The Feds say: Search for facts the right approach

Elizabeth McGruddy.

Federated Farmers is staunch on the importance of good evidence. If we have a good grip on the size and shape of the problem, we are in with a fighting chance of sorting it efficiently.

Policies impacting the farming sector have too often rested on shaky foundations.

A few skinny bits of data sloshed together with a lot of assumptions.

The good news is some very good work is now coming out of research agencies such as NIWA (water) and LandcareResearch (soils).

To give an example, NIWA has just completed an analysis of algae hotspots for Horizons Regional Council. Algae is the weed we see in rivers - some is a good thing, too much is not.

Ten years ago, Horizons had hardly any algae data. Not to be deterred, the models said the way to fix it was to crack down on nitrogen from dairy farms.

Today, Horizons have the best algae data in New Zealand and the results are not quite what the models predicted.

Across the region, about 80per cent of sites are graded good or excellent. Just four are judged poor: two downstream of urban sewage discharges and two in dry hill country east of Pahiatua.

The learning curve for other regions is simple: get quality data first.

The next example is even more fundamental. LandcareResearch has just secured funding to dig holes to see what happens when the rain falls. on the ground.

It can either run off, be absorbed in the soil, or dribble out the bottom. Understanding what portion goes where is fundamental to understanding such things as aquifer recharge and nitrogen leaching.

But wait, you say, we already have models to predict leaching and recharge. Yes, but they are based on a very small sample.

The rest is assumptions and extrapolations. All credit to NIWA and LandcareResearch: keep it coming.

- Elizabeth McGruddy is a senior policy adviser for Federated Farmers