Archive for May, 2016

Duck ponds

Sunday, May 15th, 2016

With the building of a duck house, there had to be a duck pond to go with it. or, as it happened, two duck ponds.

In addition to being ponds for ducks, these ponds also form part of the general water-retention strategy for the quinta. The aim is to slow the passage of water through this steep land and spread it as far as possible from the stream, allowing it to infiltrate and hydrate the soils. This promotes the growth of the vegetation which is so essential in improving the soils here. Vegetation decomposes to provide soil carbon. Without soil carbon, these thin soils haven’t a hope of holding onto moisture (or much of their biota) through the hot dry summer months. Irrigation becomes necessary. But build up soil carbon levels enough and eventually irrigation needs are minimal, even zero. So in order to make irrigation unnecessary, it’s initially necessary (at least if any kind of speed is required).

Back to the duck ponds. Or maybe duck puddles would be more accurate. They’re barely large enough to be worthy of the word pond, though they’re more than adequate to keep a couple of ducks happy.

Inlet for the second duck pond

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Ponds four years on

Thursday, May 12th, 2016

It’s been quite a saga, this business of creating unlined ponds. I particularly wanted unlined ponds, because their principal purpose is to provide hydration for their surroundings in the course of slowing the passage of water through the quinta. But as I’ve learned, it takes a while for them to stabilise. There are six of them; two sets of two on the top and bottom terraces above and below the yurt terrace, and another pair of very small duck ponds on the bottom terrace. Small ponds – which these all are due to limitations of terrace width and slope – are much more sensitive to small perturbations.

Spillway between the ponds on the bottom terrace

Spillway between the ponds on the bottom terrace

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Subterranean heating & cooling system

Wednesday, May 11th, 2016

The previous post on the geodesic dome greenhouse outlined the logic in choosing a dome for this site and how it was by far the better option for fitting in all the things I wanted to have in this greenhouse. These include an aquaponics system and a bathroom as well as growing space for tropical and frost-tender fruits and vegetables, seed growing areas, a rocket-stove water heater and a worm farm – a fair bit to cram into an area measuring just 7x5m at the outset.

Geodesic dome greenhouse frame

I also wanted to build in a subterranean heating & cooling system (SHCS) to make even better use of all the thermal mass present in the solid bedrock floor and back wall. This is a proven low-tech solution for maintaining comfortable temperatures and humidity levels in the greenhouse year round. It can minimise or even eliminate the need for supplementary heating or cooling.

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Geodesic dome greenhouse

Sunday, May 8th, 2016

Back in July 2012 we dug a chunk out of the mountainside in preparation for a ferrocement rainwater harvesting tank. Plans for the tank were later shelved due to budget constraints, but a good use for the site was never in doubt. It’s one of the few parts of the quinta to have sun at winter solstice, so was perfect for a greenhouse.

Geodesic dome greenhouse site

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