The use of the Overseer model as a regulatory tool has long been questioned by farmers and scientists. The government has tasked regional councils with the job of regulating nutrient losses to water, but nutrient losses are notoriously difficult to measure or even estimate. The Overseer model however existed, was already used by the industry - and produced estimates of leaching losses. Actual numbers, in black and white. Just what the councils needed.
Farming is the management of complex biological systems, systems we do not fully understand. Agricultural science is the process of trying to understand those systems better, little by little. But there is much we still do not know. The most exciting science is when you have an interesting observation, and try to figure out what is behind it. The mystery of the missing smell Several years ago I was approached by a dairy farmer who had been applying extremely low rates of N fertiliser, yet achieving levels of production per hectare that were equivalent to high input conventional farms.