Beneath the surface with David Law Forward Farming

Forward-thinking New Zealand farmers might consider themselves on a learning journey at the moment, as they find themselves questioning the status quo and the way they have farmed for decades.

And there is plenty to question, because the way we’ve ‘always farmed’ is not necessarily the right way.

But there is also a need to question whether widely-held beliefs around particular ways of farming are true, or false.

Recently, a keen follower of Total Replacement Therapy questioned whether we had considered that the amount of clover growing on our Whakatane demonstration farm was, in itself, the source of nitrogen leaching.

He referenced a Lincoln University study that observed an organic dairy farm, no less, had been leaching large amounts of nitrogen through their abundance of clover.

There are several things wrong with this study; the first being that the academics assumed an ‘organic’ farm was the epitome of healthy farming.

I would suggest there is far more to a healthy farm than a title of ‘organic’. Soil quality is not a prerequisite to becoming organic. Rather, organics is more to do with not using chemical fertiliser, weed sprays or antibiotics. You can put no fertiliser on and be registered organic.

So, if this organic farm was leaching excessive nitrogen because of its clover, then I would guarantee the farm in question had depleted soils, no biology, and shallow pasture roots.

It is important to revisit what causes leaching – or rather, what prevents leaching.

The whole concept behind riparian plantings 3m-5m from waterways is that they reduce leaching by 35 per cent, because the plants’ long root systems capture excess nutrients.

Similarly, a healthy biological system, with healthy soil, promotes a long root system not only in plantings and crops, but in any pasture.

We have measured pasture roots of 800mm on a biological farm, which is a far cry from the measurements of 100mm we generally find in a chemical system.

So, what our keen follower is suggesting just doesn’t make sense – unless the whole concept of riparian planting is flawed as well.

However, we welcome all questions, criticism and commentary as it means we are always testing our findings and research against others’ observations, and outdated trial work.

Certainly, the absence of clover in your pasture is a red flag. Clover is generally a sign of a healthy soil, but clover grown in a biological system will have long roots and, as a result, capture excess nutrients and reduce leaching. Total Replacement Therapy is setting out to prove this.

We also have to take into account the amount of liquid fertiliser that is being applied, and what happens to it after application.

A liquid fertiliser is a good soil enhancer when you have healthy soil, but if you only use liquid fertiliser as a foliar feeder the soil will, over three-five years, become depleted of microbes and nutrients.

Adhering to the Albrecht/Kinsey system, we follow the concept that we feed the soil, and let the soil feed the plant.