Received Wisdom - Apply in Small Quantities Only

There's plenty still to do at the lottie. But biting winds some days, frozen soil others, are slowing me down. It does give me the chance to some reading though. I'm not a scientist but enjoy reading explanations by scientists or experts in a particular field about how things work, or, in the case of soil and growing healthy plants, what exactly is happening at the microscopic level and what we do can encourage natural processes to function most effectively.

Of course, you have to choose your sources carefully and, for me, approach every explanation and piece of advice with a healthy dose of scepticism. I'm old enough to have seen scores of 'facts' in the fields of nutrition, health, medicine and plant husbandry proved wrong. Most of us now accept that: blood-letting is not a cure for illness; formula milk is not better than breast milk for babies; homosexuality is not a disease. Too obvious? How about: margarine is not better than butter for your health; having high cholesterol is not a reason for not eating eggs; chocolate does not cause acne. But in farming and gardening, despite some progress in some countries towards the recognition that organic systems are good both for the environment and personal health, many millions of growers world-wide are still being duped by powerful forces to believe that inorganic nutrients added in liquid or granular forms combined with remedial use of herbicides, insecticides and fungicides are a legitimate and sustainable way to grow crops.

But it is precisely because I know how easy it is to persuade when the listener is sympathetic to the argument that when I read about organic growing I don't necessarily want my beliefs to be re-enforced, I want them to be challenged. It is just as possible for 'received wisdom' which is actually nonsense to be handed down as fact in the organic world as it is in the non-organic arena (still chitting potatoes? - maybe wasting your time!). That is why I relish the two papers, both available free online, which I have been absorbed in these last few days. Both, in different ways, have challenging things to say about compost and its value. Both are written by people who are undisputedly supporters of organic systems so I don't doubt their credibility on that score and I am prepared to respect their viewpoint and listen to what they say. I know that both will make me think harder about the complex biology of living soil systems.

Can You Have Too Much Compost?

The first is Steve Solomon's Organic Gardener's Composting. It covers the basics - how to make compost, building heaps, materials - but in great and fascinating detail, and he talks knowledgeably about historical aspects, vermicompost and the vital role of humus in the soil. But for me it gets particularly interesting when he develops a theme with the following prelude: 'Encouraged by a mistaken belief that the more organic matter the healthier, they [home and market gardeners] enrich their soil far beyond any natural capacity. Often this is called "building up the soil." But increasing organic matter in gardens well above a climax ecology level does not further increase the nutritional value of vegetables and in many circumstances will decrease their value markedly.' Talking to puzzled gardeners who came to his talks with tales of disappointing yields, Solomon writes: 'Mr. Organic owned a pickup and loved to haul organic matter and to make and spread compost. His soil was full of worms and had a remarkably high humus level but still did not grow great crops.' and 'In Organic Gardening magazine and Rodale garden books we read eulogies to soils that are so high in humus and so laced with earthworms that one can easily shove their arm into the soft earth elbow deep but must yank it out fast before all the hairs have been chewed off by worms.'

What is the rationale behind Steve Solomon’s belief in the limitations of composting? This links to Chapter 1 of his paper but the challenging material is in Chapter Eight.

Too much of a good thing?

Is It Minerals We Need?

The second heretical paper is Better than Organic - a Conversation with Agricola, by Michael Astera. Astera develops his argument in the context of a supposed interview with one Agricola, not I think the Roman general who conquered Great Britain, but the German scientist Georgius Agricola who is known as the father of mineralogy. This is the clue to Astera's belief that most of the world's farmed land requires re-mineralisation after centuries of depletion. The first question in the interview goes as follows:

Q. You were saying Organic farming and gardening aren’t really working. How are they not working?

Agricola: 'They’re not working on several levels, including corporate greed, business ethics, and of course “We’re from the government and we’re here to help you.” But that’s not what I’d like to talk about today. I’d like to focus on the nutrition aspect, and on soil, plant, and animal health. Specifically, why most Organic food isn’t necessarily more nutritious than chemically grown food.'

Don't let that put you off! It is in essence an argument which points to the futility of adding compost to soils which are minerally deficit but he is a friend of organics and as he develops his theme you begin to be intrigued by his logic (and then maybe go out and buy some rock dust). First is a fascinating review of the writing and research of the early proponents of organic systems. Follow the link at the end of Part 1 to get to the essence of his argument in Part 2

I need to get my soil in such a condition that I can plunge my arm in up to the elbow and risk having my hairs ripped off by earthworms before I can feel able to question the value of compost but while I'm waiting for my humus and worm population to build up I'm quite happy to read this kind of stuff. I might even be able to have my own opinion one day!

Biochar Experiment

An email arrived this week from a company called Oxford Biochar. I had forgotten that some time ago I volunteered to take part in a biochar trial. They tell me they are posting out the kits and instructions very shortly. Few details yet of what is expected of us but I am pleased to get the chance to be involved in a trial of this kind.

Most people who are likely to come across this blog will be aware of biochar and what is claimed of it. Fewer, I imagine, will be using it or have any experience with it. I don't want to run through the whole history, the claims of its proponents or the scepticism of its detractors. (Some of the most informative sources I have come across about biochar are listed here.) But when you have lots of noise and little action, there is nothing better than getting your hands dirty to help provide some evidence.

It seems to me there are two distinct sets of criteria to consider when using biochar. The first is strictly from a gardening viewpoint: is it effective in conditioning soil and enhancing plant growth in organic systems? Under this heading we might include: improved moisture retention, reduced soil acidity, reduced leaching of nutrients, reduced fertiliser requirement, increased availability of nutrients and so on. The second aspect is biochar's potential for carbon sequestration. Under this heading we might include: projected contribution to reduction of global carbon emissions; the economics and environmental aspects of biochar production; stoves, methods of pyrolysis, gasification and recoverable energy, and so on.

If positive conclusions can be arrived for both aspects - then it seems we are on a winner. Can it be a solution to global warming and boost our productivity in organic systems? Many say so but some biochar growing trials are inconclusive or report negative results. And what if governments thought it would be a good idea to give subsidies to farmers to grow crops for turning into charcoal instead of feeding people?. Biofuel seemed a good idea when it was made from the waste from sugar plantations in Brazil but not so clever when the economics made it profitable to use the whole plant and not just the waste.

Important as the second question is, it is the experience of gardeners and farmers that can shed light on the first question. Can we replicate the presumed benefits of the terra preta soils of Brazil? Do improvements in plant productivity only occur on poor-quality soils? To what extent does biochar have to be 'primed' before using? What differences are produced in biochars by varying the temperature of pyrolysis? To what extent does the nature of the source material effect the action and qualities of the end product?

When my package arrives from Oxford Biochar it may just be a small bag of charcoal, a few seeds and an instruction sheet. But even with those modest assets I hope to make a small contribution to a field with many questions and few answers so far. I'll be recording my progress with the experiment on the blog. Please follow!

Screen grab from Oxford Biochar video

Chilly Chillies

It's strange but comforting to think of fiery chillies when icy blasts are rattling the windows. But I am already anticipating my bountiful crop with the arrival of a seed order from Tamar Organics including 30 seeds of my chosen chilli. Last year, pre-allotment and gardenless, the only thing I grew apart from my the solitary potato( Picking Potatoes), was window-sill chillies. Then I chose, without much planning, Early Jalapeno. It's the variety widely grown in Mexico for using with nachos and globally on pizzas.

For me it was a bit disappointing on two counts. It germinated very well, so well in fact I had to give lots of plants away to friends and relatives who helped with the feedback. But the general opinion? - Not very productive, and not enough heat. The mildness must have been something to do with the growing conditions because it is described as moderately hot. So I have promised my brother-in-law, who could eat a whole plant's harvest at one sitting, that I would try and give him something this year that would give him more capsaicin to chew on.

From many possibilities I have chosen a variety called Barak. It is described as producing'extremely hot small bullet shaped fruits produced in very large numbers'. It's a Purira type chilli and this variety matures to red from green purple and other hues making it very decorative. On the Scoville scale it's rated 8, or a tongue numbing 50,000 units. This year I won't have to block off all the incoming light into my flat with chilli plants as I have the greenhouse at the allotment and the extra light and heat may produce better, hotter fruits.

Here's part of last year's crop, well, actually, if I'm honest, nearly all of it, at least from the plants grown by me. (My mother's 8 chillies from her single plant beat my best one!)

Comments and advice on this year's selection appreciated! If it's a good one it will be a) beautiful, b) very productive, c) very hot (really just a variation on productivity as you use less) and d) perhaps will taste nice if not just pure heat. Progress reports guaranteed. Sample chillies posted on request (harvest permitting.)

Are Your Nodules Pink?

After my last post I started worrying about my beans' roots' relationships. In the sub-soil chaos would they find the symbiotic relationship they craved? Would Mr. Bean find the perfect Ms. Rhizobia for nurturing nitrogen together? The simplest way to find out is to have a look. And here is the root system of one of the beans. You can see the nitrogen-fixing nodules quite clearly (click to enlarge) although I'm not sure there are as many as I have seen in other situations.

You'd think that with the evidence of obvious nodules I could relax. But it seems it's not quite as simple as that. The presence of nodules does not in itself mean that significant nitrogen fixation is taking place.' When nodules are young and not yet fixing nitrogen, they are usually white or gray inside. As nodules grow in size, they gradually turn pink or reddish in color, indicating nitrogen fixation has started.' In fact the reddishness is caused by a protein similar to the haemoglobin in our blood and performing a similar function in managing oxygen flow to the bacteria. Apart from immaturity there are two main reasons why the nodules would not be pink inside. One is if the plant has reached the fruiting stage in its development. Its whole purpose in developing the relationship with the symbionts has been to store nitrogen to utilise in the formation of its seeds. That's why green manures are cut down before flowering. Leave too late and the nitrogen is no longer in the ground. The other reason for half-hearted nodule formation and colouring is simply that if the plant can access available nitrogen in the soil it will not invest energy is cooperating with the nitrogen-fixing Rhizobia. (It costs a significant amount of photosynthetic effort to sustain the bacteria.) So in an already nitrogen rich soil, don't expect legumes to add to that store - they will use it instead.

And so it's time for the crucial test of my nodules. It was almost painful slicing them with the craft knife to reveal the internal hue of - green?? 'Legume nodules that are no longer fixing nitrogen usually turn green and may actually be discarded by the plant.' Here's my take on what happened. Until the gales, my beans were growing vigorously and looked very healthy. I'm sure had I looked then my nodules would have been nice and pink. After the storm which flattened them, perhaps they were so shocked that the available nitrogen quickly got used up in trying to repair torn tissue. I'm wondering too at what temperature nitrogen-fixation switches off, if at all. Current soil temperature at depth of 4" (10 cms.) is about 4C.

As usual, I come to no serious conclusion. More questions raised than answered. Will the relationship warm up with the weather? Watch this space. Thanks to W.C. Lindemann and C.R. Glover of Mexico State University for background info:Nitrogen Fixation by Legumes

Vicia fabia + N = mmm, not quite sure

Looking at my wind-ravaged field beans today, planted as green manure, got me thinking about nitrogen. When I last had a garden I lived in the country and had access to as much farmyard manure as I wanted. I, and I think most gardeners then and many now, regarded an annual load of manure as essential to maintaining fertility on the vegetable plot. But I realise now that that fertility came very easily and no-one thought of introducing nutrients, particularly nitrogen, in other ways. Yes, there was the compost heap but in a way it was looked as a way of disposing of material rather than a valuable resource in its own right. Even dedicated organic growers like myself, while totally committed to not using pesticides and artificials, were perhaps better at avoiding certain practices as opposed to actively pursuing strategies to build soil fertility.

Now that I am gardening in an urban allotment, farmyard manure is difficult to source and the logistics and cost of carting to the site make one question its necessity. But if you start looking at alternatives such as green manures, questions arise. For example, just how much nitrogen can be fixed by a leguminous crop? Of course, many variables affect that figure – variety, existing soil characteristics, weather and so on. For a crop such as field beans estimates vary widely from 40 to 300 kg/hectare (37-275 lbs/acre). On these figures my raised bed, which has an area of 7 sq. mtrs would generate a net nitrogen gain of .03 to .21kg (.06-.46 lb).

Of course, as each leguminous crop is associated with a specific symbiotic nitrogen-fixing bacterium, commercial growers inoculate theirs with the appropriate organism to ensure that there is a happy productive partnership (mine had to look for chance compatible partners); and estimates of nitrogen fixation will be based on more substantial growth than mine on this showing. But ignoring these minor points for the moment, how much manure would I have to apply to supply the same amount of nitrogen? Again, wide variations in estimated nitrogen content, specifically available nitrogen content, make this a very rough exercise but assuming available nitrogen at 2% would require about 10kg of farmyard manure on the bed to give nitrogen equal to the high end of the range – at about 3lb/sq. mtr. which seems roughly comparable to what we used to dig in. Non-organic farmers using artificial fertilizer in liquid or granule form spread at the equivalent of about 150lbs of nitrogen per acre.

Although I may have nitrogen levels generated by blind-date symbionts and small plants, on the other hand the farmyard manure is much more susceptible to nitrogen loss through leaching and gaseous ammonia loss; the nitrogen in my nodules is nicely protected and in plant-available form so crude figures have to be balanced by such considerations.

None of this adds up to science; it’s more just a musing. But it is a start in thinking that I will set out to maintain fertility in the allotment without the help of animal manure. I’m not a vegetarian but with manure difficult to get and then possibly tainted by vermicides, the herbicide Aminopyralid, or antibiotics, why not find other ways? To add to green manures, I still have comfrey, compost teas, foliar feeding and urine to add to the mix, so to speak, and of which more later.

Picking Potatoes

I don't mean harvesting them. I've been browsing catalogues and ordered some seed for earlies. Last year, without a plot, I grew one potato in a container. It was a red-eyed variety given to me by a friend. I think perhaps Catriona. (That's the name of the potato. My friend is called Sandy.) I grew it in 100% home-produced, kitchen-scrap compost. General advice is that pure compost is too strong for most crops and as I watched the haulm grow and grow I was imagining that it was a case of 'all hat and no cattle' or, as we would be more likely to say in Scotland, 'all mooth an' nae troosers'. But I was well pleased when eventually tipping out a harvest weighing in at 2.21kg (4.87 lbs).

I don't expect my earlies to crop at that level but we will see what we can achieve as a first crop following the field beans. Local practice is to plant earlies at the end of March but I might try a bit earlier if I cover the bed and warm the soil beforehand. I've chosen Arran Pilot, Scottish bred in 1930 and once grown extensively for the commercial market but now still a favourite with gardeners. My son gave me a great book for Christmas, pandering to my tattie interests: The Potato Book by Alan Romans which comes highly recommended.

If I'm honest one factor in choosing Arran Pilot was because it is listed by Garden Organic, formerly the Henry Doubleday Association. I am a member and therefore get 10% discount!

I still have the pleasure of the book and the catalogues for choosing a maincrop to come.

What Is No-Dig Gardening?

For someone who wants to follow a no-dig gardening system, I have done a lot of digging. Creating the raised beds is an exercise in moving soil with a spade. So I can't really call them undug for a year or two yet. However the point is that now that the beds are constructed from this point onwards they will neither be purposefully dug nor, perhaps more importantly, stood on. To me the logic of raised beds is not to ease bending, weeding and seeding, although that is a bonus, but that they need not be subject to compaction. One argument for digging is to introduce air into the soil but if you have not compressed it in the first place and it is full of compost which has that wonderful capacity to hold both air and moisture in balance, digging becomes an irrelevance.

Of course, when I harvest my tatties I will be digging them out to some extent but I'll do so without inverting the soil. But sometimes soil is dug incidentally. The important point is that I won't indulge in the habit for its own sake. It interests me that many organic farmers who, as opposed to organic gardeners or small-holders, generally, by necessity because of the scale of their operation, use tractors for cultivation (unless Amish), and by doing so are indulging in a practice which is inherently bad for the soil. (One estimate suggests that 30 million hectares of land in Europe have been irreversibly compacted from machine use - see http://ecologyandfarming.com/artikelen/Horses-0411.pdf)

One of the most vocal proponents of no-digging is Charles Dowding. To his credit he has done careful comparisons of dig and no-dig plots which are otherwise identical and he has recorded the crops over a number of seasons. The no-dig plots come out on top, but not by much, and not always with every crop. But, if nothing else, even if there was no difference, why would you bother digging if over time it achieves nothing?

This photo brings the blog up-to-date. It was taken today 3 January, 2012. You can see that most of the work in building the beds is complete. (The green manure in the closest 3 beds is Winter Tares.) There is much work to be done round the edges where I will have fruit bushes and other permanent crops such as rhubarb and comfrey. Then there is the greenhouse - is that an appropriate word for the ramshackle structure to the left? - to sort out. In short the plot looks a bit of a mess but I want to record a start-of-year image for later comparisons.

Composting Dilemma

Everyone says, 'Don't put seeding weeds or perennial roots on the compost heap.', 'One year's seed is another year's seed' and so on. That's all very well. But when you take over an overgrown allotment in July it is all flowering annuals and rampant perennials. It goes against my grain to dump a huge quantity of organic matter so everything was composted and then I made valiant attempts to get the heaps up to the necessary temperature to kill weed seeds but could manage about 40C at the hottest - not hot enough. I now have a nice quantity of compost coming on but is it a time bomb?

I see my allotment neighbours carting off bags of 'waste', presumably to be dumped in landfill, including potato shaws (may perpetuate blight), annual weeds (may have seeds), perennial roots (may survive composting to emerge triffid-like next year). Well they may be right but my instinct is to hang on to all the organic matter you can get. Dealing with the consequences of seed-rich compost may be hard work but at least it should make me look after my plot so that I'm top of the weeding. I'll just settle down to my seven years' penance and get the pleasure of pain in good, old Scottish Calvinist style!


In the foreground is the tip of my weed mountain prior to building a heap.

Getting Down To Work

The first task was to build a series of raised beds. The photo shows progress in October. This is about a quarter of the plot looking up the slope with the golf course behind (municipal not Trump's!) You can see I've used squared mesh and fabric supported by posts. I'm not sure how well this will work but couldn't justify/afford buying a lot of wood. The depth of the beds is created from the soil of fairly deep paths between the beds. I'm actually amazed at the depth and lack of stoneyness of the soil. I should have no excuses if I can't grow long, straight parsnips.

I had already resigned myself to not cropping anything this year but what you can see are 3 beds with Phacelia planted as green manure and at the top, one with field beans. I am planning to use that one for early tatties to take advantage of the nitrogen. Since then we have had a couple of freezing gales and both the Phacelia and the beans have suffered badly but they are serving their purpose in keeping the soil from being exposed to the elements.

Introduction

It is 1st January, 2012 - as good a date as any to start a gardening blog. In July 2011 I took possession of an allotment after three years on the waiting list. This blog is going to record my efforts to create a productive plot based on organic principles, and to follow my experiments with raised beds, no-digging, biochar, rock dust, urine recycling, seaweed teas, comfrey fertilising and sundry other strategies to help productivity, improve the soil and be generally ecologically responsible. I am also interested in growing unusual vegetables and varieties.

I am located in Aberdeen in North-East Scotland, UK. Obviously, where I am determines what I can grow. There are macro-climatic influences but there are also micro-climatic effects from being so exposed and being on a north-facing slope. I'll write more later about the weather patterns but for the moment let us just say that people don't generally grow outdoor tomatoes round these parts, even with the help of global warming!




This is the plot the week I took it over. My daughter is inspecting for potential. In the background is the North Sea and the channel leading right to left into Aberdeen harbour. The land in the far distance is the coastal stretch running north of Aberdeen which includes Balmedie where Donald Trump is controversially building a golf course on ecologically sensitive sand dunes.