A new soil amendment trial that aims to reduce the loss of nutrients to waterways has been established at one of the largest dairy farms in the south west of WA.
A partnership between Yoongarillup dairy farmer Garry Haddon, the Department of Water and Environmental Regulation and Iluka Resources is exploring how the soil amendment product Iron Man Gypsum (IMG) might be used on farm paddocks to reduce phosphorus loss to waterways from sandy soils.
IMG holds phosphorus, keeping it within the soil rather than washing into local waterways where it can contribute to water quality problems like algal blooms.
The Department of Water and Environmental Regulation lead scientist Dr Brad Degans said the effectiveness of IMG in reducing nutrient leaching from turf farms and grass pastures has been previously proven, but this is the first large scale trial of the product on an active dairy farm.
“The 5.2 hectare site of the trial has been grazed for many decades and was previously fertilised, leaving a high phosphorus content in the sandy soils.
“Without treatment the paddock would continue to lose phosphorus into local waterways, even though this nutrient is no longer being applied as a fertiliser.”
Dairy Farmer Garry Haddon said he was looking forward to the trial results.
“I’d like to get ahead of the game in terms of managing nutrients from our dairy.
“I have a young son who may like to try his hand at farming one day, so we are keen to do what we can to make sure he can also have his chance.”
Monitoring stations called lysimeters collect water samples from beneath the surface of the ground to track how effective the soil amendment treatment is at reducing phosphorus leaching.
Changes to nutrients levels in run off and shallow groundwater are also measured as part of the trial, as well as assessments of pasture production and nutrient uptake.
The trial at Yoongi Farm is the largest of four soil amendment trials being undertaken across different land uses as part of the Revitalising Geographe Waterways program.