“We are now rotationally grazing each paddock according to pasture growth, working on the principle of high density, short duration grazing. For example we might run 2000 DSE in a six ha paddock about four times per year,” Rowan said.

“We are working on a minimum rest period for each paddock of about 30 days but I am aiming to achieve a longer rest period of about 50-60 days, particularly during winter when pasture growth rates are slow.”

Although it is still early days, Rowan believes the change in grazing management could have a range of benefits such as improved native pasture biodiversity and production, a reduction in bare ground and increased water-use efficiency, so more grass can be grown per mm of rain.

“At the moment we are probably achieving a water-use efficiency of about eight kilograms of dry matter per ha/mm of rain on the northern slopes and up to 15kgDM/ha/mm on the southern slopes but I believe there is potential to significantly increase our water-use efficiency rates,” he said.

“And a spin-off from increased pasture growth is the opportunity to increase sustainable stocking rates. The previous maximum stocking rate we would have achieved in our hills would have been 2.5 DSE/ha and through rotational grazing we have increased our annual stocking rate to about 3.7 DSE/ha.”

“In the past, native pastures have been under-valued but they are important for long-term grazing productivity and sustainability in many areas. They are drought-tolerant, low-input, healthy and if managed correctly will be productive pastures,” Millie said.

“We hope the project results will show woolgrowers how changing grazing management can increase native species biodiversity and generate a more robust, productive pasture which will perform better than an annual-based pasture in any season - whether wet or dry. A series of training workshops and field days will help extend the project results to a wide group of wool growers.

“The project will also help to show the financial benefits of increasing native pasture production. We believe the economic value to wool growers of rotational grazing on sheep and wool production could be considerable.”

First published April 2004. For more information go to Managing Native Vegetation and Biodiversity Sub-program.