Episode 211. Science, Biomimicry and Gardening

This is the World Organic News for the week ending 27th of  April 2020.

Jon Moore reporting!

Decarbonise the air, recarbonise the soil!

Given the current whoha we are exposed to of late, I thought it might be a good idea to look at the science behind No-Dig gardening. 

As long time listeners will know, I’m a big fan of biomimicry. This combined with the scientific method – hypothesis, experimentation, data collection and contemplation – allows us to proceed from a solid starting point. As new information is received we can adjust our hypothesis and test again.

The difficulty of working with natural systems is their complexity. At the extremes we have a dichotomy. One paradigm would have us measure everything. This way leads to madness. The other paradigm is the Fukuoka approach. Leave everything to Nature, adjust previous systems until they match Nature. More on this later.

My approach is as follows: Measure what needs to be measured and leave the rest alone. The key is to pick the right things to measure. The most basic would be output. We are trying to get to a harvest, after all. I would also include pests and diseases, water retention and weed levels. 

After our first summer in the gardens at work, I have some preliminary data. Weed levels were extremely low due to the close plantings. Water retention was poor, we are growing in spent mushroom compost and I’ll be adding more organic matter over the winter. Pests were almost nonexistent. Some slugs but not that many. Diseases were confined to some rust on the broad beans due to over watering, maybe and growing them over summer. Output was a little disappointing. Plenty of cucumbers, mini pumpkins, rocket, cress, sweet corn, mountains of sweet corn, beetroot and silverbeet. Less impressive were the tomatoes, still in the ground and starting to produce but the volume is not what I expected. The mini cabbages did not produce at all. The lettuce went ok but bolted way too soon. This may be put down to the hot, dry spell from mid November to mid January. The potatoes succumbed to a fungal infection. We managed to get our seed weight of spuds back but I’ll not plant those. The plan is to grow them under straw in corrugated iron raised beds next Spring.

Armed with this data, I will plant more of what worked, adjust conditions of what didn’t and measure again.

Now as I said earlier, going from an established conventional system to a more biomimicry based on can be problematic. When Fukuoka first applied his ideas to his manadrin orchard, he just left it alone. The orchard though had previously been pruned and by not pruning, leaving things to nature, the orchard was swamped by insect pests as the unpruned branches overgrew each other, weakening the plants and leaving them open to pest attacks. He then began a system of pruning to return the trees to their “natural” shape. Now just what is the natural shape of a manadrin tree? What is the natural shape of any tree for that matter? 

Fukuoka settled on a central leader shape. As the orchard aged, the older trees were replaced by never pruned trees which did, indeed, grow as central leaders. He also replaced one in nine fruit trees with a legume. Acacias in his case. This brought nitrogen to the orchard through the bacteria on the tree roots rather than the need for chemical N. 

The process to biomimicry is fraught. Fukuoka’s other great insight was with grain growing. Having observed winter grasses in the wild growing up through the decayed straw of summer grasses in Autumn and the reverse happening in Spring, he set about to recreate the process in his rice field. Over sowing the field with barley or millet two weeks before rice harvest, he reasoned these winter hardy cereals would grow through the rice straw once it had been harvested, threshed and returned to the field. As he said, he suffered from the Japanese disease of neatness to begin with. He laid the rice straw in tidy, straight lines across the now growing winter cereal. Nothing happened. He’d smothered the winter growth. Next year he distributed the rice straw haphazardly across the growing winter cereal shoots and the system performed as designed.

There’s a couple of lessons from the rice field and the orchard. Just because it doesn’t work the first time and the neighbours are laughing, don’t stop. Nature will teach us if you just observe. The courage to hold to our convictions actually makes a difference, is those convictions are based on good observation.

To that end, in the gardens at work and the new gardens at home, I’ll be moving from a fully intercropped 15 species garden bed to a more nuanced approach. No, not beds upon beds of the same cultivar but beds of mixed species but fewer of them and with more growing space between plants. How this change will affect the weed metric will be a key performance indicator. 

The beds at work are spent mushroom compost over cardboard. Some have been topped with seaweed, some with vermicompost. The roots of harvested plants have been left in the soil as often as possible. More organic matter being the driving principle. In the new beds at home I’ve laid wet cardboard over the sweeping from the chicken house, straw and droppings. Over this I’ve layered seaweed, about 15 to 20 cm, that’s 6 to 8 inches. Over the seaweed is a thicker layer of horse droppings I purchase from a house place down the road. They are good organic types and their stock is healthy so I’m not importing any veterinary medications nor chemical sprays. This layer was originally 15 to 20 cm too. The whole bed has settled and I have another 15 to 20 cm worth  of droppings to add. Over all this I am emptying the accumulated organic matter from the duck drinking buckets. This is lovely stuff. Thick, rich and not too smelly. It gives another organic matter option to the brew that is the garden bed.

I’ll be growing broad beans, wild rocket, cress, silverbeet, carrots, broccoli and beetroot. I’ll report on results as they come through over the next six months or so. We are down to pigs, ducks and chickens at the moment. The pigs are freezer bound and I’ll be replacing both of them with four weaners to get through the rehab of the final half acre in six months rather than the twelve it has taken Jake and Elwood. They have done a great job removing blackberry shoots and roots. The gorse was beyond them but I’ve removed that by hand. I’m looking forward to the new piggies doing a number on the last half acre.

I always try to integrate animals into the garden system. These plants, their wild ancestors anyway, evolved in conjunction with animals. Again, in an attempt at biomimicry, the animals will play a part in the garden. The pigs prepare, the ducks will clean and the chickens provide hot manures to use as the base of a raised bed. Between the soil and the cardboard, the hotness of these manures have time to cool before the roots in the raised bed no-dig garden can reach them.

I would suggest that a thoughtful approach, dear listeners, would have you finding solutions and biomimicry options where you are. I’d love to hear of your successes or just opinions if you have any on this approach.

As I’ve mentioned for the past few episodes, there’s a link to a Udemy course in the show notes entitled “Growing a No-Dig Garden” if you’d like some more formal assistance in your gardening and you can also send people to Episode 207 where I discuss growing a quick response garden to get yours happening swiftly.

Remember in this unusual time, if we put in the ground work now, we can all: 

Decarbonise the air, recarbonise the soil!

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



Growing a No-Dig Garden on Udemy

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