Posted by

Posted on

August 10, 2019

Posted under

compost, Death, Gardening, Permaculture, Recycling, Soil, Waste

Comments

Scientifically hot: in which I fall in love with the Berkeley method of composting

Revenge is a dish best served cold. Particularly when you are seeking revenge against a tree. Given the pace of their lifestyle, you have to drag it out for those guys to really feel it.

So how better to punish a seed-strewing, bat-choking, weedy cocos palm than – not simply chopping it down – but committing it to a doom of eternal proximity to rotting horse shit?

How to torment a cocos palm: shower it with shite

What a red-letter year it has been for composting. The year when I discovered the Berkeley method. It sounds like natural form of contraception and it is hot, but it’s better than that because it works. Time after time after time.

I have thought I had achieved the giddy heights of hot composting before, long ago when Treasure the white Sussex was queen of the chicken run, freaking me out by regularly supping from my vat of compost tea.

The much missed Treasure and her dangerous drinking habits

In those days I was convinced that the way to fast, weed free compost was my trusty tumbler, still the first destination for our kitchen scraps and chookhouse bedding. The tumbler certainly steams when you crack it open to add the week’s potato peel and apple cores, and not just on these winter mornings.

But I guess, like so many other lovely things, you don’t necessarily know whether you’ve really hot-composted, until you actually experience it Then you realise that on all those previous occasions when you thought what you were doing was pretty hot, you were wrong, and in reality it was all distinctly tepid.

Chickens looking for worms in my now-cool heap

Ingredients for my first heap: leaves, ash, straw

First “brown” layer

Layering leaves and manure

Another layer

Covering a pile with palm fronds

So what is the Berkeley method of hot composting and how do you get some of that good stuff?

The Berkeley method involves making a big heap of compost – at least a metre tall and a metre wide – all at once, using layers of high nitrogen (“green”) and high carbon (“brown”) ingredients.

I’ve used a a range of different “browns” – liquidambar and bamboo leaves, pine needles, sugar cane hay from the the chook cage (with its own little payload of nitrogenous ordure) and even cardboard boxes ripped up into small pieces. This is a soothing activity to do in front of television and the only part of compost-making I can get my children have anything to do with).

Berkley method heap 2 featuring lots of bamboo leaves

I usually try to sneak in some partially-rotted “warm” compost from my tumbler as a “green” layer low down in the heap just to keep our household waste systems from being overrun with biomass. As a small household, we don’t really produce enough veggie scraps all at once to create the bulk materials needed for the Berkeley method. Other people use thin layers of lawn clipping but we have chooks so we don’t have any need for lawn mowing. That’s an understatement really – for much of the last three years our backyard has looked like the Somme.

My mainstay for “greens” is, ironically, distinctly brown – vast quantities of equine ordure, acquired at $1 a bag from the horsey country on the other side of the Berowra Waters Ferry. I’m pretty sure my ten or fifteen bucks, left in an honesty box by the front gate, ends up in the pocket of a shovel-fit teenager, which gives me a warm glow. You could get the same amount for free in another farm down the road if you had a trailer and good upper body strength.

It’s a fun weekend outing – I particularly enjoy coming back across on the ferry with the windows down, suffusing the palatial surroundings of the marina and its smattering of Hollywood celebrities with the fruity ambience of a stable.

The always picturesque Berowra Waters Ferry

But if your idea of a good time doesn’t involve intimate encounters with 150 kilos of horse manure, there are other options. Not carnivore poo though. Just in case you happen to live near a zoo and were thinking of a midnight raid for high nitrogen materials, Robert D. Raabe, Professor of Plant Pathology, Berkeley, in his detailed account of hot composting, reminds us that tiger and lion shit are not worth the effort.

In my first few heaps I also added some wood ash after each layer – it‘s high in potassium, can correct acidic soils and since our wood-burner produces loads of it I’m always trying to think of uses for it. There’s also a kind of wedding like gaiety to hurling handfuls of white powder over the mountain of poo which I really enjoy.

I think I got a bit carried away on my last batch of compost, though, as I discovered when my youngest did a science experiment: broad beans growing in three different soil types. My newly made compost was literally off the scale on the Ph test. My vegetables are probably suffering but I suppose at least I now have a convenient lime-rich place for disposing of fresh corpses.

Super-alkaline ash-rich compost

The science experiment in action

Each layer of your heap should be watered as you build it, til the whole thing is about as damp as a squeezed out sponge. If it’s especially wet or hot weather you can cover it to stop it from drying out or getting soaked. As you can see in the piccies above, I roofed my first Berkeley heap with palm fronds, partly to keep my heap from getting too dry and partly just to continue to torment the spirit of the evil tree they were hacked from. None of my subsequent heaps have had a cover, though, and they seemed to turn out just fine.

To be honest, while there are lots of really complicated rules for hot composting – for instance, this article gives a mind bogglingly detailed run down on the carbon-nitrogen ratios of a range of composting materials. But in my experience, a rough and ready mix of about equal quantities of “greens” and “browns” just seems to work.

Then after you’ve built your heap, you just leave it for about five days. All the while you are at work – sitting in meetings, shuffling paper or cruelly inflicting post-structuralist theory on innocent undergraduates – that aerobic bacteria is doing its thing. It’s a curiously comforting thought.

Chooks cleaning up the last few weed seeds

Then you turn your heap. The aim of Berkeley method hot composting is to create a friendly environment for the right kind of bacteria and fungi – the ones that like plenty of air. They work quickly, produce plant nutrients like nitrogen, phosphorus, and magnesium and even smell pretty good (trust me on this). Over the first few days after you build your compost pile, a sequence of different bacteria go to work – first the psychrophilic, then the mesophilic, and finally, once the heap gets to about 37 degrees celcius, the thermophilic. Once the pile gets up to between 55 and 70 degrees, the heat kills off weed seeds and most insects (and some bacteria too). But the thermophilic bacteria quickly use up all the degradable materials unless the heap is turned.

But how do you know if your heap is hot enough? Here’s the advice of one permaculture site: “as an simple guideline. if you can put your arm into the compost up to the elbow, then it is not at 50 degrees Celsius, and is not hot enough”. If the idea of a forearm coated in hot shit doesn’t appeal to you, you can also use a cake thermometer. But perhaps not on the same day as the school bake sale.

I don’t bother with thermometers. After the allotted number of days, I just dig into the guts of the pile. If steam comes pouring out, creating a sort of horse-poo sauna for the shovel wielder, things are cooking. Best not to turn your heap in your PJs or your ballgown,though.

I’m not so sure about white stuff you can see in the picture on the right. According to the University of Illinois‘ composting boffins, this is actinomycetes – “a higher-form bacteria similar to fungi and molds” which feeds on the woody bits in the pile and helps make well cooked compost smell earthy. Robert Raabe, Dr “Afraid of lion poo”, thinks it’s a good sign in hot compost. But it usually turns up in an nonaerobic pile so this pic indicates that while my current heap is hot it probably have been turned a bit earlier.

As the old joke says “What’s the difference between a good gardener and a bad gardener? Two weeks”. Still, with a turn over and a bit of oxygen, I reckon my compost will get back on track. A perfect heap might require that horse do-do up to the elbow but a pretty good heap seems to be manageable without that level of commitment.

My technique for turning the pile is quite primitive – kind of like knocking down a stinky sand castle. I dig into the steaming centre of the pile, shovel the hottest part of the heap to one side (up against the remains of the tortured ex-cocos palm). Eventually the undercooked layer above caves in in a satisfying way. I do that a few times, so the outside part of heap is in the middle, ready to heat up again.

Somtimes when I’m tending my compost heap, I feel like I’m channelling the spirit of a brush turkey dad, as he scratches his big pile of mulch around, keeping the temperature just right for his clutch of eggs.

Brush turkey bloke tending his nest

Having turned your heap, you let the heat build up for a couple of days and then you turn it over it all again. And then again every two days or even once a day if you ever get over-excited. That goes on for about two weeks. The write up of the Berkley method in the University of California’s Vegetable Research and Information Center (my kind of place) stresses that “outdoor exercise is an added benefit” of hot composting.

For a kayaker, all that shovelling is not bad thing at all, leaving aside the fabulous pile of compost you get at the end of the three weeks of relentless digging. It’s hot composting and hopefully you get hotter in the process of making it. Truly, there is no downside.

Some other posts about gardening experiments

My attempts to grow luffa…. no it doesn’t come from the sea!

Night of the living mulch: cover crops for the zombie apocalypse

The ginger family stole my brain!

DIY by subtractions: the kiwifruit arbor

From battery to backyard: the story of our rescue chickens, Dusty, Crumpet and Ruff

Turning our garden into whipbird habitat by making a mess

References

Antonella Anastasi, Giovanna Cristina Varese & Valeria Filipello Marchisio
(2005) Isolation and identification of fungal communities in compost and vermicompost, Mycologia, 97:1, 33-44

Yan Guo, Jinliang Zhang, Changyan Dengand Nengwu Zhu (2012) Spatial Heterogeneity of Bacteria: Evidence from Hot Composts by Culture-independent Analysis Asian-Australian Journal of Animal Science Vol. 25, No. 7 : 1045 – 1054

Posted by

mccnmatt

Posted on

February 19, 2016

Posted under

Anthropomorphism, Geology, national parks, Soil, Uncategorized, waterways

Comments

9 Comments

Alhambra on the Hawkesbury

The last few times I passed by Bujwa Bay, on my way downriver from Berowra Waters, it was shrouded in mist.

On the way to Bujwa Bay

Mist blowing out of Bujwa Bay

A misty morning on Berowra Creek

But last Sunday, in the golden light of late afternoon, there was a revelation.

I’m familiar with the Hawkesbury’s sculpture parks and sandstone art galleries. But the fact that Berowra Creek had well preserved fragments of an ancient Moorish fortress – well, that was news to me.

The “sculpture park” on the northern shore of Long Island, the Hawkesbury

River rainbow, in Berowra Creek

Honeycomb formations in a cave above Bujwa Bay

Sandstone art gallery in Smith’s Creek

When I went home and told RB I’d seen something very like the famous stucco inscriptions of the Alhambra on a estuarine cliffside at the end of Berowra Waters Road, his comment was “You’re barking!”. And he’s probably right.

Honeycomb weathering in sandstone on Bujwa Bay

After all, the Alhambra is an artistic jewel, a masterwork of European Islam, preserved over the centuries after the Moors themselves were driven first into the mountains and then out of Spain altogether. Its delicate carved plasterwork miraculously survived Christian conquerors, dodgy architectural restorers, squatters and tourists. And the sandstone of Bujwa Bay is just, you know, rock.

“The sea” in the Alhambra

Stucco inscriptions

The Alhambra from a distance

Stucco and tile in the Alhambra

Stucco inscription at the Alhambra

But I’ve been reading about “thing power” and it’s given me a whole new angle on inanimate objects. “Thing Power!” – sounds like a killer bathroom cleaner that will sort out all the disturbing life-forms, named and unnameable, in your shower cubicle.

But according to Jane Bennett, its “a creative not-quite-human force capable of producing the new [that] buzzes within the history of the term ‘nature’ ” (2010, 118). Electrons, microbes, minerals, waste, all busily making and shaping things, inside, around, through, against and despite humans and their fancy-pants plans. She reckons things and people rub along or against each other in a pattern that’s “not random or unstructured, but conforms to the strange logic of vortices, spirals and eddies” (2010, 118).

Alveoli weathering in sandstone

Stone lacework on Bujwa Bay

Kooky as it sounds, this is not a bad description of how the Bujwa Bay Alhambra came into the world, according to a paper coauthored, in a way that pleases my penchant for magical thinking, by a geologist from Granada, home of the famous palace.

Honeycomb weathering like this happens in all sorts of porous rocks, around the world – from Antarctica to Jordan – and maybe even on the surface of Mars. It might seem like hollows would form in weaknesses in the rock, but it’s not necessarily so. Blistering heat, frost, chemical weathering and rain are all in the frame – with maybe a little help from the odd patch of algae or lichen. But mostly it’s about salt and wind.

Salty water – in this case from seaspray – seeps into the rock and crystallises, making tiny fractures. If there’s plenty of water, salt crystals forms on the outside surface to form efflorescence, a mineral flowers blooming on a cliffside or a cellar wall or a garden fence. But the real damage is done deep in the rock.

According to Rodriguez and friends, once a depression is formed in the rockface, wind eddies and swirls inside the concave parts of the stone. Faster breezes mean more evaporation and a super-saturated salt solution, meaning more salt crystals and more fretted stone. Eventually the rockface becomes lacework, without any intervention by a rock lacemaker.

Alhambra rocks 1 crop long

The other name for honeycombed rock is alveoli. It’s stone with lungs. Made of mineral flowers. Not alive (or mostly not alive – sorry algae) but doing complicated and beautiful things.

Not immortal, invisible, unfathomable. In fact, as fathomable as the waters of Bujwa Bay at low tide, that is, knee deep to a heron. Just exceedingly hard to grasp.

And that’s not just me banging my head against a corroding brick wall of “Salt weathering: a selective review” – the geologists are still bickering over exactly how it works. In Bennett’s (possibly slightly loopy) words, it’s vital matter, “hard to discern… and, once discerned, hard to keep focused on. It is too close and too fugitive, as much wind as thing” (119). Or perhaps, in this instance, both wind and thing.

A crab wondering what I’m on about, on a beach near Bujwa Bay

References

Jane Bennett 2010 Vibrant Matter, Duke University Press

Eric Doehne (2002) “Salt Weathering: a selective review” from Natural Stone, Weathering Phenomena, Conservation Strategies and Case Studies. Vol 205, 51-64, Geological Society Special Publication

Carlos Rodriguez-Navarro, Eric Doehne,Eduardo Sebastian (1999) Origins of honeycomb weathering: The role of salts and wind, GSA Bulletin; August 1999; v. 111, no. 8; p. 1250–1255

Huinink, H. Pel, L, Kopinga, K. 2004 “Simulating the growth of tafoni” Earth Surface Processes and Landforms 29 1225-33

Posted by

mccnmatt

Posted on

June 23, 2015

Posted under

anthropocene, Geology, History, national parks, natural history, Seasons, Soil

Comments

8 Comments

Midwinter lagoon

Bombah Broadwater in the gloaming

It’s past the shortest day of the year, but, in spite of her scrapes and dings, Egg the elderly wooden kayak doesn’t seem to be ready for drydock yet. Perhaps it’s that last unseasonable whirl of autumnal warmth, caught alongside the coast in the East Australian Current, that’s keeping the sea a balmy 20 degrees. Or perhaps it’s just the lure of still, winter water all around.

Since Egg was first laid in our driveway a year ago, I’ve been seeing Sydney differently. Those long roundabout routes from A to B via M and Q and P, punctuated somewhere along the way by a bridge or two, suddenly make sense. The city of roads and buildings retreats and, I feel, just out of sight on every side, the presence of water.

The Hawkesbury estuary

Upper reaches of Berowra Creek, a hop skip and jump from the Hornsby Westfield

This is our backyard, encircled by the salty embrace of the Hawkesbury estuary. But it doesn’t end here, with the secretive topography of flooded river valleys. All the way up (and down) the New South Wales coast, the shoreline is flanked by coastal lagoons. I’m not complaining, even the tiniest little bit, about all these sheltered waters. But I’ve started to wonder what geographic accident has given a timid canoeist so much to feel grateful for.

Along with marshes and flats, coastal lagoons make up maybe 10% of the world’s seaboards, and in NSW lots of us live by them, many more than by the ocean itself. Lagoons (or wave-dominated estuaries – there are ongoing hissy-fits around these definitions) appear where low-lying plains, rather than dramatic cliffs, meet a shallow gently sloping seabed. Usually, they are found on shores shaped mainly by waves rather than big tides, with underlying rock that crumbles nicely into beach sand not finer, silty sediment.

The more sand the better – perhaps our generous continental shelf harbours this bounty from a time when the Sydney Basin was a enormous braided river delta, like the Ganges today. But you don’t want too much rain – lagoons are usually fed by an underwhelming little creek or even just groundwater – that doesn’t (or doesn’t often) burst through the land between waterway and ocean.

Dawn breaks over the barrier between Bombah Broadwater and the open sea

To make a lagoon*, you need a barrier to the open sea. In the nineteenth and first part of the twentieth century, coastal geomorphologists duked it out over just how these barriers were born. Did breaking waves make for ever-rising off-shore sand bars? Did encroaching seas submerge coastal dunes? And then there’s the third, attractively named “spit accretion theory” (Davis and Fitzgerald, 2004). Not, as it might sound, a creation myth where bunyips drool into puddles between the dunes; just sand clinging to rocky headlands as it is carried along the coast by the (delightfully piratical) longshore drift.

It turns out that everyone was right, at least some of the time. Which is nice. It’s hard to keep the heat in a scientific controversy when lots of the evidence, hidden beneath the surface of the sea in the first place, has been washed away or covered over during the last few millenia by terrestrial silt or aeolian sand. Who could be angry with such mellifluous and frankly otherworldly-sounding geomorphologies in play?

Pelican landing on Bombah Broadwater

Most lagoons have only been around for a little while, geologically speaking, formed after sea levels began to rise as glaciers melted 18,000 years ago or thereabouts. Many, like Narrabeen Lake, which we whizzed round on our bikes in the company of half the population of the North Beaches a few weeks ago, are even younger, not seven thousand years old. A blink of the eye for people who were here 50,000 years before.

Strangely, lagoons move. Today’s surfers walk across the relics of yesterday’s drowned lakes. Barrier beaches migrated landward, emerging from the ocean just as “marine transgressions” (that’s advancing oceans, not the naughtiness of waves) slowed. Shaped in stable times, coastal lakes still don’t hang around for long. This shouldn’t surprise me – I know that, despite appearances, beaches are really rivers of sand.

If the tides were higher, if the rivers was faster or siltier, if Australia wasn’t so seismically serene, the lagoons would fill up and dry out or be washed away, and the cormorants would have to hunt elsewhere. In fact, for all our dredging and draining, it’s happening right now. Like life itself, coastal lagoons are a transitory phenomenon, a passing pleasure.

Surfers floating over the relics of yesterday’s lagoon

Narrabeen Lake

Black swans in Narrabeen Lagoon

(Little?) Black cormorants

Intermediate egret in Narrabeen Lagoon

And then there’s the gyttja, something so very special it’s found nowhere else in Australia, and helps qualify Myall Lakes as a unique protected wetland. What is it? Well, rotting pondweed. No, I’m underselling it: it’s up to 70cm of “a highly mobile and organic mud that has a gelatinous appearance”, a “flocculent green–brown material” (Drew et al 2008), “an uncompacted, anoxic and sulphurous ‘ooze'” made from “the decomposition of charophytes, macrophytes, cyanobacteria and algae”. Strangely, not so much about the ooze in the National Parks brochures. But it’s an ooze that’s been there for, perhaps, a thousand years.

Dusk on Bombah Broadwater

Looking west at dawn on Bombah Broadwater

Canoeists in the gloaming

Eric the Egret on the Bombah Point Ferry

Glorious Angophora

Reflections on the tea-brown waters of Myall Lakes

Still morning on Two Mile Lake

I’ve been thinking about lies beneath the surface of the water and the windblown sand. But paddling through the Broadwater two weeks back, in a startling moment I found myself not gliding above the mysteries of quiet waterways, but surrounded, right amongst it. A huge flock, a murmuration almost, of little black cormorants, perhaps returning from a fishing trip, passed above and on one side and on the other without a single cry but with a sound I’ve never heard before: the white noise of hundreds and hundreds of moving wings.

The sound of the midwinter lagoon, all around me.

Little black cormorants murmurating

* Be warned: there’s a chance my account of the origins of coastal lagoons is completely wrong. After all, the New South Wales coast “has provoked many questions and various degrees of controversy” (Thom, 2010, 1238). And perhaps it’s “premature to attempt a comprehensive analysis of coastal lagoon evolution and dynamics when so many lagoons have been so little studied” (Bird, 1994, 13). In case you want to check my workings:

References

Bird, Erik (1994) “Physically setting and geomorphology of Coastal lagoons” in Kjerfve, B. (ed) Coastal Lagoon Processes, Elsevier
Davis, R. and Fitzgerald, D. (2004) Beaches and Coasts, Blackwell Science
Drew, Simon Iona Flett, Joanne Wilson,Henk Heijnis, C. Gregory Skilbeck (2008) “The trophic history Myall Lakes, NSW, Australia” Hydrobiologia 608
Eyre, Bradley and Damien Maher “Structure and Function of warm temperate east Australian lagoons: implications for natural and anthropogenic changes” Coastal Lagoons: Critical Habitats of Environmental Change, dited by Michael J. Kennish, Hans W. Paerl
Martin, Louis and Jose Maria Landim Dominguez (1994) “Geological history of coastal lagoons” Kjerfve, B. (ed) Coastal Lagoon Processes, Elsevier
Masselink, Gerhard and Hughes, Michael (2003) Introduction to Coastal processes and geomorphology, New York, Oxford University Press
Thom, Bruce, Hesp, Patrick, Bryant, Edward (1994) “Last glacial ‘coastal’ dunes in Eastern Australia and implications for landscape stability during the Last Glacial Maximum” Palaeogeography, Palaeoclimatology, Palaeoecology 111 (3-4)
Thom, Bruce (2010) “New South Wales” Eric Bird (ed) Encyclopaedia of the World’s Coastal Landforms, Springer

Posted by

mccnmatt

Posted on

February 5, 2015

Posted under

Animal pests, Backyard birds, Brush turkeys, Damage caused by chickens, Exclusion pest control, Fruit, Gardening, Plants and what I know about them, Pollination, Soil, Vegetables

Comments

3 Comments

Jailbreak!

“I gotta get outta here!”

Cucumbers will go to desperate lengths to flee an attack-flock of brush turkeys, eh?

“Freedom!” – zucchinis under veggie nets

So is it better to die fighting than live in chains? I’m not sure where my zucchini would stand on this one.

I’ve managed to keep the plants alive under an ancient perforated veggie net, held up by a rusty drum stand and contorted steel reinforcing wire. Shyla the Australorp sneaks through to lay the odd egg but so far the brush turkeys haven’t spotted an entry-point. Which is lucky, because if they made it in, there’s no way they would ever find their way out again. I’d arrive in the garden one morning to find a turkey skeleton splayed out underneath the enormous hole these leaves are bursting through.

The bees don’t seem to have found the great big holes in the netting either. Or perhaps the local pollinators suffer from claustrophobia. I’ve seen loads of male flowers but the little golden zucchinis just seem to wither on the vine. I’m trying to figure out if it’s (a) the plant aborting seedless, non-fertilised fruit (b) blossom end rot, thanks to insufficient calcium (c) rampant powdery mildew, caused by constrained circumstances (d) despair induced by a life Inside or (e) all of the above.

Going, going, gone … doomed baby zucchini

It hasn’t been a good year for jam making, either. Here’s the breba crop which was looking so lovely mid-winter. Not really worth setting aside a day in the kitchen for preserving this one. On the right, “dried figs”, but not as we know them. A few hot days saved me the cost of a dehydrator, but I’m not sure gastronomy is the winner here.

The 2014 breba crop

This is not what I normally think of when someone mentions “dried figs”

And a sad discovery this morning – the lone survivor of my bumper crop of coyly fleshy persimmon flowers ripened, unattended, and was demolished overnight, probably by a young possum taking a leisurely midnight stroll from his summer house above the air conditioner in the granny flat. Only a few days back I was thinking if might be time to wrap the precious persimmon in one of the net exclusion bags sitting neatly folded on the bench in the toolshed.

Persimmon flower retreating from the light

The sad end of an unprotected persimmon

Zero tolerance, it seems, is the only solution. Imprisoning the chickens is mean, imprisoning the possums and the brush turkeys illegal. Whereas imprisoning vegetables, pollination issues aside, seems to work quite well.

Incarcerated lettuce

A new generation of okra seedlings group up under a draining rack

And an older burgundy okra plant, growing through the bars of another tiny prison.

Small scale vegetable prisons seem to do the business for seedlings and your slender or ground hugging plants, but now I have the frame of an aged trampoline at my disposal, I’m thinking big. And I’ve started looking at the superannuated chook tractor with a new eye.

Yes, it has traditionally been Andy Ninja’s lofty sleeping quarters, but with a bit of dusting off, what a fine brush turkey exclusion zone it would make. Perhaps, Andy, it’s time you reconsidered the virtues of Palm Beach, the vernacular modernist architectural masterpiece I painstakingly made you and your feathered friends a year ago, now sadly abandoned by every damn chicken in the flock. Even the brush turkeys don’t try to sleep there.

Now there’s an idea: if the new improved carceral complex with its walk-in prisons doesn’t protect my veggies from assaults by poultry, maybe I should start planting them in the chook house.

Superannuated chicken tractor cum vegetable prison?

Andy Ninja roosting on the chook dome

Andy eyeing up the ex-trampoline, soon to be brush turkey exclusion zone.

Remember Palm Beach, Andy?

Posted by

mccnmatt

Posted on

January 6, 2015

Posted under

Backyard birds, Geology, national parks, Native animals, natural history, Soil, Weather

Comments

4 Comments

In other sandstone country

Ganguddy – a less misleading name than Dunn’s Swamp

Wiradjuri country that is, or Dabee country to be precise: Ganguddy, on the Cudgegong River, that flows west off the Great Dividing Range, not into the Pacific but into the Murray-Darling. Not far from Berowra as the Australian Raven flies – straight across the Wollemi National Park – but a fair trek in the excessively laden ancient vehicle.

Still sandstone though – the older, niftier sandstone of the Narrabeen Group, as it resurfaces at the very edge of the Sydney Basin, with the even older coal measures being mined perilously close by. Layers of ironstone make for fabulous rock formations (if slightly less way out than the famous pagodas of the nearby Gardens of Stone National Park). And of course exceedingly soggy tent groundsheets when big rain sluices off the rocks faster than even sandy soil can soak it up.

Ganguddy

Rock formations

Pagoda

Pagoda lookout

When even sandstone soils can’t absorb the rain

Lakeside sandstone rock formations

Same old sandstone geology, plenty of still water, just like the Hawkesbury estuary down our way, but the critters are different. The feathered food thief at Ganguddy isn’t a brush turkey, it’s the purple swamp hen.

Purple swamp hen posing

Purple swamp hen unperturbed by a flotilla of canoes

Purple swamp hen justifying its name by hanging out in a swamp

Purple swamp hens enjoying the puddles after rain

The “house bird” is a cheeky superb blue wren, not a wattlebird. Rainbow lorikeets – not a one. And none of those aggressive urban generalists, the noisy minors or the magpies, either. Instead crimson rosellas – a rarity in the northern suburbs of Sydney – lurk in implausible locations like the queue for the drop dunny for instance, or the reeds by the river bank.

The ubiquitous but largely invisible bird here isn’t a koel or a channel billed cuckoo but the aptly named clamorous reed warbler. I was at times tempted to nip to the Rylstone Guns and Ammo for a small flame thrower so I could finally get that photograph, but then I reflected that a perfectly focussed snap of a tiny blackened corpse clinging in its rictus to a reed probably wasn’t in the spirit of the thing.

The “house bird”: a male superb blue wren

Crimson rosella waiting impatiently for the drop dunny

The invisible but ubiquitous clamorous reed warbler

Crimson rosella doing unlikely things in the reeds

Little black cormorants watching cricket.

A whiptail wallaby (or “pretty faced” wallaby as fellow kangaroo mafioso prefer to refer to it)

A musk duck. No, it doesn’t have a goitre. It’s meant to look that way.

Eastern water dragon enjoying the attentions of the papperazzi.

Paper daisies.

Thysanotus tuberosus. Another one that’s all over the place.

A teenaged darter hanging out in the local equivalent of a bus stop.

Not just charismatic megafauna. A Botany Bay Weevil.

Lace monitor. Okay, we see these at home too.

Eurasian coots in the mist. Not a good movie title.

A fabulous place. It’s tempting, what with proximity to World Heritage listed Wollemi National Park and all, to think of it as a wilderness. But no. Its gorgeous waterways are the product of a 1920s dam built to to supply a cement works, its teeming fish the introduced gambusia affinis – the “plague minnow” – that outcompetes the locals, though it does seems to keep the mosquito population down. As a camper it’s hard to argue with that, although we didn’t see a single bat, micro, macro or meso, during our five day stay.

There’s something to be said for human intervention, as Tim Low says. In the absence of railway station eves or even a well put together shed, the welcome swallows in desperation had to resort to nesting on the natural stone outcrops. But the local water dragons and turtles seemed to relish the fetid smelling pond downstream from the dam.

A water dragon – is it a grotty eastern or is it something exotic?

Gambezi fish – mosquito killers or just killers?

Welcome swallows making do with a natural rock outcrop rather than the eves of a railway station or public toilet

A tranquil place with a violent past. A “natural” place shaped for a very long time by people in ways that you see and ways that you (or at least I) don’t know enough to notice. A familiar story, on sandstone and otherwise.

Posted by

mccnmatt

Posted on

December 31, 2014

Posted under

Backyard chickens, compost, Gardening, Geology, History, natural history, Soil

Comments

2 Comments

Happy International Year of Soils!

1967 photo of the cuttings for the freeway at Brooklyn on the Hawkesbury. http://www.ozroads.com.au/NSW/Freeways/F3/ConstructionInfo.htm

I’m not kidding. The UN has declared 2015 the International Year of Soils. And not before time. Everyone should be preoccupied with dirt. I know I am. What is going in down there, under the ground? Are my veggies growing in podzol or mycelium? Hang on, that’s soil profiles in Minecraft, not in Berowra.

The CSIRO’s recently released Soil and Landscape Grid with its 3 dimensional digital soil attribute maps could resolve most Australian gardeners’ soil questions. In case you were wondering how these maps were developed, let me put you out of your misery:

“The spatial modeling was performed using decision trees with piecewise linear models and kriging of residuals. Fifty environmental covariates that represent climate, biota, terrain, and soil and parent material were used in the modeling. Uncertainty was derived using a bootstrap (Monte Carlo-type) approach to derive for each pixel a probability density function (pdf), from which we derived 90% confidence limits”

More kriging of residuals, I say!

Gags aside, this free online resource shows why Australia needs publicly funded science and why sacking researchers in the CSIRO to bankroll Gina Rinehart’s tax breaks is a major error (if you need more persuading, CSIRO scientists also invented WiFi, Aerogard, the permanent pleat, and the word petrichor, which describes the lovely smell of damp earth after rain).

After reading about the rocks in our neck of the woods, however, I’m not sure we are best placed to fully exploit the sophisticated visualising technologies of the Soil and Landscape Grid. The geology around here is pretty danged boring. Other than the odd lens of shale, mostly on the ridge-tops (that is, under roads and houses) it’s Hawkesbury sandstone all the way down, 40 million years and 270 metres of it. Or at least, all the way down to Berowra Creek where there’s an outcrop of more fertile Narrabeen Group of shales, sandstone and clays here and there.

Cutting through sandstone at Mooney Mooney

The humungous cuttings between Berowra and the freeway, showing millions of years of sandstone deposition

More ridiculously huge cuttings on the freeway

Of course, we’re not alone in our preposterously deep beds of sandstone. They’re on display in the Blue Mountains too, though with a few more layers clay and basalt intrusions to break up the tedium.

Huge sandstone cliffs at Wentworth Falls

Layers of clay amidst the sandstone near Wentworth Falls in the Blue Mountains

The humungous quantities of sandstone across a swathe of the Sydney Basin makes my sentimentality about the disappearing rock faces along the new railway cuttings of the Northern Line even more absurd. After reading about the good exposures of Ashfield Shale between Hornsbury and Beecroft, I’ve become a tiny bit obsessed with capturing the freshly exposed slices of Sydney Basin geology as they are revealed by the diggers and before they’re covered with nasty grey concrete. Wordsworth was mortified by the ugliness of railway cuttings slashing their way through the nineteenth century British countryside. Here am I mourning for disappearing railway cuttings, a slice of geological time revealed and then lost again.

Sandstone profile

A slice of sandstone

The sadness of disappearing sandstone

Busy workers covering it all up

Perhaps I should stop grieving the lost glories of the Pennant Hills trackwork and spend more time worrying about what my garden might be doing to the “quartz rich, nutrient poor” soils of Berowra.

My snake beans are kinda sallow – I reckon they need a side serve of well-rotted chicken manure. But even as I contemplate emptying the compost tumbler, I can’t help but fret about where my vegetable garden sits, perched above the national park with its “rich and distinctive assemblage of species that thrive on poor soils” , “60-80 different plant species growing together on an area half the size of an average house block” (Benson, Howell, McDougall, 1996, 24-5). Benson and Howell in their fascinating Taken for Granted: the bushland of Sydney and its suburbs (Kangaroo Press/Royal Botanic Gardens, 1990) mourn:

“much of Hornsby’s rugged sandstone terrain remained undisturbed until after World War III when the increasing availability of the car and improved building technology made steeper, more remote sites available for housing. As a result, bushland on ridge-tops and upper slopes has been totally destroyed, the bush remaining only where it is virtually impossible to built, and along steep gullies which have become drainage lines. Virtually very catchment system includes some suburban development, stormwater run-off from which contains silt and nutrients. These promote weed invasion of sandstone gullies… in newer areas such at Mt Colah and Berowra [the] invasion is beginning, and the consequences appear inevitable” (108)

And that’s us, in our mid-century twentieth century house, teetering on a steep slope in a fold of the hillside you might otherwise call a creek bed. My painstakingly-made hot compost, my organic sugarcane mulch, the poo from my beloved chickens, all building nitrogen, carbon, phosphorus rich earth – garden alchemy. I’m creating an anthroposol – a human made soil – and I’m not entirely sure that’s a good thing.

Yellow podzol? or anthroposol?

Run-off from the garden… sorry, creekbed.

As a homage to the UN’s declaration, I’ve stared in a incomprehending way at a schematic cross-section of Hawkesbury soils, I’ve thought long and hard about our B horizon (by staring even longer at this quite marvellous online introduction to soil classification – thanks again, CSIRO) and I’ve double-checked Minecraft’s definition of “podzolic” with the kids but I’m not sure how far it’s got me.

Maybe this is the chthonic thinking – thinking about the soil and the communities, plant and animal that grow from it – that my friend Kate urges us all to do in her fab blog about the Armidale Community Garden, but it’s not so much grounded me as taken me directly to Hades via the Field of Punishment. This is a special special place of suffering for people who long to understand rocks and dirt but can never remember whether the Devonian comes before or after the Carboniferous, no matter how many times they read David Johnson’s splendid Geology of Australia. And that’s without wrestling with the geopolitics of topsoil loss or the impact of international agribusiness on pesticide residues or the links between soil, country and indigenous chlthonic law…

The only solution to this torment, I feel, is another variant of subterranean thinking: that sense of mindfulness I get sitting in a darkened vehicle with a swag of empty shopping bags, gazing tranquilly at the carefully preserved, sandstone rock exposures in the underground car park of Berowra Coles.

Happy International Year of Soils everyone!