A recent organic oat trial completed by Teagasc found that the use of Supersoil and two other spray-on treatments (Blue N Biostimulant and Tri-Kelp Seaweed Powder) showed no improvement in yield from any of the treatments when compared with a plot which received zero fertiliser.

The trial was conducted in Duncannon, Co Wexford, and compared the three spray treatments to four organic fertiliser sources (dairy processing sludge, organic poultry manure pellets, cattle slurry and free range layers manure pellets), with a control plot left untreated.

Supersoil was spread at a rate of 250g/ha at a cost of €75/ha for the product. Spraying costs came to €25/ha, leaving a net cost of €100/ha.

The use of Super Soil in the organic oats trial resulted in no additional yield and no contribution to P and K levels in comparison to a control plot which received zero fertiliser.

No additional crop yields were recorded in comparison to the untreated plot. The plot grew 3.46t/ha of oats, with a P and K offtake of 12kg and 17kg respectively, with Supersoil supplying zero P and K.

Offtake costs of the P and K were calculated at €73/ha based on crop yield (assuming straw was chopped), leading to a net loss of €178/ha where Supersoil was used compared with using zero fertiliser.

Table 1 shows the overall results from the first year of trials.

Poultry pellets resulted in the largest gain in crop yield, but were also the highest-cost fertiliser used in the trial.

Cattle slurry resulted in the overall highest profitability, with the trial calculated off slurry being received for free with transport and spreading costs of €125/ha.

The yield results of the organic oat trial which was completed by Teagasc in Duncannon, Co Wexford.

It also returned the highest amount of K of any of the trial fertilisers, leaving a net gain of €219/ha.

Dairy sludge recorded the second-highest net gain, though this was based off the cost of the product being nil (product supplied and spread for free).

Dairy sludge was also unable to supply the K offtakes from the oat crop harvested from its trial plot. The above was calculated based off straw supplies from the crops being chopped.

The trial plot was a medium-heavy soil in Duncannon, Co Wexford. Soil fertility pre-trial was recorded as pH6.1, P = 5.6mg/l and K = 97mg/l. This was the first year of the trial, with Teagasc stating that "more data was required".