Liquid fertiliser, carbon trials raising interest
Brad Wisewould, Carbon Ag, takes growers through the company’s DKP liquid fertiliser, C33 carbon pellet and foliar nutrition trial at Mic Fels’ property at Neridup, near Esperance, recently.
The Neridup grower group pictured inspecting the Carbon Ag DKP liquid fertiliser, C33 carbon pellet and foliar nutrition trial at Mic Fels’ property near Esperance.
TRIALS of a high concentrate liquid phosphorus and potassium fertiliser banded with seed at sowing, together with a carbon pellet drilled underneath and followed by a foliar-focused nutrition program, are creating interesting discussion at spring field walks, particularly considering the rising cost of granular seeding fertilisers.
Ongoing trials of the DKP liquid fertiliser (to be rebranded PowerPK in 2022), C33 carbon pellet and combination of foliar nutrition treatments are being coordinated by Carbon Ag. The company has engaged independent research business, SLR, to conduct fully replicated plot trials at Latham, York and Quairading, while South East Agronomy Research is managing a similar trial on Mic Fels’ property at Neridup, near Esperance.
The treatments at Esperance included three different rates of the C33 carbon pellet (30, 50 and 70kg/ha) blended with urea and banded below the seed, while the foliar applications included DKP, trace elements and a biostimulant product. These were compared alongside untreated plots and traditional crop nutrition, with all trial applications supplying similar nutrient levels. Trial treatments also received two streamed-on applications of liquid nitrogen.
Rob Hughes, South East Agronomy Research, said he started to see differences between the plots at the potassium-hungry, grey sand site at Neridup when “tidying-up’’ the trial prior to field walks recently.
He said Mic Fels and Luke Marquis, South East Agronomy Research, also noted crop advancements in the C33 carbon pellet plots several weeks ago.
“They could pick the bulk and greenness with these plots compared to where no carbon was applied,’’ Rob said.
The local Neridup grower group visited the trial recently and identified the plots with 50kg/ha of the C33 carbon pellet, together with the banded DKP and following foliar nutrition applications, as the most impressive treatments at the site.
Soil types at the Latham, York and Quairading sites ranged from sandplain, which also had been deep ripped two years ago and followed lupins in 2020, through to white gum gravel country with a high phosphorus buffering index (PBI).
Similar DKP, C33 carbon pellet and foliar nutrition treatments, the latter also including liquid nitrogen, were conducted at these sites.
Byron Milne, SLR, said the trials were showing some good differences between the applications, which was expected to reveal some strong data and they were looking forward to the results at the end of the season.
Dylan Hirsch, who is hosting the Latham trial, said he had a keen interest in the treatments and while he only had a single line liquid system on his seeder this year, he was looking to upgrade to a dual line for next season to further experiment with the DKP liquid fertiliser.
“We saw early vigour differences with DKP last year, so we are very keen to see the results this season,’’ he said.
Brad Wisewould, Carbon Ag, said DKP was chloride and sodium free, allowing it to be banded at 10 litres per hectare with seed in the trials.
“It is immediately available and effectively provides two units of phosphorus and five units of potassium,’’ Brad said.
He said it allowed growers to supply the same phosphorus and potassium nutrition at seeding with a reduced volume of compound fertiliser.
“This results in fewer seeding fills and amounted to a 22 per cent productivity gain at seeding for one grower. They delivered the same units of P and K, just that some was in liquid form and the balance from the compound fertiliser.’’
“Growers have then been applying liquid nitrogen either under the seed or with the seed, depending on their seeding system and crop type.’’
Brad said the C33 carbon pellet would be available in granule form for the 2022 season, allowing growers to have it blended with their compound fertiliser to avoid blending on-farm.
“It will be a similar granule size to single super. Growers will be able to use it with their compound fertiliser program, or, if they have a triple bin airseeder, they could apply it separately.’’
He said Veris mapping technologies had identified in recent years that crops cannot gain all available soil nutrition due to physical and chemical constraints, hence the strong foliar nutrition program to fully supply plant requirements.
“Where moisture is not a limiting factor, the foliar program ensures plants are supplied with what they otherwise may not be due to soil constraints.’’
Brad said a grower recently calculated that only 60kg/ha extra wheat yield was required to account for the foliar nutrition investment, applied with liquid nitrogen.