Wednesday, November 30, 2011

Harvesting Domestic Worm Farms Made Easier

article contributed by Ken Reid

One of the activities in working with worms in the domestic set-up which tends to put off all (except real enthusiast) is harvesting the worm castings (poop.) This is because of the time it takes and the fact that the “worm farmer” has to get his/her hands into the vermicompost—and the really passionate wormer doesn’t want to lose any of his worms in the process! The result often is that the wormer gives up on his worm farm and it falls into disuse. This is a great pity because these domestic worm farms do have a very important role to play as every family who has one working is contributing in a positive way to slow down the impacts of climate change and soil degradation.

We should also look at the reasons for harvesting. The most obvious and commonly used reason for the domestic wormer is to remove the worms from the vermicompost, so that it can be used for conditioning or improving soil. But there is another one and that is when it is necessary for the worm population in a wormery to be reduced, in which case the target for harvesting becomes the worms. Usually in the latter case the worms are taken from one wormery to be placed in another, given to friends or used for a weekend’s fishing! (I personally prefer fly fishing to fishing with my friends!)

To illustrate just how important these small contributions are, I often fall back on the following example. Research has shown that the average family of 3 generates between 500 and 1 000g of worm-friendly kitchen waste every day. Taking it at the lesser of the two, this means 3.5kg per week or 14kg per month. Now it does not take a mathematical genius to work out how much this amounts to every year, or how much a community of 20 000 such families or 1 million (similar to some of our bigger South African cities) would be generating. Then consider how much of this would be going on to landfills were it not for people who see the advantages of using worm farms which convert this waste into very beneficial vermicompost.

Being aware of this tendency to avoid harvesting, I have been actively looking for ways to make it cleaner, easier and more fun. The best methods that I have been able to come up with so far are confined to rectangular or square wormery units only, i.e. the ones that one comes across most often at hardware stores and garden centres. The biggest problem with the round, multi-level bin systems lies in the fact that each tray must lie firmly on top of the tray below it. So if you have a round bin, I am open to your suggestions as to how to make your task easier.

The solution I have found for the rectangular bins (whether they are single or multi-layered) came in part from Charl Pienaar’s excellent little book Goodbugs, Little Workers and in part from my constant search for making the job easier and less time-consuming for myself.

What you need
I have found these items really make my life a lot easier when harvesting:
  1. To buy a rectangular plastic fruit tray (obtainable from most plastics warehouses or catering suppliers) which will fit easily into the worm bin; or
  2. To use a rectangular (or square) seedling tray (I have found the big ones work great in my 70lt bins, in spite of the fact that these only have holes at the bottom. Whichever of these two containers you use, the steps are the same. )
  3. A pair of kitchen gloves as I truly believe that it is easier to handle the worms with gloves than with bare hands—and also a lot cleaner should you be called to the phone or anywhere else while you are in the middle of harvesting;
  4. A few large flat plastic basins, one to contain water for rinsing and another for carrying the basket to be harvested from the bin to the work surface, which should be in good light, but not full sunlight. This helps to reduce loss of worms “in transit.”

Start the process at least one week before you actually harvest. This is to give the worms time to “migrate” into the basket.

How to do it
You fill the tray/basket with kitchen peelings (preferably those which have been “ripening” for a few days). Open out a space in the vermicompost in one end of the bin which will allow this basket to fit in neatly) and fit the basket/tray into this space.

Once you have done this, cover the tray with a thick layer of damp paper or cardboard, but leave the rest of the castings exposed to the light. Instead of replacing the bin lid, cover the bin with either clear glass, clear Perspex sheeting or heavy-duty clear plastic sheeting, which must be well secured so that no unwanted predators get in.

After a few days you can remove the basket, which will be full of worms which have migrated into the new food source and away from the light. Put the basket gently into a large basin for carrying to the work area.

Tip the contents out onto a flat working surface and catch worms in large numbers!

You will find that it is very easy to collect the worms in this way and place them where you want them to go, which might be into another bin.

Repeat this process a few times until you find that your basket no longer attracts large numbers of worms. By this time, the vermicompost that you want for your garden can be removed from the bin and prepared for use in the garden. All the unprocessed material goes back into the system for the worms to carry on their good work.

I have found this method speeds up the harvesting process considerably, as I can now harvest 1kg of worms in about the same time that it used to take to harvest about 250g. This means that I am able to do the job about 4 times faster than with the old “dump and sort” method.

Climate Justice

Interesting article here by Alex Lenferna on climate justice.

Something that occurred to me is that developed economies have a lot of infrastructure that will have to be replaced. Why not, instead of making that the top priority, invest in clean energies in poorer countries? Developed countries as their first priority should focus on energy efficiency, planning away urban sprawl and taking away cost advantages of dirty energy for new projects. Those changes should in principle buy emissions cuts of around 20% with relatively low cost.

In the meantime, developing clean energy sources that today have not been tested at scale can happen in countries that do not currently have much energy infrastructure. This way, as developed economies retire dirty technologies, there will be an increasing amount of practical experience with renewables.

In Africa, especially outside South Africa, much of the continent has no power grid. Implementing small-scale local energy sources in that context is already reasonably cost-effective; work on making that better, particularly energy storage and you have a solution the rest of the world can use. My example of how Africa can jump ahead is with cell phones, which also have the advantage that their infrastructure can be rolled out incrementally as demand rises. Compare the rapid rise of cell phone use in countries like Nigeria, with the sluggish growth in access to landlines across the continent.

Tuesday, November 29, 2011

COP17 Day 1

At the end of day 1, the biggest news item out of COP17 that I noted was the US refusing to accept binding emissions targets without the rest of the world signing up.

For more, see Alex Lenferna's report, COP 17′s Youthful Hope in a Climate of Stale Politics.

The problem is, the US and other historically high emitters are responsible for a large fraction of the extra CO2 that's in the atmosphere now, and will be there for centuries. About 50% of emissions are absorbed quickly by the environment, mainly the oceans, but also an increase in absorption by the land, and enhanced plant growth. The rest is drawn down by much slower processes, and climate change caused by an increase in CO2 could be with us for as much as 1,000 years. That means the US is already responsible for a large fraction of the problem. What's more, the US can act unilaterally by both taking strong moves domestically to cut emissions, and by imposing a carbon tax on imports.
Fraction of initial increase in greenhouse gases over time

This picture (from the supplement to a paper published in 2009 on irreversible climate change) illustrates how a large fraction of CO2 added to the atmosphere will still be there in 800 years, even given the uncertainty in the rate at which the environment can absorb emissions (given by the grey area in the graph). This uncertainty reflects our inability to predict the climate that far out into the future with great precision. Nonetheless the fact that we are carrying out an experiment with consequences that will be felt for 1,000 years suggests we should be taking efforts to turn things around seriously.

Back to the effects that a unilateral US action could have; better still if Europe was dragged in.

The US and Europe have off-shored a lot of their pollution, especially to China. The US remains the world's biggest consumer nation, with nearly a third of worldwide consumption, and many of its imports are from countries that would have to adjust their policies if the US imposed a high carbon tax on imports. The US, therefore, is in a strong position to change the world emissions economy by acting unilaterally. As an example of how this kind of leverage works, I was told by someone in the US that Canada in the 1980s introduced a law requiring that new cars have an extended warranty against rust. Canada is a relatively small market and manufacturers could not justify building cars on a separate production line just for Canada, so all cars destined for North American buyers benefited. I can't find any definitive reference for this story, but that kind of leverage can work.

In short, the US was a major cause of the problem we now face and can't fall back on the logic of we can't move until anyone else moves. And as a major consumer nation, they can provide a strong incentive for others to clean up their act.

Sunday, November 27, 2011

Buy Local

Buying local is a key adaptation to a world of more expensive energy, and it is something we can start to do now, not wait for COP17 to fail.

I am on the whole I sceptical of “individual effort” as the key call from politicians for addressing climate change: it becomes an excuse not to address the major systemic changes we need, like replanning cities to reduce urban sprawl, making public transport a viable option for those who own cars, and replacing coal-based power generation by clean energy. Nonetheless individual effort has a role: those who care enough can set an example, and when enough people care, political action follows. I lived in Australia for 9 years, and when enough ordinary people were fed up with politics as usual, the political side of the Green movement grew to the extent that today, the Greens hold the balance of power in the federal parliament as well as in the Tasmanian state government. As a result, we are seeing real action there, like feed-in tariffs for clean energy and a carbon tax.

In any case, the reality is that as energy becomes more expensive, buying local makes increasing sense, and this will happen as fossil fuels deplete, no matter what governments do about climate change. Add to that the community-building effect of more local employment, and meeting people when you go out to a local market, and buying local has a lot to recommend it. This sort of change is something we can all work for, and have fun doing so. In a small town, we can set an example on a small scale for others to follow. And building consciousness of the environmental cause is not all about protests, petitions and politics. We need to have fun, and demonstrate that the alternative lifestyle we promote is something everyone can live with.

Bread as it should be
The bread line
Grahamstown has several markets, including a regular one on Saturday mornings, starting at 9am outside the old gaol on Somerset Street. This market is a small informal affair as befits a small town, but you can buy some really good stuff there, including farm-fresh vegetables, a variety of local cheeses plus some from elsewhere in the country, artisanal bread and fresh fish.

queuing for fish
The modern concept of a shopping mall is highly car-centric. Everyone who needs to shop piles into a car, or some sort of luxury urban tractor, to go shopping in a place where it’s safe to walk around, because there are no cars inside. Then the shoppers all sit in traffic for half an hour, and head back to suburbia, where it’s marginally safer for the kids to play than the city centre, because there are fewer cars. Contrast this with the older style of city, with good pedestrian spaces, street-level shops and people living and working close to markets. The older style of city tends to be healthier, because people exercise more just going about their daily business. It also promotes a greater diversity of trade, because a small shop with a street front selling a narrow range of specialities can trade to people walking or cycling, who don’t have the hassle of finding parking before they can go into the shop.
Not the Monty Python cheese shop

Adapting to climate change and peak oil isn’t all bad, if it forces the end of car-centric shopping. We could all be fitter, healthier, enjoy shopping more, and live in a happier community with less unemployment.

Jam with a smile
How can we advance that cause in Grahamstown?

For a start, patronise the existing market, and small shops, rather than do all your shopping at a chain supermarket. Walk or cycle to the shops: unless you are picking up something heavy, this is easy for most residents (though suburban sprawl has hit the outlying areas). Also it would be a useful project to promote urban gardening, especially among the poorer people of our town. If they had access to a market, it would add to their income, adding to the general happiness and well-being of our town.

Friday, November 25, 2011


This blog is about advancing the green agenda in Grahamstown and the Makana council area. It is a public forum, and comments policy is generally open. Comments to older articles will be moderated to discourage spam, but no comments will be deleted unless they are either clearly illegal or spam.

Some of the issues we will look at include global problems and local responses. Some examples:
  • equity – we talk about the environment as if it’s something out there but a lot of environmental concerns deeply impact the poorer parts of society
  • climate change – the science, policy options, and what we can do here
  • peak oil – the inevitable rise in costs associated with the oil economy, and what we can do to mitigate these costs locally
  • policy agenda – how we can influence local and global policy on matters of sustainability
If you want to contribute, use the contact form (click Contact us here, or at the top of the page). I welcome contributions. If you want to contribute regularly, let me know.