Posts Tagged ‘agriculture’
how much damage is synthetic fertiliser doing to soil?
“A nation that destroys its soil destroys itself.” – Franklin D. Roosevelt
In a recent conversation, in which I was accused of being too black-and-white about the positives of conventional agriculture and GMOs, the damaging effects of synthetic fertiliser were mentioned as a negative, as it ‘kills the soil’s organisms, including earthworms’.
So now I’m going to focus on that issue specifically, and follow the evidence where it leads me. There’s no doubt that intensive agriculture and mono-cropping are having a negative impact on soil quality, just as there’s no doubt that intensive agriculture is currently required to feed the world’s human population. So what’s to be done? First, we could reduce or stabilise the world’s population, which we’re trying to do. Second, we can try to find biotech solutions, developing a type of intensive agriculture that’s less damaging to the soil and the environment – and organic approaches might help us in this. GMOs also offer promise, developing crops which require less in the way of fertilisers and pesticides, and deliver higher yields.
There are other ways of looking at this and so many other problems, as I’ve recently become aware of complexity theory, which I’ll write about soon, but for now I’ll look at the claims being made and the solutions being offered.
So what exactly is synthetic or chemical fertiliser doing to our soil? Needless to say, in order to obtain accurate data in answer to this question we have to negotiate our way through sources dedicated to maximising, or minimising, the harm being done. So I’ll start with a definition. Here’s one from a website called Diffen, dedicated apparently to making unbiased comparisons between rival goods and services, in this case chemical v organic fertilisers.
A chemical fertiliser is defined as any inorganic material of wholly or partially synthetic origin that is added to the soil to sustain plant growth. Chemical fertilisers are produced synthetically from inorganic materials. Since they are prepared from inorganic materials artificially, they may have some harmful acids, which stunt the growth of microorganisms found in the soil helpful for plant growth naturally. They’re rich in the three essential nutrients needed for plant growth. Some examples of chemical fertilisers are ammonium sulphate, ammonium phosphate, ammonium nitrate, urea, ammonium chloride and the like.
Diffen goes on to describe the pros and cons, but there isn’t much detail beyond high acidity and ‘changes to soil fertility’. A 2009 article in Scientific American goes further, describing these mostly petroleum-based fertilisers as having these dire effects:
wholesale pollution of most of our streams, rivers, ponds, lakes and even coastal areas, as these synthetic chemicals run-off into the nearby waterways.
What this article doesn’t mention is that human waste (i.e feces), grey water etc is also getting into our waterways and causing damage, and it’s hard to separate out these many forms of pollution. In any case, I’m confining this piece to direct damage to the soil rather than to waterways, important though that obviously is.
One of the principal causes of soil degradation is leaching, the loss of water-soluble plant nutrients through rains and storms, and irrigation. Fertiliser can contribute to this problem. When nitrate (NO3) is added to the soil to boost plant growth, excess NO3 ions aren’t able to be absorbed by the soil and are eventually leached out into groundwater and waterways. The degree of leaching depends on soil type, the nitrate content of the soil, and the degree of absorption of the nitrates by the plants or crops on that soil. Again, though, the leaching is caused by water, and the soil degradation is largely a natural process, though over-irrigation can contribute. This is why the older soils, such as those in Australia, are the most lacking in nutrients. They’ve been subjected to eons of wind and water weathering. The richest areas have been renewed by volcanic activity.
Not all chemical fertiliser is the same, or of the same quality. Phosphate fertilisers commonly contain impurities such as fluorides and the heavy metals cadmium and uranium. Removing these completely is costly, so fertiliser can come in grades of purity (most backyard-gardener fertiliser, the stuff that comes in little pellets, is very pure). Many widely used phosphate fertilisers contain fluoride, and this has prompted research into the effects of a higher concentration of fluoride in soil. The effect on plants has been found to be minimal, as plants take up very little fluoride. Livestock ingesting contaminated soils as they munch on plants could be a bigger problem, as could be fluoride’s effect on soil microorganisms. Fluoride is very immobile in soil, so groundwater is unlikely to be contaminated.
Acidification from the regular use and over-use of acidulated phosphate fertilisers has been a problem in some areas, particularly in Malaysia and Indonesia, where aluminium toxicity has caused severe soil degradation. Acidity of soils is a serious problem in Australia, where in NSW more than half the agricultural land is affected. Most agricultural plants require a pH of 5.5 to 8.0 to grow best, though some plants are much more tolerant than others of lower pH levels. Surface acidity can be corrected with the application of ground limestone, but subsurface acidity is a growing problem and much more difficult to correct. Acidification is generally a slow natural process caused by wind and water weathering, but it can be greatly accelerated by the use of fertilisers containing ammonium or urea. It can also be caused by a build-up of organic matter. As an example of the complexity of all this, superphosphate doesn’t directly affect soil acidity but it promotes the growth of clover and other legumes, a build-up of organic matter which increases soil acidity.
A comment on fertiliser and worms. No, they don’t kill worms, and because they stimulate plant growth they’re likely to increase the population of worms – but there are worms and worms. Some are highly invasive and have been transported from elsewhere. Some can be damaging to plants. At the same time new plants, and new worms, tend to adapt to each other over time. Again, complexity cannot be underestimated.
Another concern about chemical fertiliser, again not connected to soil quality as such, is nitrous oxide emissions. About 75% of nitrous oxide emissions from human activity in the USA came from chemical fertiliser use in agriculture in 2012, and we are steadily adding to the nitrous oxide levels in the atmosphere. Nitrous oxide is a greenhouse gas which, on a unit comparison, is 300 times more damaging than carbon dioxide.
In conclusion, it’s likely that everything you do in agriculture has a downside. There are no free lunches. The key is to obtain as much knowledge as possible, not only about your patch, but about nutrient and resource cycles generally. It’s all connected.
Oh and above all be sceptical of some of the ridiculous claims, and the ridiculous propaganda, out there. Check them out on a reputable, evidence-based site.
more on organic food
Since my post of almost a year ago, on the marketing scam that is ‘organic’ food, I’ve noted that this niche market continues to be less niche and more mainstream, so that I no longer make an effort to avoid it. As long as the food’s fresh, tasty and nutritious, I’m happy.
And yet… I think part of my irritation is that I hate fashion. I mean, why the fuck do all these drongos go around wearing Hurley tank-tops and t-shirts? It’s not as if they’re even remotely interesting or imaginative or anything.
However, I must admit the fashion for ‘organics’ is more comprehensible to me than the fashion for Hurley or Nike, labels for goods that are clearly no better than those of their rivals. It seems that organic food has captured the imagination largely because it sounds environmentally positive for those who want to do the right thing without thinking about it too much. Okay it’s a bit more expensive, but there has to be a price for being on the side of the angels, and it’s nice to be trendy and holier-than-thou at the same time.
Then there are the hardened ideologues who take to ‘organics’ as to a religion, actively seeking converts and feeling smugly superior to those who haven’t yet been ‘saved’. Among those are the real fanatics who warn that conventional food is killing us, that GM ‘horror’ foods and the agribusinesses pedalling them will take over the world and make zombies of us all, and/or that there’s a conspiracy to hide from us the damage that chemically-infested conventional food is doing world-wide.
Of course some will describe me as an ideologue through-and-through, or at least as a hopelessly biased person making fatuous claims to objectivity – a description I’m quite accustomed to hearing – but I can only do my best to be open-minded and undermining of my own prejudices. And if that doesn’t convince anyone I’ll soldier on anyway.
One excuse for returning to the subject is a blog/website called Academics Review, subtitled ‘testing popular claims against peer-reviewed science’, which has posted a piece called ‘Organic Marketing Report‘. Dr Stephen Novella has spoken about the piece on the SGU podcast and on Neurologica blog, but I want to take the opportunity to revisit the issue, as I’ve done so many times in my mind.
For me, three popular claims are made about ‘organic’ food, a kind of ‘nest of claims’ of increasing grandeur and complexity. The most basic claim is that it tastes better, the middle claim is that it’s more nutritious, and the grandest claim is that it’s better for the environment. So let’s look at these claims one at a time, with particular reference to the Academics Review post, where it can help us.
taste
The perception of taste is one of the most subjective and easily manipulable of all our perceptions. Researchers have had a field day with this. You may have heard of the experiments done with white wine dyed with food colouring to look like red, and how this fooled all the wine experts. Numerous other experiments have been done to show that our taste perception can be influenced by mood, by colour, by setting and by the way the food is talked up or talked down before tasting. Then there’s the question of differences between people’s taste buds. What are taste buds? These are the areas on the surface of the tongue, the soft palate and the upper oesophagus that contain taste receptors. Taste buds are constantly being replenished, each one lasting on average 5 days, and it’s estimated that we’ve permanently lost half of our taste receptors by the age of 20. Separate receptors for the basic tastes of bitter, sweet and umami have been found, and the hunt is on for sour. It’s likely that the number of receptors and differences in action of those receptors varies slightly in individuals, so it’s pretty well impossible to get anything substantive out of individual claims that x tastes better than y. However, if in a blind tasting, with a good sample size, we get 80%, or a substantial majority, saying that x tastes better than y, that would be significant.
Of course, it’s difficult to control for all the variables and just to test for ‘organic’ versus conventional. The age of the food, freshness, soil quality, method of growing and various other factors not directly related to organics would have to be neutralised. So we have to take a skeptical approach to all findings.
One blind tasting, reported on here, compared tomatoes, broccoli and potatoes. 194 ‘expert food analysts’ tasted the food and found, according to the report, that the conventional tomatoes tasted sweeter, juicier and more flavoursome than ‘organic’ ones. No significant differences were noted with the broccoli and potatoes. The report doesn’t give the percentage of experts who preferred the conventional tomatoes, and there were some vital differences in the way the produce was grown. In all, not a very convincing study either way.
A series of informal taste tests, conducted in 2007 by Stephanie Zonis, an organic food advocate, comparing eggs, yoghurt, cheese, raspberries and peanut butter among other foodstuffs, found mixed results, mostly a tie in each case, though it seems not to have been a blind tasting and was entirely subjective. She showed commendable honesty, ending with the remark that she didn’t buy organic for the taste.
This cute little video has 3 different products – eggs, carrots and goat’s cheese – and three different subjects tasting them, all of them food experts. Results again are mixed, but the subsequent discussions show that it isn’t the organic v conventional distinction that matters so much. With the cheese it’s the cultures used to produce them, with the carrots it’s the soils and climate, with the eggs it’s whether they’re free range or battery animals, how long the eggs having been hanging around in the supermarket, etc. There are just too many variable to make these kinds of tests particularly useful.
The taste issue regarding organics, I contend, will never be resolved. The trouble is, organic food is constantly touted by advocates (though, to be fair, not all of them) as having superior taste.
Guys, stop doing that.
nutritional content and health
Organics are often recommended as the healthier option, and there are, it seems to me, two aspects to this claim. First, that they contain more and/or better nutrients, and second that they’re healthier because they contain less ‘toxic chemicals’ in the form of pesticides and/or fertilisers. Naturally most consumers of organic foods conflate these two separate issues.
So let’s look briefly at the nutrient issue first.
The Mayo Clinic, the Harvard Medical School and various other reputable sites that I’ve checked out have all said much the same, that there is no statistically significant evidence that organic food is more nutritious. Of course you will be able to find studies, amongst the very many that have been carried out, that do provide such evidence, but that’s to be expected. Overall the jury’s still out. I don’t think it’ll ever be in. Personally, though, I think we can bypass the findings of endless studies by asking the question “How can nutrients be added to food by organic practices?” I can’t quite see how the practices of organic farming – no synthetic fertilisers or pesticides, no food irradiation, no GMOs – can by themselves add to the nutrients of food grown conventionally. If anyone can explain to me how they can, I’d be prepared to take the studies more seriously.
A more complex issue is that of organics and food safety and public health.
This issue is largely a negative one – that organic foods are healthier because of what they don’t have. Unfortunately, this often involves playing up, as much as possible, the risks and dangers of conventional food. The Organic Marketing Report makes some disturbing points here, quoting one organics promoter, Kay Hamilton, speaking at a conference in 1999: If the threats posed by cheaper, conventionally produced products are removed, then the potential to develop organic foods will be limited. In other words, it’s in the interests of organic food marketers to stress the dangers of conventional foods at every opportunity, and this is being done all over the internet, in case you haven’t noticed.
Some 15 years ago, when the organic marketing push really started to get under way in the USA, conventional food producers expressed concern to the US Department of Agriculture (USDA) that the organic movement was seeking to increase market share by promoting bogus claims about its own products and misinformation about conventional practices. In response, the USDA, with support from the organic food industry, sought to clarify the then recently developed formulation of the organic marketing label. The Secretary of Agriculture had this to say in 2000:
Let me be clear about one thing. The organic label is a marketing tool. It is not a statement about food safety. Nor is ‘organic’ a value judgment about nutrition or quality.
Not surprisingly, though, these remarks have fallen on deaf years, and consumer surveys regularly show that organic food is perceived as healthier, safer and more nutritious, both in the US and elsewhere. Also, a study by the USDA’s Agricultural Marketing Service showed that people bought organic on the basis of the organic label or seal, rather than their understanding of the organic definition. Some 79% of those familiar with the seal could not identify the production standards behind the seal. As many independent observers have noted, the aggressive marketing of organic produce, with little concern for accuracy, has been the main driver of sales. US observers have also noted that the responsible regulators in terms of consumer protection and truth in advertising, namely the Food and Drug Administration (FDA) and the Federal Trade Commission (FTC) have been ineffective due to lack of resources and a lack of will to investigate vague and nebulous claims.
The organic food industry constantly plays on public fears in its marketing strategies, without necessarily telling outright lies. For example, a campaign by the USA’s Organic Trade Association, using the slogan ‘Organic, it’s worth it’ trumpeted the fact that “All products bearing the organic label must comply with federal, state, FDA, and international food safety requirements”, as if this wasn’t the case with conventional food. Similarly, Stonyfield Organic, a major US producer of organic foods, made a decision in August 2013 to add to the organic seal on their products the term ‘no toxic pesticides used here’, as if this marked them out from other food producers.
If we look beyond the aggressive marketing, which appears to be a mixture of deliberate misinformation and wishful thinking – a sort of naturalistic utopianism, – we find no clear evidence at all that organic food is either more safe or more nutritious than conventional food. The most comprehensive meta-analysis of these claims to date was published by Stanford University School of Medicine in September 2012. The study ‘did not find evidence that organic foods are more nutritious or carry fewer health risks than conventional alternatives’ (that’s a quote from the above-linked ‘Organic Marketing Report’).
The authors of the Organic Marketing Report have little to say about the broader environmental claims made by the organic food industry, because they’ve found from their own market research that the industry sees that health and safety concerns are the main drivers of consumer organic purchasing. So the focus of the industry has been on driving home the message that conventional food is unhealthy if not dangerous, and less nutritious. This message is succeeding in spite of a complete lack of scientific support. People should, I think, be more annoyed than they currently are about a campaign of exaggeration and misinformation that is in no way aligned to the evidence.
I should point out that, while many organic growers are sincere in their belief that they’re producing safer foods, the fact is that using ‘natural’ fertilisers and pesticides is not necessarily safer. David Waltner-Toews provides a salutary example in his excellently-titled book The Origin of Feces:
In spring 2011, a mutant, severely pathogenic, and antibiotic-resistant strain of E coli spread across 13 countries in Europe, sickening more than 3000 people and killing 48. The normal home for all E coli species, most of which are law-abiding, contributing members of society, is in the intestinal tracts of warm-blooded animals – that is, in excrement. This epidemic, however, was spread through fresh sprouts from an organic farm in Germany. The original contamination source was identified as fenugreek seeds from Egypt. The genetic make-up of the strain of E coli includes material last seen in sub-Saharan Africa.
Waltner-Toews isn’t trying to bag organic farming here – this is about the only mention he makes about organics in his book. As one of the world’s foremost experts on shit, or manure if you prefer, his concern is to educate us on the enormous complexity of the ‘shit cycle’, and its potential for harm as well as good. It’s a complexity that, I suspect, few commercial organic producers are aware of, though they’re dedicated to the idea that their naturally-fertilised produce is safer than conventional stuff. Sadly, food regulators have been conned into believing this, and organic foods, like naturopathic ‘medicines’, are nowhere near as rigorously checked and tested as their conventional counterparts. More than thirty years’ experience of studying manure and fecal-borne infections has convinced Waltner-Toews that these fecal-borne infections are becoming more frequent and more dangerous because global in their reach, due to the internationalism of modern agribusiness. The lack of monitoring of ‘organic’ production with its ‘safe’ natural fertilisers and pesticides is arguably a greater threat to global health than conventional production, which is well-regulated and heavily scrutinised, at least in the west.
environmental impact
Probably the most important claim made by the organic movement, though not as attention-grabbing as the health and safety claims, is that it is more sustainable and has less of an environmental impact than conventional farming and food production. This is, of course, a very difficult claim to analyse because of the enormous variations within conventional food production, but let’s look at some problems with the claim. First, if the organic marketeers succeed in their clear aim of taking over the world, there will be a problem of space. Small-scale backyard organic producers often con themselves into thinking ‘if I can do it, the world can’, but this is a false logic. In my own small backyard I’ve grown – ‘organically’ I suppose – lettuce and spinach and rocket and tomatoes and quinces and almonds and a whole range of herbs, and if I wasn’t such a slackarse I could produce much more, but the fact is that I work for a living, and increasingly my burgeoning neighbourhood is becoming stacked with medium to high-density housing for corporate types who have no time for gardening even if they had an interest, and they have no gardens to garden in anyway. And I suspect a high and growing percentage of these young corporate types would swear by ‘organic’ food. So just a clear-eyed view of the square kilometre or so around my home tells me feeding the multitude with organics would be quite a feat. As James Mitchell Crow reports, in the science magazine Cosmos, ‘Yields drop when switching to organic, and there isn’t enough organic fertiliser to go around anyway’. As long-time organic farmer Raul Adamchauk (one of the world’s foremost experts on organic farming) puts it:
The challenge for organic agriculture is to help solve the global issues of feeding people in the face of climate change and with increasing population… On some level, it becomes clear that organic agriculture isn’t going to do that by itself. No matter how you figure it, there aren’t enough animals making enough waste to fertilise more than a small fraction of the cropland that we need.
Much more land, therefore, would have to be dedicated to agriculture, with consequences for forestation and biodiversity – and then there’s the fertiliser problem. There are solutions, but the organic movement’s ideological negativity towards biotechnology will block them for the foreseeable future.
These global problems hold little interest, however, for most urban organic consumers. They’ve largely swallowed the negative message that conventional food is both unhealthy and environmentally damaging. For some, it’s part of a whole ideology of anti-modernity – the modern world is toxically chemical and we need to get back to nature.
But conventional food production, like science, never stands still. Over the past 50 years, during which the world’s population has doubled, food production has increased by 300%, though land taken up with such production has increased by only 12%. These astonishing statistics describe the results of the green revolution begun by Norman Borlaug in the sixties and still ongoing. The green revolution saved millions of lives, and could even be ‘blamed’ for contemporary obesity problems. Here are some more statistics: In 1960, the world’s population stood at just over 3 billion, and the average calorie consumption per person per day was 2189 (according to the UN Dept of Economic and Social Affairs). By 2010 the population was near 7 billion, and the average consumption had risen to 2830. Yields per hectare of rice, wheat, maize and other cereals have been spectacular, and these increases have been attributed more or less equally to improved irrigation, improved seeds and more effective synthetic fertiliser. There have been downsides of course, but biotechnological solutions, if they could be applied, would greatly improve the situation. They include not only pest-resistant and higher-yielding GMOs, but such exciting developments as precision agriculture, an automated agricultural system which restricts pesticide and fertiliser use to those areas of a crop that need them, reducing wastage to a minimum.
The green revolution has been far more beneficial than harmful, and the harms have been exaggerated by the ideologues and marketeers of the organic movement, but organic techniques have been effective in many areas, especially in low-tech farming. The real problem isn’t organic farming per se, it’s ideology, ignorance and sometimes downright dishonesty. Almost all the food we eat has been genetically modified – especially if you’re a vegetarian. It was through playing around with modifications and noting recessive and dominant traits in peas that Mendel discovered genes, that’s to say, he discovered just what it was that we’d been manipulating for millennia. We have transformed the food we eat to make it more tasty and filling and life-giving, though for centuries we barely knew what we were doing. The ‘nature’ that some of us want to go back to is entirely mythical. And we’re not being poisoned by our food, we’re too smart and determined to thrive for that.