Trial crop avoids frost with new carbon fertiliser
3 October, 2019
Pictured (on right) shows the barley crop in the trial at Beaumont, near Esperance, that has been affected by frost, compared with the same crop (on left) that has been sown with the new C33 carbon fertiliser pellet from Carbon Ag and appears largely unaffected by frost.
IN a frost-hit cropping region, if you look over a fence into a paddock showing areas of crop appearing unaffected by frost, you know it’s going to quickly capture attention.
This is exactly what has happened at ‘Yupiri’, the property operated by Viridis Ag at Beaumont, near Esperance, that is hosting an extensive trial of a new carbon fertiliser pellet that can be direct-sown through growers’ seeding systems. And the industry will be able to view the trial at a special field walk to be held at the site on Thursday, October 17 from 2pm.
Developed by Carbon Ag and branded C33, the carbon-rich fertiliser contains 33 per cent carbon, more than 45pc organic matter and a balance of other nutrients including nitrogen, phosphorus, potassium, sulphur, copper, zinc, manganese, magnesium and calcium.
Some of the treatments in the trial at ‘Yupiri’, which is set over about 50 hectares of sandplain soils sown to barley, include the addition of the carbon fertiliser pellet to normal and reduced crop nutrition, application of the carbon fertiliser alone, as well as areas where no fertiliser has been applied.
Dr Peter Keating, Managing Director of Perth-based analytical research business, Bioscience, which has been interpreting leaf and soil analysis results from the trial, said it was understood several treatments at the site with normal crop nutrition experienced severe frost damage and this was in stark contrast to treatments with the carbon fertiliser pellet.
“From the images of the frosted treatments, it looked like you would write-off the crop, but there was a major difference where the pellet was applied,’’ Peter said.
He said leaf tissue analysis from the site had consistently shown increased potassium uptake with the carbon fertiliser treatments, as well as higher nitrogen and phosphorus uptake.
Potassium uptake was up to 36 per cent higher than the average level from across the treatments with normal crop nutrition, while phosphorus uptake was up to 38pc higher than the average.
“Potassium has a high osmotic coefficient and so provides a much bigger osmotic effect in plants, while higher phosphorus is understood to help resist frost better,’’ Peter said.
“The phosphorus is helping to develop bigger plants to cope with stress and the increased potassium effectively means there is more anti-freeze in the plants.’’
Soil analysis has shown up to double the level of soil carbon in the rhizosphere, even at the lower pellet application rate of 50 kilograms/ha, and which has also been attributed to greater root exudation resulting from higher plant sugar content.
“The extra carbon from an application of 50kg/ha is not much different to what’s already in the soil, but it’s placing it next to the seed that is helping plants punch above their weight,’’ Peter said.
“Bigger and healthier plants are growing better and the higher sugar is likely having an osmotic effect, depressing the freezing point in plants.’’
He said for every 1pc of soil carbon, generally it can be multiplied by four in relation to moisture holding capacity and the carbon pellets hold three times their volume in water.
“The extra soil organic matter retains more moisture and this is better at conducting heat than dry soil and it radiates up to the top of the plants, which also helps against frost.’’
Dafydd Jones, who has been managing ‘Yupiri’ the last four months and has worked in the region the past four to five years, said about 50pc of the property’s cereal crops were hit by frost.
“A lot of the wheat is stem-frosted, so it could be severe, and the barley was hit during flowering,’’ Dafydd said.
“It has been affected and there is some differences in the trial. Visually, you can see the difference with the crop and the trial is going to be interesting to see.’’
Agricultural agronomist and adviser HF De Wet, Meag Soil Consultancy, who is also coordinating a series of fully replicated trials with the C33 carbon pellet near New Norcia, Tammin, Kulin and Pingrup, said recent sap analysis had generally confirmed earlier leaf tissue results, indicating higher nutrient uptake in the carbon fertiliser treatments.
In addition to the trial at Beaumont and another site near Binnu in the northern wheatbelt, the trials are part of a three-year research program and involve a range of crops including wheat, barley, canola, export oaten hay and lupins.
Applications in the trials include the normal crop nutrition applied at the properties plus half of the nutrition, and with each of these treatments receiving the carbon fertiliser pellet at 50kg/ha and 100kg/ha. All treatments also have received the same post-seeding nutrition and pesticides throughout the season.
HF said root development analysis in the trials, including the root to shoot ratio, also had shown more roots in relation to shoots where the carbon fertiliser had been applied.
“With a higher root surface area, there is more root – soil interaction, resulting in a higher rate of nutrient and water uptake,’’ HF said.
“From general observations, there is increased uptake of nitrogen, phosphorus, potassium and trace elements like zinc and manganese. Another function of a root system is to feed the soil biology carbohydrates produced by photosynthesis. Hence a plant with a bigger root system has the opportunity to exude more sugars into the soil, stimulating biological activity.’’
Final yields, grain quality and return on investment will be assessed across all trials at harvest.
The carbon fertiliser pellet also will be available in granule form for growers next season, while other soil amendment products in the Carbon Ag range include the use of lime, gypsum and trace elements, as well as liquid fertilisers.