But, I have nearly finished uni for the year, and I have several recipes and other bits and pieces planned for here.
Watch this space!
Thursday, 9 April 2009
Tuesday, 17 March 2009
An essay about hops
What Do Historical Evidence and Modern Clinical Trials Tell Ethnopharmacologists About The Usefulness Of Hop Alpha and Beta Acids As A Tool In The Fight Against Antibiotic Immunity?
Hops have been cultivated and used from around the 10th century (Delyser,1994) and have been viewed as ‘a wicked weed that would spoil the taste of the drink (beer) and endanger the people’ in Henry VIII’s time (Hornsey, 2003) to being carefully ‘cultivated for the sole interest of the brewing industry’ (Alfa- Laval, 1983). They have also had a long association with having a medicinal effect, most interestingly their antibacterial and sedative properties have been noted as far back as 4000 years (Simpson et al, 1992). Antibiotic resistance is one of the biggest problems facing the medical world with a massive increase in the past two decades of drug resistant strains bacteria such as MRSA. I will argue in this essay that, while not a hugely potent antibacterial agent, hop acids have a place in the fight against antibiotic resistance. I will do this by detailing the history of hop use focusing on brewing, evidence from other species, clinical research in humans and examining the causes of antibiotic immunity. I will focus other two main compounds active in hops that have an antibacterial effect, and a common isomer of one of them.
The hop is a genus of flowering bines, native to the temperate European and
American areas. Female flowers of the hop bine are called cones; it is in these cones that the hop oils containing the active ingredients are held. The hop is part of the family Cannabaceae, which also includes the genusCannabis (Greive, 1972). There is evidence of hops being used as a preservative in beer since the 1500’s (Hornsey, 2003) although it’s use was not universally approved of. Henry VIII famously claimed they were little more than a ‘weed’, which ‘spoiled the taste (of beer)’ (Hornsey, 2003) this statement is true to a certain extent. Due to their climbing nature and rhizomic spreading it is possible for hop bines to overrun a cultivated area, suffocating other plants
Traditionally many different herbs and plants were added as a flavouring to beer however, it was noticed that when hops were added to a beer it lasted longer (Behre, 1998). This was due to the fact that the α and β acids allowed the growth of yeast, but killed other bacteria by disintegrating phospholipid bilayer cell membranes (Teuber et al, 1972 and Teuber, 1970). Around the same period the rise of Britain as a seafaring nation required the storage of drinkable water for long periods at sea, which at the time was unfeasable. Beer kept for a much longer period of time and so was used as the main source of drinking water for sailors of the time. This weak, low gravity beer became known as ‘small beer’ (Behre, 1998). As the length of time at sea increased, so did the alcohol and hop content of beer. During the colonisation of India by the British India Pale Ale was born, this contained the highest levels of hops ever seen in a beer so it survived the long sea journey. It became so popular it was eventually only brewed for internal consumption (Spring et al, 1977).
As with all medicinal plants there are many chemicals that potentially have an effect on the body, including methylbutenol which induces a mild sedative effect, and a chemical; 8-Prenylnaringenin which mimics the action of oestrogen (Pratt et al, 2004, Takamura-Enya et al, 2003 and Beuchat et al 1989).
The active compounds I wish to closer examine however, are the α acid humulone which has the chemical formula C12H30O5 and the β acid lupulone which has the chemical formula C26H35O4. Due to extensive research carried out by brewers we now know humulone is not a single chemical compound but rather a mixture of 3 closely related compounds called humulone, adhumulone and cohumulone (Alpha-Laval, 1983). When hops are boiled during the beermaking process the components of the humulone and lupulone are isomerised to create the complexes: isohumulone, isoadhumulone, isocohumulone, isolupulone, isoadlupulone and isocolupulone (Alfa-Laval, 1983) . It is these compunds that give beer it’s bitter flavour and the isohumulone that has an antibacterial effect (Delyser et al, 1994).
Many antibiotic compounds are used by doctors to aid the fight against unwanted bacteria in our bodies, due to abuse of these substances however bacteria are able to evolve immunity from them, rendering them useless. It is often described as a ‘medical arms race’ between bacteria and the developers of antibiotics (Burke, 1998). As successive generations of bacteria are generated, mutations within their DNA that favour resistance to certain antibiotics are selected for, ultimately rendering the antibiotic useless. This has a massive impact on the way in which doctors now prescribe antibiotics and the instructions given to patients on how they must finish the course (Cirz et al, 2005). The problem with people not finishing a course of antibiotics is that it causes a bottleneck in the population of the bacteria, allowing the more resistant genes to be passed on to future generations. If this happens several times it is possible within the scale of a few years to develop a resistance (Burke, 1998).
Penicillin resistance was first found in 1947 a mere four years after the drug was commercially introduced. Methicillin, a similar antibiotic to penicillin has developed a resistant form of Staphylococcus Aureus known as MRSA. The first note of this resistant strain in the U.K. was in 1961 (Maple et al, 1989) and is now ‘quite common’ in hospitals (Levy, 2000). According to Levy’s analysis ‘MRSA was responsible for 37% of fatal cases of blood poisoning in
the UK in 1999, up from 4% in 1991. Half of all S. aureus infections in the US are resistant to penicillin, methicillin, tetracycline and erythromycin’ (Levy, 2000).
A key problem within human antibiotic resistance is that due to the feeding of antibiotics to farm animals a constant low level of antibiotic is ingested . This base level aids the development of resistant strains of certain bacteria (Sapkota et al, 2007). The need to feed antibiotics to animals from birth is caused by the intensive farming methods used in many countries, examples of which include battery hens and caged pigs. In these cramped quarters it is easy for infection to spread quickly, potentially killing a large proportion of a farmer’s livestock (Castanon, 2007). For many hundreds of years livestock, especially pigs due to their omnivorous nature have been fed the spent hops and yeast from the brewing process (Brorson et al, 2002). It was noted these animals were generally in better health than those not fed brewing waste products (Delyser et al, 1994).
Due to this, there have been clinical trials run mainly on battery hens in which by adding spent hops to their diet show similar effects to antibiotic administration (Cornelison et al, 2006 and Pizarski, 2005). Further to this, more research on human subjects has been undertaken to discover how hop acids may help fight infection. Natarajan et al discuss a positive antibacterial co-action between hops and selected antibiotics when used to fight several different bacteria (Natrajan et al, 2007). Ohsugi et al also discuss that they were able to significantly reduce the levels of Helicobacter pylori, a stomach bacterium linked with chronic inflammation, ulceration and cancer (Ohsugi et al, 2007).
Despite this the there are no pharmaceutical companies working on hops as an antibacterial product, which in my opinion is an oversight based on the evidence that is present both clinically and historically. People may choose to self medicate with hops to fight minor infections but this is problematic in that there are other active chemicals as mentioned previously. Men may develop swelling of the breast tissue, reduced sperm count and emotional instability (Thuille et al, 2003).
This further adds weight to the argument that the acids themselves need to be isolated and used so as to reduce side effects. It is well noted that the old, ill and the young are particularly susceptible to infection form bacteria such as MRSA. Would it be possible to dose these
individuals with a base level of these acids to avoid infection as demonstrated in livestock? I feel more research is needed. In conclusion, both clinical trials and historical evidence show a strong case for the commercial development of α and β acids extracted from hops. History and clinical trials prove their ability as an antibacterial agent There are potentially many practical applications for their antibacterial effects including in animal feeds as a less aggressive form of disease control. There are also applications In humans to provide a baseline protection against antibiotic resistant strains of bacteria. I however feel that much research is needed into these compounds before any sort of pharmaceutical product becomes available.
Bibliography
Alfa-Laval, 1983. A Brewery Handbook. Alfa-Laval Press. London.
Behre K E., 1999. The history of beer additives in Europe - a review. Vegetation History and Archaeobotany 8, 35-48. Beuchat R., Golden D A., 1989. Antimicrobials Occurring Naturally in Foods. Food Technology, Institute of Food Technologists 43, 134-142.
Burke T., 1998. Antibiotic Resistance—Squeezing the Balloon? Journal of the American Medical Association 280, 1270-1271.
Brorsen W., Lehenbauer T., Ji D., Connor J., 2002. Economic Impacts of BanningSubtherapeutic Use of Antibiotics in Swine Production. Journal of Agricultural and Applied Economics 34, 489-500.
Castanon J I., 2007. History of the use of antibiotic as growth promoters in European poultry feeds. Poultry Science 86, 2466–2471.
Cirz R T., Chin J K., Andes D R., de Crécy-Lagard V., Craig W A., Romesberg F E., 2005. Inhibition of mutation and combating the evolution of antibiotic resistance. Public Library of Science Biology 3, 176-179.
Cornelison J M., Yan F., Watkins S., Lloyd Rigby S., Segal J., Waldroup P., 2006. Evaluation of Hops (Humulus iupulus) as an Antimicrobial in Broiler Diets. International Journal of Poultry Science 5, 134-136.
Delyser D Y., Kasper W J., 1994. Hopped Beer: The Case for Cultivation. Economic Botany 48, 166-170.
Greive M., 1972. A Modern Herbal Vol. 1. Dover Publications. New York
Hornsey I., 2003. A History of Beer and Brewing. Royal Society of Chemistry. London.
Levy S B., 2000. Antibiotic and antiseptic resistance: impact on public health. The Pediatric Infectious Disease Journal 34, 142-145.
Maple P., Hamilton-Miller J., Brumfitt W., 1989. World-wide antibiotic resistance in methicillin-resistant Staphylococcus aureus. The Lancet 111, 537-540.
Natarajan S., Katta I., Andrei V., Babu Rao Ambati M., Leonida G., 2007. Positive antibacterial co-action between hop (Humulus lupulus) constituents and selected antibiotics. Phytomedicine 15, 194-201.
Ohsugi M., Kadota S., Ishii E., Tamura T., Okamura Y., 2007. Antibacterial activity of traditional medicines and an active constituent lupulone from Humulus lupulus against Helicobacter pylori. Phytomedicine 15, 194-201.
Pisarski R K., Ziehook M., 2005. The influence of herbs on haematological indicators in broiler chickens. Animal Science Papers and Reports 12 234-239.
Pratt S., Matthews K., 2004. SuperFoods. HarperCollins Books, New York.
Sapkota A R., Lefferts L Y., McKenzie S., Walker P., 2007. What do we feed to food-production animals? A review of animal feed ingredients and their potential impacts on human health. Environmental Health Perspectives 115, 663–670.
Simpson W J., Smith A R., 1992. Factors affecting antibacterial activity of hop compounds and their derivatives. Journal of Applied Bacteriology 72, 327-334.
Spring J., Buss D., 1977. Three centuries of alcohol in the British diet. Nature 270, 567-572.
Takamura-Enya J., Ishihara S., Tahara S., Goto Y., Totsuka T., Sugimura K., Wakabayashi 2003. Analysis of estrogenic activity of foodstuffs and cigarette smoke condensates using a yeast estrogen screening method. Food and Chemical Toxicology 41, 543-550.
Teuber M., Schmalreck A F., 1973. Membrane leakage in Bacillus subtilis 168 induced by the hop constituents lupulone, humulone, isohumulone and humulinic acid. Archives of Microbiology 94, 159-171.
Teuber M., 1970. Low Antibiotic Potency of Isohumulone. Applied Environmental Microbiology 19, 871.
Thuille N., Fille M., Nagl M., 2003. Bactericidal activity of herbal extracts. International Journal of Hygene and Environmental Health 206, 217–221.
Monday, 16 March 2009
Cassoulet
I love cassoulet, it is easy to make and, as with many good recipes it has many local variations. It is a real French one pot peasant meal, which means that depending on how flush you are feeling it can be either a cheap dinner that is bulked out with lots of beans or an opulent feast full of duck!
This recipe as with all recipes, is not a definative version, play around with it until it is to your liking. I'm a sucker for lots of garlic and smoky Toulouse sausage in mine, but it is just a case of personal taste. This recipe is a more everyday version without the duck in but, for 4 people half the amount pork and add one cooked duck leg per person.
This recipe is ideally cooked in an ovenproof casserole such as a Le Creuset but can be cooked on the top at a pinch.
Prep time: About 20 minutes
Cooking time: About 2 hours
For 4 people you will need:
One large onion, chopped roughly
4 large cloves of garlic, chopped roughly
2 bay leaves
4 Toulouse sausages, sliced into chunks about 1cm thick (www.wealdsmokery.co.uk do ace ones, but most supermarkets sell some sort of smoked garlic sausage which will work)
2 cans of haricot beans, drained and rinsed in fresh water
About 400g of pork fillet roughly diced
2 tins of chopped tomatoes
A splash of white wine
Half a tube of concentrated tomato paste
Method
1. Fry the chopped onion in a little olive oil until soft and slightly browned.
2. Add the garlic and fry until cooked.
3. Remove the onion and garlic and add a little more oil to the pan. Turn up the heat
4. Add the diced pork and seal the pork all over giving it a little colour.
5. Place the onions and garlic back in the pan and deglaze it with a good slug of white wine.
6. Add the Toulouse sausage, beans, tomatoes, tomato concentrate and bay leaves.
7. Get the mixture up to the boil and place in an oven at 180degC for about 2 hours.
8. Check it and give it a stir every half hour or so, if it looks a little dry add a splash more white wine.
This needs nothing more to be served with than a good bit of crusty French bread and a glass of white wine or your favorite beer (something like Budvar or any other Czech style lager is an awesome combo with pork cooked like this).
This recipe as with all recipes, is not a definative version, play around with it until it is to your liking. I'm a sucker for lots of garlic and smoky Toulouse sausage in mine, but it is just a case of personal taste. This recipe is a more everyday version without the duck in but, for 4 people half the amount pork and add one cooked duck leg per person.
This recipe is ideally cooked in an ovenproof casserole such as a Le Creuset but can be cooked on the top at a pinch.
Prep time: About 20 minutes
Cooking time: About 2 hours
For 4 people you will need:
One large onion, chopped roughly
4 large cloves of garlic, chopped roughly
2 bay leaves
4 Toulouse sausages, sliced into chunks about 1cm thick (www.wealdsmokery.co.uk do ace ones, but most supermarkets sell some sort of smoked garlic sausage which will work)
2 cans of haricot beans, drained and rinsed in fresh water
About 400g of pork fillet roughly diced
2 tins of chopped tomatoes
A splash of white wine
Half a tube of concentrated tomato paste
Method
1. Fry the chopped onion in a little olive oil until soft and slightly browned.
2. Add the garlic and fry until cooked.
3. Remove the onion and garlic and add a little more oil to the pan. Turn up the heat
4. Add the diced pork and seal the pork all over giving it a little colour.
5. Place the onions and garlic back in the pan and deglaze it with a good slug of white wine.
6. Add the Toulouse sausage, beans, tomatoes, tomato concentrate and bay leaves.
7. Get the mixture up to the boil and place in an oven at 180degC for about 2 hours.
8. Check it and give it a stir every half hour or so, if it looks a little dry add a splash more white wine.
This needs nothing more to be served with than a good bit of crusty French bread and a glass of white wine or your favorite beer (something like Budvar or any other Czech style lager is an awesome combo with pork cooked like this).
Friday, 27 February 2009
Good News for Kentish Food
Seems like i'm living in a good area for food!
http://www.telegraph.co.uk/travel/foodandwineholidays/4539236/Restaurants-Culinary-paradise-found...in-East-Kent.html
http://www.telegraph.co.uk/travel/foodandwineholidays/4539236/Restaurants-Culinary-paradise-found...in-East-Kent.html
Wednesday, 25 February 2009
Beer Tasting
I am a keen real ale drinker not to worry though, although I have a beard I don't have beige cords, or an wool Arran jumper. I think it important that more young people start drinking real ale rather than the chemically, cold, mass produced fizzy shite on offer most places. Don't get me wrong, there is nothing more satifying than cracking open an ice cold lager beaded with condensation on a hot summer day, I just prefer ale.
Reading Mark Dredge's Pencil&Spoon beer blog has kicked my arse into action to do some beer tasting. I haven't done a tasting for you yet so I went out to the supermarket and got a nice selection of beers, along with a couple I had in my cupboard already. I tried to buy mainstream beers easily available to all with a slight bias to those brewed in the South East. Each beer is reated out of 5 stars
Hopefully it will give you an introduction to some beers you might like to try.
Sharps Doom Bar
Brewed in Cornwall, Doom bar pours with an amber colour and has an creamy coloured head that does not last long. In the glass it has a strong caramel/toffee smell with a fresh hoppy/grassy smell. It is creamy in the mouth with more toffee which is cut through by a punch of bitter hop which lingers in the mouth. At 4% it makes for a beer you could happily drink all night. ****
Hog's Back T.E.A. (Traditional English Ale)
Brewed on the South Downs in Surrey this beer has quite a dark colour for a T.E.A., it has a large creamy head that lasts. In the glass it is a little underwhelming, with hints of the hops and a slight burnt toasty smell. It is similar in the mouth, not much malt is present but there are plenty of hops present. A decent enough beer, just a little dull. ***
Shepherd Neame Spitfire
Brewed in Faversham in Kent, this beer pours a barely-sugar colour with an off-white head. In the glass it has strong vanilla and toffee malt notes and spice. it is quite big feeling in the mouth, but is slightly over carbonated in the bottle. It has fruit and a slight toasty note. A good beer better enjoyed on draught. ****
Goachers Shipwrecked
Brewed in Maidstone and only available on draught at the Shipwright's Arms at Hollow Shore (Speak nicely to Derek the landlord and he will let you take a 4 pint container home). The beer pours with a dark tan colour and has a thin white head. In the glass it is hoppy with a biscuity note. In the mouth it feels thin but smooth and refreshing, very little malt is present but there are plenty of dry hops making it my session beer of choice. *****
Innis and Gunn Oak Aged beer
Brewed in Edinborough and aged in oak barrels, this beer is a dark golden colour with a creamy white head. In the glass it has masses of different aromas: vanilla, toffee, and grassy hops. In the mouth this is even more obvious, a lovely buttery mouthfeel with huge punches of vanilla, toffee with plenty of sweetness cut through by the hops. A lovely innovative beer but at 6.6% you wouldn't want to drink much of it! ****
Otter Brewey Bright
Brewed in Devon, Otter Bright is a pale beer, with a golden colour and a very thin white head. In the glass there are floral notes along with with a hint of pear drops. In the mouth it is medium-bodied, very clean and smooth. It has crisp apple and sweet pear tastes and a gentle hoppiness with a slight citrussy finish. A nice light summery beer. ****
Have a go at a tasting yourself, why not get a few mates round with half a dozen beers and see what you all think. When it comes to deciding on what flavours are present I find this diagram really helpful:
Have some fun!
Reading Mark Dredge's Pencil&Spoon beer blog has kicked my arse into action to do some beer tasting. I haven't done a tasting for you yet so I went out to the supermarket and got a nice selection of beers, along with a couple I had in my cupboard already. I tried to buy mainstream beers easily available to all with a slight bias to those brewed in the South East. Each beer is reated out of 5 stars
Hopefully it will give you an introduction to some beers you might like to try.
Sharps Doom Bar
Brewed in Cornwall, Doom bar pours with an amber colour and has an creamy coloured head that does not last long. In the glass it has a strong caramel/toffee smell with a fresh hoppy/grassy smell. It is creamy in the mouth with more toffee which is cut through by a punch of bitter hop which lingers in the mouth. At 4% it makes for a beer you could happily drink all night. ****
Hog's Back T.E.A. (Traditional English Ale)
Brewed on the South Downs in Surrey this beer has quite a dark colour for a T.E.A., it has a large creamy head that lasts. In the glass it is a little underwhelming, with hints of the hops and a slight burnt toasty smell. It is similar in the mouth, not much malt is present but there are plenty of hops present. A decent enough beer, just a little dull. ***
Shepherd Neame Spitfire
Brewed in Faversham in Kent, this beer pours a barely-sugar colour with an off-white head. In the glass it has strong vanilla and toffee malt notes and spice. it is quite big feeling in the mouth, but is slightly over carbonated in the bottle. It has fruit and a slight toasty note. A good beer better enjoyed on draught. ****
Goachers Shipwrecked
Brewed in Maidstone and only available on draught at the Shipwright's Arms at Hollow Shore (Speak nicely to Derek the landlord and he will let you take a 4 pint container home). The beer pours with a dark tan colour and has a thin white head. In the glass it is hoppy with a biscuity note. In the mouth it feels thin but smooth and refreshing, very little malt is present but there are plenty of dry hops making it my session beer of choice. *****
Innis and Gunn Oak Aged beer
Brewed in Edinborough and aged in oak barrels, this beer is a dark golden colour with a creamy white head. In the glass it has masses of different aromas: vanilla, toffee, and grassy hops. In the mouth this is even more obvious, a lovely buttery mouthfeel with huge punches of vanilla, toffee with plenty of sweetness cut through by the hops. A lovely innovative beer but at 6.6% you wouldn't want to drink much of it! ****
Otter Brewey Bright
Brewed in Devon, Otter Bright is a pale beer, with a golden colour and a very thin white head. In the glass there are floral notes along with with a hint of pear drops. In the mouth it is medium-bodied, very clean and smooth. It has crisp apple and sweet pear tastes and a gentle hoppiness with a slight citrussy finish. A nice light summery beer. ****
Have a go at a tasting yourself, why not get a few mates round with half a dozen beers and see what you all think. When it comes to deciding on what flavours are present I find this diagram really helpful:
Have some fun!
Monday, 2 February 2009
A recipe for you all!
Having stumbled on Pete Brown's Beer blog (http://petebrown.blogspot.com) It has stirred me into publishing a recipe in which beer is the key ingredient! So here we are:
Pete's Guinness Carbonade of Beef - Serves 4
Ingredients:
450g Braising Steak
Two large chopped onions
Two chopped cloves of garlic
250ml of Guinness
A beef stock cube
A Tablespoon of plain flour
A little olive oil
Method:
1. Chop the onions in half then chop into half ring shapes (it is important to get them all to roughly the same thickness so that they cook evenly). Add the onins to an ovenproof casserole and fry in a little olive oil until soft.
2. Remove the onions and turn up the heat. When the casserole is really hot, seal the cubed braising steak until the meat is brown all over. Don't worry if the pan catches a little on the bottom, this will all add to the flavour!
3. Return the onions to the casserole and add the garlic. Continue to fry for a couple of minutes. Be careful not to burn the garlic as it will turn bitter. Add the flour and stir thoroughly to break up any big lumps.
4. Boil a little water in the kettle and dissolve the stock cube. Add the stock and the Guinness to the casserole dish and bring to the boil.
5. When boiling put the lid on the casserole and place in a preheated oven at 170C for about 2 hours.
6. Check every half hour while cooking that there is enough liquid in the casserole. If not add a little more Guinness.
7. Serve with mashed potatoes, leeks and carrots.
Pete's Guinness Carbonade of Beef - Serves 4
Ingredients:
450g Braising Steak
Two large chopped onions
Two chopped cloves of garlic
250ml of Guinness
A beef stock cube
A Tablespoon of plain flour
A little olive oil
Method:
1. Chop the onions in half then chop into half ring shapes (it is important to get them all to roughly the same thickness so that they cook evenly). Add the onins to an ovenproof casserole and fry in a little olive oil until soft.
2. Remove the onions and turn up the heat. When the casserole is really hot, seal the cubed braising steak until the meat is brown all over. Don't worry if the pan catches a little on the bottom, this will all add to the flavour!
3. Return the onions to the casserole and add the garlic. Continue to fry for a couple of minutes. Be careful not to burn the garlic as it will turn bitter. Add the flour and stir thoroughly to break up any big lumps.
4. Boil a little water in the kettle and dissolve the stock cube. Add the stock and the Guinness to the casserole dish and bring to the boil.
5. When boiling put the lid on the casserole and place in a preheated oven at 170C for about 2 hours.
6. Check every half hour while cooking that there is enough liquid in the casserole. If not add a little more Guinness.
7. Serve with mashed potatoes, leeks and carrots.
Thursday, 22 January 2009
Why organic food can’t feed the World
Recent studies have re-visited the idea that organic methods of agriculture would be sufficient to feed the world – but they are flawed because of their naïve views about agriculture in developing nations
A recent study, published in the journal Renewable Agriculture and Food Systems provides new data that suggests it can. However, I have some grave reservations about this. The authors of this study assume the major stumbling blocks to organic farming feeding the world are low crop yields and insufficient quantities of approved organic fertilisers. There are however, in my opinion other other hurdles that need to be dealt with first.
Green Revolution
Bangladesh is the size of England and Wales together, but with a of about 140 million people. It has achieved remarkable progress in its food productivity, even achieving self-sufficiency in flood-free years. The basis of the Green Revolution that saved South Asia was not organics, but the use of a dwarfing gene to stop rice and wheat collapsing when they flourished, coupled with chemical fertilisers and irrigation systems.
Despite the burgeoning population, the Green Revolution of the 1960s is continuing today in South Asia with an increase in the use of hybrid rice and maize, conservation agriculture, deep placement of nitrogen in rice paddies, and many other exciting, new technologies.
Heavy burden
So, why won't the use of pure organics work in developing countries like Bangladesh?
Most supporters of the idea that organic farming can feed the world, assume that organic manures are cheap and available to all – even the poor. But this isn't often the case. Cow dung in Bangladesh and almost all of South Asia is a valuable commodity. It is collected largely by women and children and used as fuel. It's found in nearly every house, dried and formed into patties, to be sold or burned for cooking.
Straw is another organic source of nutrients, but that's not always available either. Rice and wheat straw is collected from the fields, and used for cattle feed or thatching for roofs. Even the stubble is used, which the poorest use for fuel.
The authors of the study mentioned above, led by researchers at the University of Michigan in Ann Arbor, have rightly assumed that organics can supply sufficient nutrients for plant growth. However, the quantities of organics required to sustain such productive growth makes it very difficult for the poor to handle. Organics whether farmyard manure, compost, or cow dung, contain moisture and are heavy and difficult to carry from the homestead to the fields by the growers.
For example, to produce a six-tonne rice crop in the peak season requires 100 kg of nitrogen. Because of monsoons and the fact that several metres of rainfall drains through the soil every three months, the amount of nitrogen it carries is low. Assuming good quality manure was used, there would be about 0.6 per cent nitrogen in the material; thus, requiring 17 tonnes per hectare to produce a six-tonne rice yield.
Can you imagine carrying 17 tonnes of manure, in repeated 50 kilogram loads, in a basket on your head? The lack of machinery to carry that material and the labour required to apply it, compounds the challenge.Plus, there just simply isn't enough manure, or even plant biomass, available to apply 17 tonnes per hectare, for even a single annual rice crop across the whole of Bangladesh. That's enough of a problem, but when you consider there are actually two rice crops a year, the full scale of the problem becomes apparent!
Green manure
In answer to some of these problems, the new study proposes the use of a leguminous 'green manure' crop. These pulse crops fix nitrogen into the soil from the air through a symbiotic relationship with bacteria in their roots. They provide enough nitrogen for their own growth and more, and when ploughed under provide nitrogen for a subsequent crop too.
However for such a crop to be used in Bangladesh, it would have to take the place of a food crop, effectively halving the amount of food the land can provide. The cropping intensity in many developed countries is well over two crops per year, as many as four to five crops per year in places that are elevated and flood-free are feasible.
Besides substituting for a food crop, green manure crops would also require cutting and ploughing under the soil. While ploughing technology has increased dramatically in the last decade in many developed countries, it is mostly the two-wheel tractors or roto-tiller types; thus making it a significant challenge to plough down any high-biomass green manure or crop residues into the soil.
Some propose a greater use of leguminous food crops to supply nitrogen for the proceeding cereal crop and where possible, growers would love to expand pulses. However, in South Asia, while the national pulse yields appear stable, switching to more of these crops is quite risky for individual farmers due to unseasonable rainfall, diseases, and poor growing environments.
Faced with a choice
So, to make compost effectively, one has to have surplus plant biomass and cow dung. For the poor who have limited land and animals, this is quite difficult.
Surveys conducted in Bangladesh clearly show that growers that do have the ability to add organics to their land are those who are richer, have larger land holdings and own animals. The poor have to rely on purchased fertilisers, whether organic or chemical. When faced with a choice based on labour and expense, the poor choose the non-organic fertilisers.
Another recent study, published in Nature, revealed clearly what plant scientists have known for years — that plants take up some 20+ elements from the soil — whether it is from decomposing organics or chemical fertilisers. That study showed there was absolutely no difference in the biochemical make up of the plants grown in pure organics compared to fertilisers.
Can organic agriculture feed the world? No, but most growers understand that it benefits the soil, and as such its use is is advocated as much as is possible. Unfortunately, for Bangladesh, and many developing countries, those possibilities are diminishing yearly as organics become less and less available and affordable.
A recent study, published in the journal Renewable Agriculture and Food Systems provides new data that suggests it can. However, I have some grave reservations about this. The authors of this study assume the major stumbling blocks to organic farming feeding the world are low crop yields and insufficient quantities of approved organic fertilisers. There are however, in my opinion other other hurdles that need to be dealt with first.
Green Revolution
Bangladesh is the size of England and Wales together, but with a of about 140 million people. It has achieved remarkable progress in its food productivity, even achieving self-sufficiency in flood-free years. The basis of the Green Revolution that saved South Asia was not organics, but the use of a dwarfing gene to stop rice and wheat collapsing when they flourished, coupled with chemical fertilisers and irrigation systems.
Despite the burgeoning population, the Green Revolution of the 1960s is continuing today in South Asia with an increase in the use of hybrid rice and maize, conservation agriculture, deep placement of nitrogen in rice paddies, and many other exciting, new technologies.
Heavy burden
So, why won't the use of pure organics work in developing countries like Bangladesh?
Most supporters of the idea that organic farming can feed the world, assume that organic manures are cheap and available to all – even the poor. But this isn't often the case. Cow dung in Bangladesh and almost all of South Asia is a valuable commodity. It is collected largely by women and children and used as fuel. It's found in nearly every house, dried and formed into patties, to be sold or burned for cooking.
Straw is another organic source of nutrients, but that's not always available either. Rice and wheat straw is collected from the fields, and used for cattle feed or thatching for roofs. Even the stubble is used, which the poorest use for fuel.
The authors of the study mentioned above, led by researchers at the University of Michigan in Ann Arbor, have rightly assumed that organics can supply sufficient nutrients for plant growth. However, the quantities of organics required to sustain such productive growth makes it very difficult for the poor to handle. Organics whether farmyard manure, compost, or cow dung, contain moisture and are heavy and difficult to carry from the homestead to the fields by the growers.
For example, to produce a six-tonne rice crop in the peak season requires 100 kg of nitrogen. Because of monsoons and the fact that several metres of rainfall drains through the soil every three months, the amount of nitrogen it carries is low. Assuming good quality manure was used, there would be about 0.6 per cent nitrogen in the material; thus, requiring 17 tonnes per hectare to produce a six-tonne rice yield.
Can you imagine carrying 17 tonnes of manure, in repeated 50 kilogram loads, in a basket on your head? The lack of machinery to carry that material and the labour required to apply it, compounds the challenge.Plus, there just simply isn't enough manure, or even plant biomass, available to apply 17 tonnes per hectare, for even a single annual rice crop across the whole of Bangladesh. That's enough of a problem, but when you consider there are actually two rice crops a year, the full scale of the problem becomes apparent!
Green manure
In answer to some of these problems, the new study proposes the use of a leguminous 'green manure' crop. These pulse crops fix nitrogen into the soil from the air through a symbiotic relationship with bacteria in their roots. They provide enough nitrogen for their own growth and more, and when ploughed under provide nitrogen for a subsequent crop too.
However for such a crop to be used in Bangladesh, it would have to take the place of a food crop, effectively halving the amount of food the land can provide. The cropping intensity in many developed countries is well over two crops per year, as many as four to five crops per year in places that are elevated and flood-free are feasible.
Besides substituting for a food crop, green manure crops would also require cutting and ploughing under the soil. While ploughing technology has increased dramatically in the last decade in many developed countries, it is mostly the two-wheel tractors or roto-tiller types; thus making it a significant challenge to plough down any high-biomass green manure or crop residues into the soil.
Some propose a greater use of leguminous food crops to supply nitrogen for the proceeding cereal crop and where possible, growers would love to expand pulses. However, in South Asia, while the national pulse yields appear stable, switching to more of these crops is quite risky for individual farmers due to unseasonable rainfall, diseases, and poor growing environments.
Faced with a choice
So, to make compost effectively, one has to have surplus plant biomass and cow dung. For the poor who have limited land and animals, this is quite difficult.
Surveys conducted in Bangladesh clearly show that growers that do have the ability to add organics to their land are those who are richer, have larger land holdings and own animals. The poor have to rely on purchased fertilisers, whether organic or chemical. When faced with a choice based on labour and expense, the poor choose the non-organic fertilisers.
Another recent study, published in Nature, revealed clearly what plant scientists have known for years — that plants take up some 20+ elements from the soil — whether it is from decomposing organics or chemical fertilisers. That study showed there was absolutely no difference in the biochemical make up of the plants grown in pure organics compared to fertilisers.
Can organic agriculture feed the world? No, but most growers understand that it benefits the soil, and as such its use is is advocated as much as is possible. Unfortunately, for Bangladesh, and many developing countries, those possibilities are diminishing yearly as organics become less and less available and affordable.
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