Data-driven allotment: GRI 13.8 - Waste

Introduction

This is one of a series of posts about one of my favourite topics - my allotment! And more importantly, how green it really is, using a selection of topics from GRI Standard 13: Agriculture, Aquaculture and Fishing Sectors.

I am a big believer in learning by doing, so when the Global Reporting Initiative released its standard for the agriculture, aquaculture and fishing sectors in 2022, I thought the best way of getting to grips with it was to try to apply it to my allotment. As I’m sure you can imagine if you’ve ever reported under the GRI standards, this was a challenging task. Firstly, quite a few of the topics simply aren’t applicable (or ‘not material’ as the Standard itself puts it), For example, I don’t keep livestock on the allotment so I don’t have anything to say about 13.11 - Animal health and welfare. Others I can address, but only indirectly, so whilst I don’t use pesticides, I can think about 13.6 - Pesticides use through the lens of ‘organic’ alternatives to conventional pesticides. You can find a complete list of the standard’s topics and which ones I have decided are immaterial or of limited applicability here.

Perhaps unsurprisingly, given my interest in horticulture and food systems, I am also interested in the ‘business’ side of the allotment - i.e. doing a very basic cost/benefit analysis. As I worked through the topics, it also became clear that this information was relevant to topics like 13.3 - Food security and 13.21 - Living income and living wage. Ultimately, I’ve ended up recording both environmental and financial data, some gathered myself and some from reliable sources like the Met Office and the Soil Association. The different types and sources of data are summarised here.

Whilst I have made every effort to be as thorough as I can be about this process, it’s important to remember that this is just an intellectual exercise for me, and I make no claim to the sort of scientific rigour that large food-producing businesses have to put into their reporting.

On to the interesting bit…

This month’s focus is GRI 13.8 Waste.

I have to confess, I was originally going to write about soil health this month. My plan was to have the nutrient content of my soil analysed now, just before we move into the growing season, and then again at the end of the year to see if there was any noticeable change in the nutrient levels etc. I was also planning to do a comparison of the nutrient contents in a bed that had been covered with a green manure of field beans all winter vs. one that had been cultivated with kale. Unfortunately I wasn’t able to get my act together in time, and I only just collected the samples, so that analysis will have to wait for a moment.

Instead I’ve brought forward a topic that I have been putting off. Not because I have nothing to say about it, quite the opposite in fact – I find the whole issue of waste really complicated, especially since I’m not sure how helpful it really is as a concept at a time when we are trying to move towards a more circular system. In a circular materials flow, of course, there is no such thing as waste, because every non-usable output from one value cycle theoretically should have value in another. So I’m going to try and expand the question of ‘What waste does my allotment generate?” to a more general “How can I use my allotment to close the material flows over which I have an influence?” There will, unavoidably, be some overlap with the ‘Producing instead of buying-in consumables’ section of this previous post.

According to GRI 13, waste is “anything that a holder discards, intends to discard, or is required to discard.” And that’s fair enough - an allotment generates all sorts of outputs, some of which is clearly beneficial (i.e. primarily edible food), and some of which less so (e.g. plastic waste from netting packaging). It seems like the assumption underpinning the GRI’s definition is that it’s the process of discarding an output that turns it into waste, rather than an inherent property of the output itself. It’s a perfectly reasonable approach in most systems, but in a system that deals primarily with biological outputs, I’m not sure it’s the most helpful. But before we get into that…

…let’s start with the obvious stuff

I do, of course, use some items on my allotment that I can’t compost or easily recycle. Whilst I try not to bring in anything new of this nature, it is sometimes unavoidable. For example, I recently got some plastic netting made in a custom size so that I could staple it to posts to support my peas, beans etc. This was part of a time-saving campaign intended to reduce how long I spend setting this kind of structure up every year. And they will be reused from year-to-year. ‘Reuse’ is, of course, on of the original 3 R’s (reduce-reuse-recycle), but as pointed out in Welcome to the Circular Economy, it is far from the only option. So here are my choices for how to deal with plastic and non-biodegradable waste as I see them:

Reuse

The netting is not the only thing I try to reuse on the allotment. I also try to keep my plastic seed- and cell-trays in as good a condition as possible so that they can be reused. This is something of a uphill battle though - they simply aren’t designed to last very long. And once they start deteriorating, they become essentially unusable. The other disadvantage of plastic seed trays (which I didn’t know when I bought them) is that they are very difficult to recycle. I’ve heard conflicting information on why this is the case, but it seems to be a combination of the actual polymer composition, the lack of labelling, how difficult they are to clean once they’ve been covered in soil for years, and the fact that black plastic is surprisingly difficult for machines to sort. The same is true of the round pots as well, but I’ve found they tend to be rather studier, and I do have a supply of them that I intend to keep using pretty much indefinitely.

So I was very excited when I saw at a local garden centre that you can now buy rubber-based plug trays. Not only is rubber – theoretically at least – fully recyclable (or indeed eventually biodegradable), but it’s also much more durable than those plastic trays, so that sounds like a double win! (I have also seen silicone trays for sale, but I haven’t tried those.) There are a couple of downsides though: for one thing, they’re more expensive, but this is counterbalanced by the fact that they’re more long-lasting, so a better investment than cheaper but less durable plastic trays. Another major downside is that, at least at the moment, they only seem to come in non-standard sizes, i.e. not in the sizes that slot neatly within the trays and shelves I’ve got set up on the plot at the moment. This doesn’t sound like it should be a major problem, but at this time of year, when it seems like every square inch of the polytunnel is crammed with seedlings, losing a 2-inch gap all the way round a tray does feel inefficient. Of course, if these products catch on, the major manufacturers will probably start producing their own standard-sized products in this material. And of course, we have to pay careful attention to make sure that the rubber itself is sourced sustainably and ethically – for example, the brand I buy is certified as not being produced on land that was deforested. So that’s option 1: invest in longer-lasting reusable products.

Replace (with biodegradable products)

To an extent, I already do this. I get everyone in my family to collect their old loo rolls and kitchen rolls – with a few quick snips and folds, they can be turned into quite serviceable (if only single-use) root trainers. I like doing this for a couple of reasons. It is more sustainable than using plastic, even if it is probably a lower-value way, from a value-cycle perspective, of dealing with cardboard than recycling it. It’s also easier when it comes to planting out, because you can just dig a hole and plonk the entire thing in the ground without having to worry about disturbing the plant’s root system. Of course, they do dry out faster than plastic seed trays, as the cardboard absorbs any water you apply. On the other hand, you can’t let them get too damp, or they just collapse. I tend to use this method for beans, tomatoes and anything that doesn’t like its root system disturbed, like cucumbers. And another, less obvious advantage, is that when the cardboard breaks down, it adds brown material to my soil. This is important as I don’t really get a lot of brown (i.e. carbon) material to counteract the sheer volume of green material that any primarily annual-growing allotment tends to produce.

I have also in the past used those kits for making pots out of compressed paper. They’re fine (provided, again, that you’re careful about how much water you apply to them), but now that the local free newspaper is no longer delivered, I don’t tend to have much material around that can be used for these sorts of pots. I could go round to the train station and pick up a leftover free paper, but that seems more like turning a resource into waste than turning waste into a resource. It’s also a very time-consuming exercise to make enough to get you through a year, and you have to store them unfolded or they just collapse, so they take up space as well, which is often in a limited supply during sowing season.

What about coir pots, I hear you ask? Coir, if you’re not familiar, is a fibre made from coconut husks that can be compressed to make biodegradable pots. And I like the idea in principle, but I see a few problems. For one thing, they’re comparatively expensive for a single-use product. And I can see why – the processes involved to produce them are, I imagine, quite costly. So to buy enough of them for an entire growing season would be quite a financial commitment. Then there’s the environmental considerations. How much carbon does it emit to ship tons of coconut husks around the world? I suppose you could argue that the coconuts would be shipped anyway, so bringing the husks with them is fairly carbon neutral, but as with all of these wonder products, it comes at an environmental cost. Coir pots are convenient compared to some of the other alternatives, but it’s important – as with the rubber trays – to ensure that that convenience does not blind us to the environmental impact. And there also seems anecdotally to be something ironic around these pots in that, for a product whose USP is that they replace plastic in the garden, a surprising number of them actually come wrapped in plastic…

This last criticism also often applies to another produce I use: nettle twine (instead of plastic alternatives). I like this product because it has the double advantage of being more sustainable and also much easier when it comes to clearing beds at the end of the year. You don’t have to fiddle around untangling all the twine that was supporting your tomatoes, you just chuck the entire thing in the compost bin and let the worms and microbes do their thing. Like coir pots, nettle twine is more expensive than the plastic alternatives and not particularly easy to get hold of. A common alternative, jute twine, is readily available and generally of a comparable price to plastic twine. But like coconuts, jute only grows in tropical climates, so it just isn’t possible to produce the raw materials that go into jute twine in the UK on an industrial scale. I’m not sure about the biodiversity impact of jute, but I know that nettle patches provide fantastic habitats for various species, which correlates with what I have observed in the nettle patch that covers quite a lot of my new allotment. They’re also a very low-maintenance plant (in fact, the challenge is often to stop them growing…), and I do use the leaves from the nettles as a quick-decomposing mulch as well. So to over-simplify massively, nettle twine does have the edge over jute twine from a sustainability perspective.

It does often still come wrapped in plastic, however, and that’s why one of my projects this year is to apply my relatively recent spinning skills to making my own nettle twine from the nettle patch that has been growing, despite my best efforts, at the top part of my new plot. More on that to come later…

So replacing non-biodegradable products with biodegradable products is an option, subject to a few caveats.

Refuse

Would it be possible to eliminate the need for some of these products altogether? This would obviously be the ideal – needing fewer materials obviously means less waste. To be honest though, I struggle to come up with ideas for supplies I could eliminate from the allotment because I already try to do things with minimum inputs.

One thing I have been intrigued by recently, however, is using a soil blocker to start my seeds off, rather than trays, whether plastic, rubber or otherwise. I have seen on a couple of different social media feeds that various organisations are trying them out. You might have to google what they look like if you’ve not heard of them before, as I’m afraid I don’t have any pictures. The basic idea is that they create blocks of compressed compost that you can then plant your seeds into. The blocks, ideally, should be compressed enough that they hold their shape until the seedlings are ready to plan out. I have to admit, I’m intrigued - it would definitely be a good way to start off seeds that don’t disturb the soil too much as they emerge, like lettuces and brassicas.

However, I expect that sowing something like beans in them would be challenging, as I can only imagine the roots and the rising shoots would push the soil apart and the whole block would crumble without anything holding the sides in. That said, I have see pictures of squash seedlings growing out of these soil blocks, and I generally think of them as quite disruptive growers, so maybe I’m overthinking it. Another challenge would be keeping them moist enough to hold their shape. I have mentioned previously that I’m trying to use my own compost as much as possible this year, and whilst it is a perfectly adequate growing medium, it’s not the best at retaining moisture (I know, I know, it needs more organic matter, and improving my composting is something I’m working on this year). Despite all the rain, it can be a challenge at this time of year to keep my seedlings watered, since the water supply to the site is turned off during the winter and only normally tuned back on around now. To get round this, I tend to water by filling up the bottom of the underneath tray and letting the water be sucked up into the seed trays by osmosis – would this work with these soil blocks? Or would it just destabilise the whole thing? There’s only one way to find out, I suppose!

And it’s not just the ‘consumables’ that I could look at replacing. I have previously mentioned my plans to replace part of the path currently covered in weed-suppressant fabric with beds for pollinators. But on reflection, I think I could take it further and replace all of the path currently covered with that fabric with either thyme or chamomile lawn paths. Not only would this reduce the amount of microplastics potentially being released in the soil, it should hopefully (once established) be lower maintenance. One weakness I have found of that sheeting is that you have to keep brushing it down to remove any soil that blows onto it. Otherwise grass gets established on top of the fabric, then roots down through it, making it a huge pain to get rid of. Every time I have to do this, I think how much better it would be to just have a chamomile lawn, and I have over time convinced myself that it’s the best option.

There’s a problem though – what do you do with the plastic you’ve removed? I might be able to put some to use covering up beds in the brief periods that they’re bare, but what about the rest? I think this is something that gets lost in debates about replacing plastic. We know that the most sustainable product is the one you already own. But does that mean I should just leave it until there’s no option but to replace it? This is a genuine question incidentally, one that I don’t have the answer to.

So replacing is also an option, but the replacements have to be viable and whatever is being replaced needs to be carefully disposed of.

Recycle

Perhaps the most famous of the R’s, what does recycling look like on an allotment? Well, the standard actually cites the environmental risks associated with disposing of “hazardous waste, such as pesticides containers”. I don’t use pesticides, but I do have a small stock of synthetic fertilisers that I use for my tomatoes etc. I try to keep my use of these to a minimum, and ideally in a closed system, there would be almost no need to add synthetic fertilisers. I’ve never actually got to the end of a bottle, so I don’t know what I’m going to do about recycling them. I believe they can theoretically be recycled, but they would need to be really thoroughly cleaned. Could I reuse them? I am in the process of getting a comfrey patch established for use as a general-purpose fertiliser, and whilst I prefer to just apply the comfrey leaves directly, I suppose I could make comfrey tea and keep it in these bottles, thereby reusing something that is, ultimately, a single-use product.

Whether it’s better to reuse or recycle single-use products is something I do worry about, because I do take some items from my domestic waste and recycle them on the allotment. For example, I use leftover takeaway containers and those plastic fruit punnets you get from supermarkets as mini-cloches and mini-propagators. I’ve found that the translucent takeaway containers with no air holes are particularly useful at this time of year because I can lay them on top of trays to trap in evaporating moisture in the polytunnel to stop my seedlings drying out. There’s five resting along the lengths of the guttering sections that my first peas are germinating in right now. I definitely get value out of them in this way, but does this reduce the value of these materials in the recycling system? It all leaves me a bit baffled: Is it better to make ongoing but value-decrease use of waste products, or to put them back into the system in as pure a form as possible?

Biodegradable waste

One type of waste that definitely does get recycled on my allotment is anything biodegradable. Obviously there’s quite a lot of this – pretty much anything that comes out of the ground that I don’t take home to eat goes into the compost bins (with the odd exception of blighted potatoes etc.). And I do love the magic of composting, though I don’t tend to take kitchen waste back to the allotment. This might sound somewhat wasteful, but I worry about putting actual food waste like peelings into my compost bins because of potentially issues with vermin. We have at least one very bold fox on the allotment, I have had mice in the shed once before – I’m really keen to avoid anything like that happening again. I know it doesn’t make sense - after all, I put things like inedibly damaged fruit it straight in the compost bins without similar concerns. I suppose one option might be to invest in a worm composting system, but I live in a flat, and there’s something about the idea of having that indoors that I’m not comfortable with. I could theoretically have it on the allotment, but there’s not really any properly sheltered spots where the temperature stays consistently in the worms’ comfort range. So for the moment, I’ll be sticking with my conventional composting approach.

One problem I face, however, is that the mix of ‘by-products’ that my primarily-annual growing style produces are mainly ‘green’, i.e. damp, leafy matter and relatively little ‘brown’, i.e. dry twigs, bark etc. To achieve efficient aerobic composting, it is generally advised to mix green and brown matter in roughly equal parts. Get the mix wrong, and you might end up with anaerobic digestion, which is not only slower but also produces methane. Methane, if captured, can theoretically be a useful fuel, but if allowed to escape into the atmosphere it is a greenhouse gas, a more potent one than carbon dioxide. There is, notably, a growing sector concentrating on using anaerobic digesters to break agricultural waste into nutrient-rich digestate and ‘green’ biogas, composed of methane and carbon dioxide.

When you go down the composting advice rabbit hole (as I’m sure you have), you find that there are possible alternatives – specifically shredded cardboard and paper. Both of these are, ultimately, made from carbon in the form of wood, so it makes sense that they would be used to boost the brown content of a compost bin. But this is a bit of a conceptual problem – I said above that I try to view the allotment as a closed system, so is that compatible with bringing in materials from outside the plot? In the strictest sense, I guess the answer would be no, but then maybe this way of thinking is not really that helpful, or even realistic.

After all, surely I can’t just keep taking nutrients (in the form of food) away from the plot and expect it to produce the same level of outputs next year. Surely it can’t be all take-take-take? And of course, it’s not really a closed system – the rain brings nutrients from the larger nutrient cycle, nitrogen floating in the air is fixed in the soil and, crucially, the plants use the magic of photosynthesis to turn carbon dioxide and light into sugar to fuel their growth. So perhaps my quest for a 'closed system’ only works if I expand the system to include the food I eat and all the various resources that inevitably pass through my hands in various forms.

Waste not, want not

So in the end, I don’t suppose my allotment will ever be truly zero-waste. But then – as we all know – what we need is a majority of people doing things imperfectly rather than a minority doing things perfectly. The other takeaway, I think, is that if you want to reduce your waste, you have to think as much about your inputs as about your outputs. This is something that can get lost when companies start thinking about their waste – the answer is not only to think about how you can redirect your waste streams away from landfill and towards more productive sources but also to think about how you can divert other producers’ waste sources into your inputs. The question of how much of my input resources I can ‘produce’ internally is probably subordinate to that larger goal of identifying where I can add value to the other waste streams that pass through my hands.