Wheatbelt Woolgrowers in Trials to Halt the Salt!

_This project is complete. To view the final report click on the following link [Does grazing on perennial pastures on saline land affect farm salt and water balances? ](http://landwaterwool.gov.au/index.php?q=node/314)_.

Woolgrowers in the Central Wheatbelt are involved in cutting-edge agricultural research which is aiming to take land under the threat of salinity and make it a key area of profit within their farming system.

The research project ‘Profitable grazing whilst alleviating salinity’ involves setting up a grazing system that alleviates the threat of salinity and gives best live weight gain and wool production from Merino weaners.

The research is being carried out on Deane Aynsley’s property near Quairading. According to Deane, the region has an area of land that is becoming saline very quickly.

“We wanted an option to keep this land within our animal production system whilst preventing it from becoming more saline,' he said. 'This project gives us that opportunity. We are also hopeful that as a result of this project we will be able to reclaim some land that is already saline.”

The Aynsleys farm 8000 hectares in the Beverley shire. “We are a typical wheatbelt mixed enterprise property,” Deane said. “We are mainly dedicated to sheep (prime lambs and wool) however due to the drought our numbers are down and it has been difficult to build them up again. That is one of the reasons I am keen to see perennial pastures introduced as they will give us some feed during the summer.”

SGSL team member John Paul Collins said there are three treatments that are being carried out on the partially saline land. “One plot is growing lucerne, the second unimproved annual pasture such as barley and annual rye grass, and the third involves sub-tropical perennials and saltbush alleys,' he said.

“We will then carry out a series of grazing trials on these plots once these species are established. There is also an adjoining area to the trial where no treatment is being used and this is the control or do-nothing area for comparison.

“The sub-tropical perennials and saltbush site consists of direct sown saltbush on mounded soil (niche seeded) and with the perennial grasses sprinkled alongside the mound. The research that is taking place into sub-tropical perennial species is of particular significance because there is very little known data about their performance in the WA wheatbelt.”

John Paul said local growers’ report salt seems to come to the surface particularly after wet summers and this is why growing sub-tropical perennials could be very helpful.

“Many of the farmers in this area noticed that the saline land rapidly expanded on their farms after the January 2000 floods,' he said. 'These summer flood events contributed large amounts of water to the groundwater when there were no plants actively growing in the paddocks to use it and therefore prevent a further rise in the water table.

“The idea for trialing the sub-tropical perennial grasses, which are dormant in winter and actively growing as temperatures increase is to reduce the water table during summer.”

Deane agrees with this theory. “We noticed that a major salinity onset occurred after the wet years of 1998-2000, indicating that salts stored in the water table had been brought closer to the surface as a result of the higher rainfall.”

According to John Paul: “this project has a livestock focus and weight gain and condition score will be regularly monitored. The feed on offer and pasture quality with regard to the degree of digestibility and level of protein will also be monitored.

“We have already learnt a lot about establishment of the different species. For instance with the lucerne in particular we used a single disc zero till system with disappointing results. However with establishing the perennial grasses we had much better germination rates where we had ripped up using a scarifier compared to not ripping as experienced with the lucerne. So it appears that a prepared seed bed is more successful and we will try this again on the lucerne next year.”

Deane said the three-year duration of the project enables it to cater for seasonal variability.

“It is all about halting the spread of salinity whilst maintaining the health and production of the areas. We need to explore the options in dealing with land that has this degree of salinity other than taking it out of production and into trees,” Deane said.

“Similar to many farmers in the district we have increasing amounts of land that is at various stages of salinity and we are all keen to work out the right management and treatments to keep it productive. We have to try and that is what this project is doing. If we don’t try the land will become too saline in two to three years and will be worth nothing to us.

“We are still feeling our way of course but we are hopeful that this is the way of the future for us.”

First published December 2004. For more information go to the Sustainable Grazing on Saline Lands Sub-program.