Digging deep to combat salinity losses

Digging deep to combat salinity losses


Cropping News
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To see Rod Madden's property 15 years ago you would see creeping ice plant, sandfly bush and bare salt scalds taking up a majority of the paddocks.

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 Gutha farmner Rod Madden explained how the drains are full of salt water all year round, even through this dry summer.

Gutha farmner Rod Madden explained how the drains are full of salt water all year round, even through this dry summer.

MAKING an extreme investment over 15 years ago to reduce salt country has finally paid off for Gutha farmer Rod Madden.

Digging 20 kilometres of salt drain, four metres wide, with a 47 tonne excavator has dropped the salt water table from 10 centimetres below ground to 2.5m below ground.

To see Mr Madden's property 15 years ago you would see creeping ice plant, sandfly bush and bare salt scalds taking up a majority of the paddocks.

About 1200 hectares of the property was claimed by salt after clearing in the late 1940s and early 1950s.

Tree lines of 15 to 20 metre high York gums weren't cleared but they too were claimed by

the salt.

"There was a balance in nature between the amount of rainfall and the amount of water that came back out of the soil into the natural vegetation," Mr Madden said.

"There was always a high water table but once we cleared the land and only cropped at winter time, where the winter cereals crops didn't take a lot of moisture out of the ground and only took in what fell over the winter time, the salt rose.

"Once you had summer rains, the water table rose to the point that it bought all the salt water up.

"Eventually you would put a crop in at winter and it wouldn't germinate."

When the salt set in, it took a major toll on the farming land available on the property, making 1000ha unarable.

"It was totally devoid of anything except for salt bushes," Mr Madden.

"There were dead trees everywhere and nothing would grow.

"I then planted some trees thinking it would help reduce the salt but it didn't.

"They ended up dying and I just pushed them over too."

Mr Madden said he wanted to reclaim "the beautiful dirt" under the dead trees and salt bush.

He set out to build a drainage system to flush out the salt water and reclaim the soil.

Over 10 years Mr Madden built 20km of drains and lost about 8ha by the time the drains were dug through paddocks.

Mr Madden said that was a small price to pay compared to the gains he made.

"We spent a fair bit of money here but we were certain we would get it back," he said.

"Our crop went 2.4 tonnes per hectare last year and beforehand it was just useless salt land.

"There is a huge amount of capital outlay that you won't get a return on for maybe 5-10 years.

"But I wanted to do it, I did and now my farm is better off for it."

For the first five or six years after the drains were built, Mr Madden had to find a place for the water to go.

Originally he pumped the water, at 3.6 tonnes per minute, into an evaporator pond that covered 37ha.

"I would pump millions and millions of litres into a huge evaporation pond but I couldn't cope with the amount of water," he said.

Since then he found a solution, with the help of neighbours, to drain the water naturally through to the Yarra salt lake system at Gutha.

"Now millions and millions of tonnes of water have just gone down the drain, literally," Mr Madden said.

"It's running into the natural salt chain and has created a better flow on for the drainage system."

To clear the land of salt bush Mr Madden used a Kelly chain and smashed up all the bushes then set it on fire.

"We haven't grown anything on this land here, except for the past few years, since the mid 70s," he said.

"In this paddock, which is 87ha, I would only crop 32ha of it.

"Now I am cropping all of it and getting returns of three tonnes per hectare."

Mr Madden said this was a similar situation in most of his paddocks where the drains had successfully reduced the salt.

With the water table down at 2m, it's still enough for the salt bush to get its roots down and keep growing.

Mr Madden is burning the stubble and any random bush this year to try and clean it up.

He also has test probes all over the farm to measure salt levels.

"Every 50m, 75m, 150m and 250m away from the drain is measured to see the affect of the draw down of the salt in the proximity of the drain," he said.

"When we first started we were expecting a good draw down from 40m but we weren't expecting it out to 100m and this draw down went all the way to 250m.

"It wasn't as good but you can still see results.

"Places where plants wouldn't grow now have thick stubble covering the ground."

At least six other properties in the area have started to invest in drainage work.

Mr Madden said there was still a bit of work to be done but it's certainly not as depressing as it used to be.

"I used to come down here and see dead trees and just unarable land," he said.

"Now I have about 100ha left to clean up and everything is much better for it."

Mr Madden said he hoped to one day see trees again growing near the drains.

This year he will be cropping 4000ha of wheat, barley, canola and lupins, as well as running a couple of thousand sheep.

He keeps the sheep away from the salt drains for two reasons.

Rod Madden said there is about half a metre of water here and its just coming to the end of summer.

Rod Madden said there is about half a metre of water here and its just coming to the end of summer.

"One is because they get stuck in the drains and the other is we haven't got good water down there for them to drink and they need fresh water if they are to thrive," Mr Madden said.

"I have plenty of acres that I don't need to run them that hard."

Lately Mr Madden has been doing a bit of fencing and preparing for the upcoming seeding program.

He is also continuing to reclaim land, pushing up salt bush with a stick rake and clearing out all of the dead trees from around the salt plains.

"It's pretty marginal farming out here," he said.

"It's beautiful loamy red soil if it just gets wet."

This year Mr Madden has received two millimetres of rain so far and plans to seed his program dry with a quick application of Treflan.

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