Dirty Rotten Claypans 1: The Quest for Fertility

On the day we met Muntanui's previous owner (a farmer from way back), I asked him if he'd ever had the soil tested. "No need," he said. "It's typical New Zealand soil: acidic and low in phosphorus."

On each successive visit, as I observed and learned more, I began to see the evidence of his assessment for myself. The weeds that favour damp and acidic soils were everywhere: sorrel, dock and plantain. One of the paddocks had serious issues with bracken, another acid lover (but also a useful pioneer plant and nitrogen fixer, revegetating degraded land.) Creeping buttercup through the vegie garden warned us our drainage was bad. And for every five holes we dug, we were lucky if we found one worm.

But it wasn't all bad. Honestly. Sure, our soil is basically a mixture of clay and shale over a hardpan. Yes, it's a bit uncouth and rough around the edges and you wouldn't be too thrilled about it marrying your daughter... but it has promise. I found just enough fertility indicators (clover, chickweed and blackberry) to hint at the possibility that one day -- maybe in less than five years -- our dirt will be black, deep and full of life. Then we'll grow the sort of tucker that gives us superpowers.

Hmmm... are we inspired yet?

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To kick off our epic soil remediation process, I had a wee chat with the Librarian Who Lives In My Head:

-- What soil amendments regulate acidity? Acceptable organic and permaculture solutions only, please.
-- Lime, dolomite or wood ash and lots of organic matter.
-- What about phosphorus deficiency?
-- A passel of chooks should do the trick.
-- That's fine for the vegie garden and maybe the orchard but what about the paddocks?
-- Dunno, mate. Green manures? Pasture cropping? Strip grazing? Fukuoka-style seed balling? More animals? All of the above? Read more books or talk to someone who's already doing it. I'm off for my pedicure.
-- Pedicure? But I always thought you were a bloke.
-- Yeah? So?
-- Feeling awkward now.

That was in October 2009. I had the beginnings of a plan but it would be March 2010 before we were able to get back to Muntanui. When we returned, I learned one of the most important lessons associated with trying to live and farm sustainably: somewhere along the line, you'll be forced to make compromises...

Resources
NZ soil types: Landcare Research
NZ weeds: Massey University's weed database
Weeds as soil indicators: Woodrow, L., The Permaculture Home Garden, Penguin, Australia, 1995, pp 49-51. There's also a good general reference here: http://oregonbd.org/Class/weeds.htm

For an overview of weeds and the services they perform in soil building, check out Weeds, Guardians of the Soil by Joseph A. Cocannouer. Originally published in 1950, nearly 30 years before Mollison and Holmgren's definitive Permaculture One hit the scene, this delightful little book was something of a trail-blazer. It refers to the ability of weeds to stabilise soil and "mine" nutrients, and advocates their controlled use to benefit agriculture. Although written for a US readership, there's plenty that's relevant anywhere in the world. The link will take you to a free online library. It's definitely worth a look.

 - Posted by Farmer Nik