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The value of organic farming

Organic farming again today. I’ve come across two papers from opposite ends of the world on this subject which it may be worth discussing together.

The first, from New Zealand, describes an experimental attempt to put a value on the ecosystem services provided by different pieces of arable land near Canterbury. That’s interesting – and difficult – enough, but the authors did this for both conventional farms and neighbouring organic farms. Values for the following services were calculated: biological control of pests, soil formation, mineralization of plant nutrients, pollination, services provided by shelterbelts and hedges, hydrological flow, aesthetics, food, raw materials (fibre, fuelwood, pharmaceuticals etc.), carbon accumulation, nitrogen fixation and soil fertility.

The results were that organic fields provided ecosystem services to the tune of US$ 4,600 per hectare per year, compared to US$ 3,680 for conventional fields: “there were significant differences between organic and conventional fields for the economic value of some ecosystem services.” Now, that must be associated with increased (agro)-biodiversity in the organic fields – more natural enemies, more pollinators, more earthworms, more medicinal plants etc. – but this was not measured in the study.

The other paper did compare diversity in organic and conventional farms, but only for plant at the species level, and no attempt was made to calculate values. Working in the south of England, the authors found significantly more plant diversity in organic arable fields as compared to conventional fields – though no differences in the plant diversity of other types of habitats within farms, such as woodland fragments and hedgerows.

I suppose what we need is a combination of these approaches, bringing together diversity assessment with valuation. Because in the end we’re only going to be able to conserve biodiversity if we can adequately value it.

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Seed appeal

This is a new one to me. Prof. Dr. Willem van Cotthem is asking his blog’s readers to donate spare seeds of melon, watermelon and pigeon pea. What’s more, he just wants the melon seeds you would otherwise throw away. Given how promiscuous most melons can be, the seeds are going to represent a bonanza of agricultural biodiversity.

This is why he wants the seeds:

All the seeds will be used for fruit production in arid or semi-arid regions, where we treat the soil with a water stocking soil conditioner, so that the rural people can grow these plants with a minimum of water. I promise to publish pictures on the results obtained with your seeds.

Isn’t this a very nice way to contribute to the success of a humanitarian project? The more melons and water melons you eat, the more poor rural people will get chances to grow them in their family garden and the kids will grow them in their school garden.

And the more varieties will be exposed to those testing conditions. I wonder what will emerge from the mix?

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Rice for diabetics launched

There’s a very odd story in The Hindu. It describes the launch of a “new variety of low glycemic rice“. Low glycemic foods are digested more slowly and create less of a spike in blood sugar, and have been pushed for diabetics, weight loss and sundry other benefits. One of the nice things about basmati rice, quite apart from its wonderful fragrance and flavour, is a relatively low glycemic index (although strictly speaking it has a medium GI). The new rice is not a basmati rice.

Moolgiri pack The rice, called Moolgiri, is marketed by Taj Mahal Agro Industries, and according to independent tests does indeed have a glycemic index of 54, just in the “low” category. That could be very interesting news, especially if Moolgiri is one of the many thousands of rice varieties that just happens to have this property. But the story got murkier the more I looked into it.

For a start, it is not a variety but a trade name. A rice with its own web site! There’s all kinds of information there, but not an awful lot about what exactly makes Moolgiri special. We learn that:

Moolgiri rice is a clear blend of tradition and technology. After ten years of continuous research Tajmahal Agro industries identified suitable traditional grain and developed innovative process to achieve Moolgiri.

There’s also a lot about how it is grown, tested and so on. But you have to dig deeper to discover that the variety itself is called manisamba, and that it

undergoes a patented process to remove 70% of the starch content.

So I did a little more digging, in SINGER, and discovered that there is a rice called Pamani samba, that it was collected in India, and that there is a sample (of unknown status) in the genebank at the International Rice Research Institute. And there the trail goes cold. There seems to be no further information about this wonderful variety. No “special traits” are noted.

All of which is both satisfying and unsatisfying (rather like a meal of high GI rice?). I found the variety. But no more about it. Maybe the special patented process could do the same to any old rice? I doubt it, but you never know. And maybe there are actually rice varieties out there that would have a low GI without a special patented process. I think that’s what I had been hoping, that there existed a rice that, polished and purified, would be have a naturally low glycemic index. Alas, it ain’t so.

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The best bee paper ever … for now

What’s Killing American Honey Bees? by Benjamin P. Oldroyd, an Australian entomologist, is without a doubt the best summary of the current state of play on Colony Collapse Disorder. I know I’m biased, being — gasp — a scientist, but Oldroyd’s paper is the bees’ knees. It has hypotheses (wot, no mobile phones?), facts, and interpretations. And one rather interesting conclusion. I’ll let Oldroyd explain:

Remarkably, honey bees maintain the temperature of their brood nest within ± 0.5 °C of 34.5 °C, despite major fluctuations in ambient temperature. If the brood is incubated a little outside this range, the resulting adults are normal physically, but show deficiencies in learning and memory. Workers reared at suboptimal temperatures tend to get lost in the field, and can’t perform communication dances effectively. Although entirely a hypothesis, I suspect that if colonies were unable to maintain optimal brood nest temperatures, CCD-like symptoms would be apparent.

… snip …

I suggest that another possible cause of CCD might simply be inadequate incubation of the brood. Thus any factor—infections, chronic exposure to insecticides, inadequate nutrition, migration in adult population, and inadequate regulation of brood temperature might cause CCD-like symptoms.

My hypothesis could be easily tested by removing brood from several colonies and incubating some of it at optimal temperature and some at suboptimal temperature. The brood would then be used to constitute new colonies in which some colonies comprise workers raised at low temperature and some comprise workers raised at optimal temperature. I predict that the colonies comprising workers reared at suboptimal temperature will show signs of CCD. Moreover, I would not be surprised if they showed higher levels of stress-related viral infections. These effects could act synergistically—more virus leads to shorter-lived, less efficient workers, that in turn leads to suboptimal temperature regulation, and more short-lived bees.

See, kids, that’s the way science is done. But really, go read the article. And if there’s anything in it you honestly don’t follow, ask.

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Ecotourism investigated

From id21, a report that questions some of the assumptions about ecotourism, and asks whether it really is an innovative conservation and development strategy or merely a celebration, by those who can afford it, of poverty?

Ecotourism projects tell communities they can generate revenue by protecting biodiversity, but also that they should never hope to achieve much beyond this role. This ties the development prospects of rural communities to local, natural limits in a way that is completely alien to economic development in richer societies.

Given that the author, Jim Butcher, takes a pretty dim view of the whole scene, I suppose I should be glad that he does not seem to recognize agricultural ecotourism at all. But there are strong suggestions that this can help communities not only to gain an income but also to preserve their traditional knowledge at the same time as making the modern development steps needed to connect to the wider world. (There is a method for commenting on the id21 site, but it seems awfully cumbersome, and I can’t actually see whether anyone has commented on Butcher’s piece.)