Thursday, October 22, 2009

A swale of a time

It's been a long time, but there's been a lot going on, not least of which has been a swale, dam and tree plantings happening on the peninsula property. First came the the digging and the shaping of the dam and swale. This required big machines - very big machines. So big in fact that there was danger that they wouldn't fit down the driveway.

Then came the digging, and the digging, and . . . . well, you get the idea. Our dam is not so big - not even a megalitre, but while it was being excavated, it seemed we had embarked on a mission to dig to the centre of the earth. As the excavator dumped more and more earth around the sides, we watched nervously.
We spent a lot of time admiring the skill of the earthmover, Rick Coffey, who used the blades of his machines like chisels, making precise fine cuts and moving the machines up impossible angles. As the earth he was working with became wetter, he shifted to the wider-tracked machine. The final track-rolling of the dam wall was heart-in mouth stuff: Rick would move up the steep sides becoming almost vertical, and then when he reached the lip, the machine would tip slowly onto the flat. At various points, my partner and I followed him around with the laser level, helping him to check his cuts, but he was so precise that corrections were rare.

And then finally, after two long days, the earthmoving stopped, and we were looking at our new dam and swale. In the image below you can see the way that Rick has placed topsoil around the lip of the dam and stabilised it by smearing it with the back of the bucket. Very schmick.
The swale runs across the paddock in roughly a south east to north west direction, interrupted by the dam. On the downhill side of the swale is a soft (uncompacted) mound. A wing drain is also part of the system, to take swale overflow. It is really a watering system for the fruit and nut trees planted on the swale mound.

Permablitzing the swale
A bunch of hardworking permablitzers helped us plant out the swale. Susie, Liz, Alastair, Jacquie and family, Gillian, Jo, Jessie, Adam and Christine worked like troopers and planted out a total of 80 trees on the swale mound. 20 fruit trees went in - avocadoes, hazelnuts, almonds and pecans. Around each tree, three nurse trees were planted: 2 tagasastes (Cytisus palmensis) and 1 Acacia melanoxyln. A length of polypipe was buried about 30cm into the earth beside each tree for efficient water delivery to the root zone.

The blitz team also mulched the swale with pea straw and sowed 25kg of field peas over the swale mound. We used a compost tumbler to mix the innoculant and field peas, and it worked a treat. Sowing by hand was, I reckon, the best job of the day. It is very satisfying to fling a seed-filled fist out over fresh dirt with gay abandon.

Eastern wing of swale, three weeks after the permablitz. The field peas have germinated well in the mulch.
The troops ate like royalty, with homemade delish food, as well as platters of baked goodies from A1 bakery on Sydney Rd, kindly provided by Susie and Alastair.
The trees were watered in with compost tea, brewed using the new 200 L brewer rigged up the week before. Christine made the arduous trip up and down the hill with the watering cans, as we didn't have a way to get the tea to the swale in larger quantities. We all had the opportunity to smell the brew, and like the good compost with which it was made, it smelt damn fine: sweet and earthy.
Compost tea brewing.

My partner rigged up the brewer, which is made from: a 200L plastic drum, a powerful aquarium air blower (400 L per minute), black irrigation polypipe with holes drilled in it. a connecting hose to connect the blower to the polypipe, and an aquarium heater. A mesh bag containing compost (homemade for quality control!) and a few other ingredients (we used molasses, worm castings, and seaweed concentrate) is suspended in the drum, which is filled with water. Aeration is then delivered using the blower connected to the polypipe. The whole solution is heated with the aquarium heater, which attaches with suction cap to the sides of the drum. The aerator is run for 24 hours. The tea must be used soon after the brew has finished.

The brewer
The aerator
The aftermath
A month later, and things are looking good. The dam is almost full. The field peas are going strong, and there is good growth on the fruit trees, with the exception of the avocadoes, which are suffering from the wind. We even have our first nut - an almond.
Good growth on a hazel
An almond, already!
I have had to replace a few of the tagasastes which didn't survive their first few weeks as tender young seedlings, and the success of the field peas has meant that I have spent an hour or so each weekend weeding around the nurse trees. We've been unable to plant out the dam wall (the aim is to plant it out with native shrubs, grasses and groundcovers) because its been so wet that Rick can't move the earth around. That will have to wait until December.

In the base of the swale, you can see yabbie holes, and lots of bird tracks - probably ibises going after all the cockchafers uncovered with the earthworks.

Yabbie hole and bird tracks in base of swale
Thankfully the rain has meant I haven't had to water the trees yet, but we are looking down the barrel of a long hot summer so that isn't far away.

Signing off for now
Marie Antoinette

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