Ballance Agri-Nutrients Ltd v Ravensdown Fertiliser Co-Op Ltd
(CIV 2009-404-2171, 4th March 2011)
Ballance appealed an unsuccessful opposition to Ravensdown’s (and Lincoln University’s) patent application for a method of applying a nitrification inhibitor to grazed pasture soil so as to reduce nitrate leaching, reduce nitrous oxide emissions and increase pasture production.
Ballance claimed the Assistant Commissioner erred in allowing amendment. In particular, in claims 1 and 18 the phrase “treat the area” was replaced by “to cover substantially the whole of the area”. Ballance asserted that the amendment was not by way of disclaimer, correction or explanation and resulted in a claim of wider scope. However, the Judge held that the amendment was by way of clarification and was allowable on a purposive construction.
The Judge also held that the Assistant Commissioner did not equate the preferred witnesses with the hypothetical skilled addressee. Such a view could only be sustained when the Assistant Commissioners comments were taken out of context. While the skilled addressee will hold academic qualifications in the area of soil chemistry and biology, the Assistant Commissioner was right to identify knowledge of practical farming methods as a necessary attribute.
While the nitrification inhibitor was known to the skilled addressee before the priority date, the Judge held that its application in isolation was not known to have the claimed useful or economic attributes. If anything, the evidence would have pointed away from that. None of the referenced prior art contained all the attributes of the invention. Most notable, they either did not advocate the use of the nitrification inhibitor in isolation, or were not directed at grazed pasture. The pleaded prior use did however involve the application of the nitrification inhibitor in isolation on grazed pasture. However, the method and purpose of a trial was held to be inconsistent with Ravensdown’s method and it found no effect on pasture production. Further, the Judge considered that Ballance had not done enough to show that the trials were not secret or not obvious to other users of the farmland. Similarly, the Judge held that Balance’s evidence was unconvincing and insufficient to support the proposition that the claimed invention was either obvious or worth a try.
Finally, the Judge held that Ravensdown’s new use and new purpose of a known compound qualified as an invention. The claim types are consistent with the Australian NRDC decision ( HCA 67) and European Mobil decision ( EPOR 73), both of which have been affirmed in New Zealand by the Court of Appeal’s Pharmac decision ( 2 NZLR 529), which itself is critical of passing criticisms of the Mobil decision in several UK judgments.