Episode 225. Compost, Is it Really Necessary?

This is the World Organic News for the week ending 3rd of  August 2020.

Jon Moore reporting!

Decarbonise the air, recarbonise the soil!

I’m just going to say it: I think the time and effort required to make compost is wasted.

Email complaints to: podcast@worldorganicnews.com 

Let me explain. Over the past twelve months I’ve been setting up a market garden at work, a disability service. We were fortunate to have been donated some spent mushroom compost and this was great for ten no-dig raised beds. There was enough over for about 200 m2 to put in sweet corn but this still left 800 m2 without compost or any other organic matter to be added to the soil.

At home I use ducks to graze, a couple of pigs to follow on and chooks to finish off the garden beds. I think manures are far more useful than compost. I know people who swear by the stuff but oh, the messing about. The collection of material, the stacking, the turning and on and on. The other thing that grates with compost is its lack of a correlate in Nature. 

Nature mulches, in layers. I try to garden by the same principle. I know I’ve shown people how to create no-dig beds with compost and they work but they just don’t sit well with me. 

Given that plants and animals evolved together, I try to ensure their interaction continues in my systems. Finding a way to bring mulching and animals together has, I’ve come to realise of late, been the driving force behind the gardening I do. Way back at the start of the millenium I was living in a periurban area that backed onto a state forest. I started to notice areas of the pasture, within about ten metres of the tree line, were being turned over, scratched up and basically disturbed. I also noticed that the same area was not being affected each night and the areas so disturbed grew back much stronger than the surrounding pasture.

While out walking the paddocks one night I heard a sound which pricked at an ancient part of my humanity. It was the grunting of pigs. Now the keeping of pigs in this area was prohibited as it was a catchment for Sydney’s water supply. This meant I could only have heard feral pigs. That awakened ancient part of my humanity had me back up the hill and indoors in double quick time. These pigs were the cause of the disturbed pastures and their regrowth in an improved way.

Now feral pigs are not ideal. They, in huge numbers, destroy much pasture, waterways, wetlands and other native habitat. They are also the perfect host for exotic diseases. We have neither foot and mouth nor rabies in Australia but if the biosecurity is breached, these feral pigs represent a huge reservoir of potential vectors. Current best estimates have feral pig numbers around 24 million on the mainland. Ferals are not useful in gardening.

I would maintain though that animals, able to express their “animal-ness” are essential. As such we are introducing chicken tractors to the space at work. This Spring they will move across the spaces we are extending into this Summer. The trick will be to balance the “grazing” pressure with the health of the soil and follow the birds quickly with green manures. My favourite “go to” green manure for the past few years has been broad beans. 

I’ve planted so many I can now use them as a proxy for the health of the soil. If their growth is restricted, stunty and so on the soil needs more organic matter. Slashing the beans and leaving them as a mulch is the quickest way to get this material into the soil I know of that doesn’t involve grazing.  

James Ruse, link in the show notes, was given the first land grant under British colonial rule in old Sydney Town. Stay with me! He found the land so poor for wheat production he ploughed the first six or seven crops back in to build up fertility. Now I’m not a plough kind of person but slashing a cover crop of broad beans does the same job with far less labour and paradoxically, much quicker results. Regenerative grazing would work too but we are yet to set up the chicken tractor and I’d rather have something growing. I find it difficult to leave soil bare nowadays.

I do understand that layering on compost would work just as well but the organic matter to build the pile has to come from somewhere. I think, from my observations, that leaving the beans to rot down is better, overall than removing them to form part of a compost pile and then returning that to the soil. I’m open to arguments either way but that’s where I sit currently.

To add another layer to this thinking, I’m going to plant bush peas, Massey is the variety, in alternate rows with the sweet corn this Summer. The thinking is that the peas will fix nitrogen, cover the soil and provide a living mulch and the corn plants will grow through them without much difficulty. Climbing peas I would think prove to be a problem with smothering so I’m going with the Massey variety. As I type this, I’m even leaning towards testing 10% of the field with broad beans rather than the peas. We will see.

Compost then is great stuff. It improves soil, plants love it, you can grow straight in it. It does take time to make, it does take material to make. It involves physical labour and it does not occur naturally. Cover crops, improve the soil by photosynthesising as they grow. They improve soil structure as their roots die off and leave spaces and organic matter in the soil. When slashed they provide mulch to cover the soil and the slashing might well release chemicals that trigger other plants to grow more quickly, at a hormonal level. This is something I’ve only just stumbled upon and haven’t read widely on so I’ll just leave it there as a possible bonus of cover cropping until I can report back to you all one way or the other. There are, Horatio, more things in Heaven and on Earth than are dreamt of in our philosophies, to misquote the bard.

Let’s put in the ground work now, we can all change the world, even if its only a little bit to start with, we will begin the process of: 

Decarbonising the air, recarbonising the soil!

Thank you all for listening and I’ll be back next week.

~~~~

LINKS

Growing a No-Dig Garden on Udemy

Or copy and paste this link:

https://www.udemy.com/course/no-dig-garden-course/?referralCode=7393F372D1748E4A4282

World Organic News

email: podcast@worldorganicnews.com

James Ruse

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