Calingiri farm benefits from soil carbon fix

And that was with less than half the usual rainfall during the growing season.

OSC or Organic Soil Conditioner is a cost effective replacement for soil carbon made from recycled organic matter which has been separated from household waste and composted to Australian standards.

Picken is based on composted straw and pig manure with OSC added to improve soil carbon levels.

Both products have nutrient and water-holding benefits and are guaranteed weed and disease free.

Mr King started using compost for the first time this year and was very pleased with the results.

“Things are looking pretty good considering the season we’ve had,” he said.

“It’s the driest I’ve ever seen it, so we’re doing quite well compared to others around the State.”

The King’s 3500 hectare farm is planted with 2500ha crop – 1500ha wheat, 400ha barley, 300ha lupins and 260ha canola.

A total of 40ha of Magenta wheat had the compost applied – 10ha with OSC and 30ha with Picken.

“We’re rebuilding soil so it can hold water instead of it leaching through,” Mr King said.

A multispreader was used to apply the compost separately in March at 20m3/ha before being dug in with a Cultitrash seeder just before seeding.

The OSC was also applied with 120kg of a nitrogen (N), phosphorus and sulphur fertiliser with small amounts of copper and zinc and 60 litres of liquid N at seeding followed by a 20 litres liquid N topdressing at tillering.

While there were gravelly loams and heavy soils on parts of the farm, Mr King targeted a variety of weak sandy unproductive patches on which to test the compost products.

“Previously nothing grew on there and if it did, it wasn’t worth harvesting,” he said.

One part was virgin country where they had never bothered to seed before.

“I can guarantee if we didn’t have it there, we wouldn’t have anything,” Mr King said.

Mr King said it was hard to tell if there was any difference between Picken and OSC because the soils varied so much, but the growth of the crop had improved yield-wise.

“Where we put the OSC, the crop’s a lot better,” he said.

“I’ve noticed it’s got better root establishment which is about 200mm deep compared to 50mm where it hasn’t been applied.

“It’s helped the crop get its roots into the moisture which was deeper down because there was less rain.

“One Picken paddock has gutless sand so it has improved, but it’s not as good as the others.

“We’ve probably gone from 0.5t/ha to 0.9t/ha on the bad patch.

“Other paddocks have a bit of clay too, therefore it’s hard to tell but we’ve probably gone from 1.5t/ha to 1.7 to 1.8t/ha.

“I presume the crop will improve next year because of the organic matter getting back into the soil and improving the standard.”

Custom Composts business development manager David Sharp said OSC and Picken were a fast way of building up the soil’s organic matter.

“If organic matter improves, soil can hold fertiliser in the root zone more readily, and it provides the right environment for the soil microbes to flourish,” he said.

“It works together with fertiliser but you can use less fertiliser and still have a healthier stronger crop that can withstand dry.”

He said the products had a residual effect and probably lasted two to three years before needing to be topped up.

Trials on these products started five years ago in a variety of locations.

Independent agronomist Deb Archdeacon said tests using the same OSC application rate as Mr King, showed potassium was significantly increased in the leaf.

“One of the most expensive inputs is potassium and sufficient levels in the plant reduce pest and disease pressures and plant lodging, thus producing a stronger and healthier plant,” she said.

“If you’re building more resilience into the crop, you’re reducing your risk.”

Trials also found that as a result of compost being applied, extra nitrogen moved into the plant around the booting stage which could make a difference to the price obtained for the improved grain.

Ms Archdeacon said that soil’s water-holding capacity also increased by 30 per cent in the crop row in the trial.

“The products work better in a minimum till environment,” she said.

OSC and Picken are provided in bulk.

OSC can be obtained for a loading fee of $2.50/m3 where one tonne is equivalent to 2m3.

“Farmers can pick it up themselves if they have big enough trucks, or we can deliver in a 100m3 roadtrain,” Mr Sharp said.

“Farmers can cart their grain up and backload the compost.

“The loading pit has a weighbridge and the minimum load is 25t or 50m3 as it is not feasible to load less.”

OSC can be stockpiled on farms until needed.

Picken costs a little more at $20/m3 because of the added cost of blending manure and composting but it further reduced the need for fertiliser.

Mr Sharp said Picken could be delivered in minimum loads of 40m3 up to a maximum load of 80m3.

“The investment in applying compost is repaid in many ways,” he said.

“We’re offsetting input costs by building up soil carbon and using soil biology to improve nutrient cycling and tolerance to drought and disease.

“Ideally, you would have an ongoing program to maintain organic matter in the soil.”

Mr King said he would keep trialling the products in 40ha plots and would eventually try to cover everything.

“It definitely works,” he said.