Beating the Autumn Feedgap with Saltbush at Yealering

_This project is complete. If you would like to read the final report, click on the following link [Optimising the saltland pastures systems for profitable use](http://landwaterwool.gov.au/index.php?q=node/293)_.

Woolgrowers in the Great Southern region are trialing saltbush-based pastures in a bid to simultaneously fill the costly autumn feed gap and kick goals for the environment.

In an effort to improve production and profit from grazing saline land, a Land, Water & Wool Sustainable Grazing on Saline Land (SGSL) on-farm research project is working on saltbush and understorey species to come up with the perfect mix to fill the autumn feed gap.

Project leader Dr Ed Barrett-Lennard, who is one of Australia’s leading salinity research experts, said the new research could stop the costly practice of hand feeding grain to sheep during autumn for many growers in the region with salt-affected land.

Properties belonging to Yealering woolgrowers, Chris Walton and Kim Melvin, are among those trialing the research but the benefits will be applicable far beyond the Shire boundaries.

According to Dr Barrett-Lennard, the project involves a mix of agronomic and animal experiments with local woolgrowers primarily using saltbush-based pastures.

“It looks at whole farming systems, aiming to lower water tables and boost production from a wasted resource whilst at the same time increasing profitability,” he said. “The animal program is investigating animal nutrition and looking at opportunities to create productive mixtures of pasture using saltbush as one of the components.

“One of the challenges with saltbush is that it is high in protein and deficient in metabolisable energy. It is also very high in salt so we are trying to work out what we need to add to the saltbush to make it an accessible and cost-effective fodder in saline areas.”

Dr Barrett-Lennard said three options were being investigated.

“Firstly we are supplying straw or grain to animals grazing saltbush pasture. Secondly, we are growing high-energy understorey species and encouraging intensive grazing of these species simultaneously with saltbush. Thirdly, we are feeding animals with saltbush and stubble (crop residue). We believe the high protein in the saltbush will result in the animals substantially increasing their intake of stubble.”

“The agronomic component of the project involves finding answers to two critical questions: What is the effect of saltbush spacing on the water table drawdown and how are different saltland pasture species affected by different levels of salinity and waterlogging.

“To test the first question, we are trying to find the planting density ‘sweet spot’ where water table drawdown is sufficient to lower the water table to allow the growth of high value understorey.”

This first question is being answered at Chris Walton’s property on a four-hectare demonstration site. Mr Walton runs 3500 sheep on 3000 ha with grey clay soil and an average rainfall of 300-350 millimetres.

According to Mr Walton, the autumn feed gap expense is one he can live without.

“In that ‘crunch period’ during autumn I can spend up to $500 a week on hand-feeding stock. Making saltbush more palatable could save me at least $200-$300 a week, depending on what area we have,” Mr Walton said.

To find an answer to the second question, a range of species with different salt tolerances are being planted in order to quantify where these plants can best grow. One of the trial sites is on Kim Melvin’s property.

“Most years during autumn I have to feed out lupins that we have grown rather than sell them,” Mr Melvin said. “As a result of this research I hope to be able to sell the lupins and graze the sheep instead on saltbush-based pasture.”

Chris said using the research, a woolgrower would be able to find out their soil type, and follow advice about what spacing to plant saltbush.

“They will then be able to work out the drawdown on the water table, calculate the grazing value of the saltbush-based pasture and even the estimated weight gain for their sheep. This is the way our marginal country needs to be managed if we are going to be profitable.”

Profit comes into the third stage of the project, which involves economic modeling.

What do the results mean to the whole farm business? As Dr Barrett-Lennard says: “We should be able to indicate the economic value of a mixture of saltbush and other plant species. We are hoping these tests will show that putting these plants into the whole farm system is profitable - that is the bottom line. We have strong anecdotal evidence but these tests will really give us the answer.”

- First published November 2003.