We are very pleased to be the recipient of another round of Northern Agriculture Catchments Council’s (NACC’s) Farm Demonstration Grants Scheme. The 2016 poultry litter biochar trials is our third successful application and it’s great to see our local NRM group supporting farmers in the Northern Ag Region doing their own research.
2015 Biochar Trials
Last year we ran a similar trial through the program on Jib JIb Farm in Northampton. The initial aim of the trial was to see if there was a potash response to the application of wheat straw biochar in a wheat crop. JIb Jib was chosen because of its low potassium responsive soils.
On their website, CSBP state that “Straw contains an average of one percent potassium (K), so if you remove two tonnes per hectare of straw from a paddock, that removes 20 kg K/ha. To replace that potassium would require an application of 40 kg /ha Muriate of Potash”.
Our own research is showing that when you process a material into biochar, it concentrates the nutrients. We thought that by harvesting the straw and processing it into biochar, we could potentially “mine” potassium from soil types high in it and move it (through the char) to soil types low in potash.
Unfortunately, when we processed the wheat straw into biochar and tested it, we still found quite low amounts of potassium (0.85%), (NB: This was only one test). Interesting, a poultry litter biochar has approx. 2.8% K and a wheat straw/poultry litter biochar blend has 3.18% K.
When you take into account the costs of collecting the straw, transportation and processing into biochar, it soon becomes clear that applying MOP is still the most economical practice to replace potassium.
However, we are yet to understand the co-benefits of applying biochar to soils and this need to be better understood to fully gain an appreciation of the real value. However, once we realised that applying biochar to replace potash is currently nonviable, our attention shifted to the benefits of blending a biochar with fertilisers.
Australian Biochar Research
Research conducted by the South Australian No Till Farmers Association (SANTFA) is showing an increase in fertiliser efficiency when biochar is blended at low rates with traditional fertilisers and banded under the seed. You can find more information on the work SANTFA has done with biochar here. We wanted to see if we could get similar results on soil types in the Northern Wheatbelt.
The trial was seeded on the 30th April with 80 kg of Magenta wheat. Emergence was good however, the dry spell in late May/June caused the plants to run up. This impacted the potential yield of the various treatments severely. Tissue tests were taken during the season and the trials were harvested on the 30/10/2015.
Overall there was no significant difference between any of the treatments in terms of yield, grain weight, protein and screenings. The control (no fertiliser) yielded 1.46t/ha and returned the highest gross margin at $379/ha. Nutrient levels in the soil were sufficient and not a contributing factor in determining yields in this location for the 2015 season.
Treatment 11 – 100kg of wheat straw biochar + 110kg of Agras was the highest yielding biochar/fertiliser treatment which yielded 1.56t/ha with a gross margin of $307/ha. This is something that could be explored further however, the cost and logistics of collection and processing wheat straw into biochar makes this uneconomical at this stage.
Treatment 4 – 55kg of Ktill plus and 35kg of biochar yielded 1.48t.ha and returned the second highest gross margin at $341/ha This is consistent with SANTFA results however, as much as we like this, we cannot base any assumptions considering the rest of the results.
While there were no significant standouts in the tissue tests, it was interesting to see that Treatment 4 had the same amount of P as Treatment 12 -110kg of Agras Extra and 30kg of MOP banded. It has been reported that biochar can release soil bound P, at half the cost for a similar yield this could be investigated further.
A trial of this nature needs to be continued over a long period of time. There is evidence that the benefits of biochar are not seen in the first year of application and that continued applications over a number of years see the best results. That being said, we applied and were successful in another round of the NACC funding.
We designed the 2016 trials to ensure that we placed the new treatments on the old plots. Therefore, the control would continue to have no fertiliser and those treatments with biochar, would receive similar amounts as the year before, thereby building the amount of biochar in those particular plots.
Unfortunately, a farm worker accidentally went into the paddock and worked it up a day before we were due to seed the trials. This was disappointing, as it meant that we could not be sure where exactly the 2015 treatments were. After discussions with NACC we decided the change the trial site to a new location.
The trials were seeded on the 27th April. 80kg of Magenta was sown. Treatments include:
- Treatment 1 Control – No fertiliser
- Treatment 2 Farmer Treatment – 110kg Ktill Plus
- Treatment 3 Farmer treatment plus 35kg biochar
- Treatment 4 Farmer treatment plus 70kg biochar
- Treatment 5 50% Farmer Treatment plus 35kg biochar
- Treatment 6 50% Farmer Treatment plus 70kg biochar
- Treatment 7 50% Farmer Treatment
We aim to keep this trial going for a number of years and will keep you updated on its progress, we will be holding a field walk as part of our obligation to NACC’s program, so watch this space for details.
We are also interested expanding these trials over the wheatbelt. If you or your grower group is interested in working with us to trial biochar in your area, please contact us.