I live on a sand spit. My guess is that under my feet the sand upon which I live and walk is, as 'soils' go, very young. I need only scrape away the first few centimetres of greyish top soil to expose the pristine yellow granules below.
Water runs through this stuff like a sieve and many of my neighbours have installed spear pumps to access the aquifers as it is quickly underground where all the water goes.
So growing stuff on sand is a hard ask.
Nonetheless, I grow vegetables.
My oldest garden bed is 10 months old and in succession age reduces so that my 'youngest' is 5 months. When you handle the soil on these beds the difference in age is very apparent because I've been layer mulching this garden since I laid it out. The older beds now boast a layer of rich sandy loam.
My primary mulch resource are grass clippings that I get from local mowing contractors. To this I've been adding some horse manure from local farms. When I can get it, I collect sea weed -- primarily sea grasses washed up on the local shoreline -- and spread that out. My commercial one additive has been blood and bone (with potash).
My major gardening activity -- the most labour intense -- is wheel borrow-ing cut grass to the garden and spreading the clippings arm full by arm full.
But Winter has been tough. The cooler months are the driest time of the year here in the sub tropics so it is hard to keep water up to the garden as I rely on one 3,000 litre tank. Because the rainfall is slight, grass doesn't grow so I don't get supplied with grass clippings and keeping up with the break down of the mulch layer over these last few months has been difficult.
Nonetheless over this time, I've been harvesting herbs, salad greens, tomatoes, silver beets, zucchini, eggplant, chokoes, capsicums, sunflowers and spring onions.
When I run out of tank water it is frustrating as I'm keen not to resort to town supply. It is these water issues that have been the most challenging so far. I use a Leeaky hose system to water the beds and carefully ration the volume I irrigate with bed by bed.
These dry conditions force me to experiment with novel ways to hold the water at the root layer.
Adding organic matter to the sandy soil has generated loam from sand, but my loam is still very sandy and shallow so I don't hold as much water as I'd like. So now I'm re-layering the paths between the beds with thick sheets of newspaper and cardboard and mulching over these. The paths are 'irrigation ditches' which function like paper based sponges to hold onto precipitation longer than the surrounding sand.
I've experimented with vertical mulching like this elsewhere by filling trenches with rolled up newspaper, and digging holes next to trees for paper products. I'm finding that once these sheets of paper and cardboard begin to rot, I'm getting a lot of biological activity in these moist cooler environments -- while next door soil may be dry and seemingly lifeless.
My town is junk mail central. As well as two local 'free' newspaper deliveries, we'd get several drop offs each week of bona fide junk mail. Most of this stuff -- aside from what the postie delivers as he also delivers junk -- is thrown at the front fence by passing cars. The inundation is so heavy and frequent that many locals leave the paper on their nature strip... When I go out on my kickbike I collect this flotsam and bring it home. A collecting expedition like this can very quickly generate a harvest of over 3 kilograms of catalogues, brochures and newspapers.
Plants soon get to know where their next drink can be had. My roots may be shallow but they know that there aint much on offer if they dive down deeper for a sip as the water table is two metres down.
Capillary action and local sponge reservoirs irrigate my garden without water being distributed directly to the plants. The engineering makes sense but I'm finding that sandy soils transports less moisture over shorter distances than soils with a greater organic content.
The main game is creating underground environments that make for happy soil life. While I've had some amazing crops of fungi this year (my Mycology knowledge cannot rule on toxicity) I am still waiting for earthworm colonisation to kick in big time. I'm hoping that the replenished sheet mulched paths will encourage soil critters to live local as the paper environments are soon enough musty, moist, cool and populated by a succession of colonising critters. They soon enough become zoo central. So long as I keep monitoring the underground happenings I hope to compensate for the potential for paper mulching to leech nitrogen as it breaks down.
I'm also considering what sort of leguminous crop I can bulk sow to fix the nitrogen in my new soils. Beans have not thrived in my garden for reasons I have not been able to diagnose. So I am thinking that I can break this log jam by planting peanuts -- which also fix nitrogen.
Root crops are for now a waste of effort as there isn't anything below the shallow soil layer to encourage bulbs to enlarge.
My garden is still shallow perched on sterile sand.
The future?
I assumed that the grass clippings would keep on coming and keep me in the botanical comfort to which I had been accustomed. That was a misconception. I need as much grass as I can get and I approach any and every mower contractor I come upon.
Most think I'm mad.
But over Autumn and Winter: zilch!
Once I've re-engineered an extended network of trench mulched paths and replenished the mulch layer all over, I intend to transit most clippings through my chicken coop. Two chooks can do a lot of sorting, turning and pooping-- and once they've worked over and cacked upon my grass I'll put that on the garden beds. So my mulching will be a two stage thing and the chickens may at times find themselves knee deep in cut grass.
I also have access to a feral stand of running bamboo and I'm going to harvest canes and build frames around each garden bed to hold shade cloth during the summer months.
Similarly I need to defend my garden from the prevailing south easterlies. I had planted rosemary bushes for this but they grow so slowly. So I'm pondering my options....A trellis perhaps?
A garden is never finished.
