Monday, 19 August 2013


Kiwi farmers are making good progress in developing so-called biological farming ('BioAg') methods for our unique & wonderful land. As the name indicates, this involves a focus on biological life in the soil. The physical and chemical properties of the soil are of course also considered, indeed they are the starting point for soil fertility, but beneficial biological life can enhance their contribution to the plant.

As a mere social scientist, I have limited knowledge of how this works. Lynne and I are just enthusiastic amateurs trying to pick up the science as we go though we do have skin the the game. We are actively heading down this path, helped along by friends and acquaintances alike. 

Because it makes sense. You only need a nodding acquaintance with Mycorriza to want lots of them in your soil. So its not hard to imagine that there might be many other useful bacteria & fungi that aid soil fertility and plant growth. It seems that beneficial soil biology can give plants access to minerals (nutrients) that are otherwise locked up and unavailable. In effect, biological farmers are trying to recruit billions of tiny subterranean critters (worms, microbes, bacteria, fungi etc) to help plants get what they need.

What does all this mean in practice?
All farmers do it differently but there seem to be two common elements to BioAg.

First, do no harm: don’t apply stuff to the soil that will kill or weaken your biology. For example, heavy use of urea as a source of nitrogen is avoided because it interferes with proteins and can harm biological life. Biological farmers often use a bit of urea but get most of their N free from the atmosphere, 78% of which is N.

Second: regular foliar feeding with biologically friendly stuff. Liquid fertilisers get taken up rapidly by plants, whose roots then exude stuff that the microbes use. Many BioAg farmers spray finely-ground lime mixed with trace elements, and/or fish and seaweed brews, worm juice, compost tea, and liquefied humates. All other necessary minerals can be mixed in as required. Liquid sprays are a very practical way of correcting trace element deficiencies - these are hard to mix into bulk dry fertiliser, which is why the fert companies are less than keen to sell these essential elements.

The perceived benefits of this approach also vary across biological farmers. I think most would say they're aiming for better quality grass, from which better animal health and human health will flow. I suspect many would add that this is the main driver and the economic outcomes can lie where they fall. Improved profitability also seems possible depending on how farmers manage the middlemen.

Speaking of middlemen, all of this is very challenging for the big fertiliser companies. But lets discuss them some other time.

No comments:

Post a Comment