A Pictorial Essay on Rapeseed and Canola
The country of England is known for - as the song 'Jerusalem' tells us - its green and pleasant land. Farmland makes up about 70% of the land area, and traditionally features neat squares and rectangles of crops, rather smaller than those in the great corn belt of America, and usually lined with long hedgerows of trees and shrubs. The fields - the squares and rectangles - are seen to best effect from a high vantage point, from the rolling hills of the Chilterns, or the Malverns, the Cotswolds or the Pennines. And traditionally the fields have been a patchwork of subtle shades of greens and browns and pale straw colours according to the crop which is being grown. Occasionally a field of the pale blue of linseed flax, or uncultivated fields speckled with the red of the wild field poppy, would break the pattern of the greens and browns.
But in recent decades, a new colour has been added to the mix. A very bright colour. Each year, usually early in April, one will see a few specks of yellow in some of the fields of the English countryside, and also along the roadside verges and in the hedgerows, where the yellow has self seeded and now grows naturally. Gradually the yellow in the fields brightens and deepens and extends to fill in the spaces, until whole fields of unbroken golden yellow are splashed across the countryside - a display of brilliant intensity.
This is oilseed rape, also known as rapeseed, or rape, a crop which has become a major feature of the English landscape in the two months of April and May, and indeed is now a familiar sight in so many countries across the globe. This page is a pictorial review of the crop, its history, its agricultural impact, and the contributions which it makes to the environment of the countryside.
- All photos were taken by the author in England. Some of the landscape images were taken in the county of Cambridgeshire a few years ago. These have all been labelled thus. The majority of photos were taken in the county of Essex within five miles of the author's home during the growing of the rape crop in 2012.
DERIVATION OF THE NAME
Rapeseed or oilseed rape is just one member of the Brassicaceae. This is a family of plants which has provided mankind with a significant and highly important range of crops, including cabbage and cauliflower (Brassica oleracea) and varieties of mustard (Brassica - various species). The family also includes turnip, the Latin name of which is Brassica rapa, and it is from the species name of turnip - 'rapa' - that the very closely related species Brassica napus receives its curious common name of rape, a name which was first employed in the 14th century and was later applied to all those plants from the family which were primarily grown for the extraction of vegetable oils (as opposed to those grown primarily for the consumption of roots or leaves .
HISTORY OF RAPESEED
The origins of rapeseed - B. napus - are uncertain, partly because of the close relationships and propensity for hybridisations between the different species of Brassica, but also because naming distinctions were not entirely clear until comparatively recent times. The wild form of B. napus has not been discovered, and it is possible that it is a natural hybrid between Brassica oleracea (cabbage) and B. rapa (turnip). Even in recent decades, selective breedings of new cultivars have involved hybridisations with several other species in addition to B. napus. But whatever the truth of its botanical history, geographically rapeseed would seem to be a plant originally from southern Europe .
Although some members of the family Brassicaceae were certainly grown in Bronze Age times and in ancient Rome, plants which can be described as oilseed rape are believed to have been first cultivated in West Europe from about the 13th century, whilst records from the 15th century are definite and many, and refer to the crop as a source of animal feeds, and of lamp oil for lighting . The time of the industrial revolution then greatly expanded the uses to which rapeseed was put, and in the 19th century, the oil was developed as a lubricant for steam engines , Later on it was also used in the manufacture of products such as soaps and plastics . World War Two also gave a boost to the cultivation of rapeseed crops in the USA, specifically as a lubricating oil. This was because the oil adheres well to metals under moist conditions - a quality which made rapeseed oil especially invaluable in naval applications .
This then was the state and range of the crop's uses to mankind in the middle of the 20th century.
THE LATE 20TH CENTURY - THE DEVELOPMENT OF CANOLA
Up until the middle of the 20th century as we have seen, traditional uses of the plant were predominantly in the fields of animal fodder production, fuel oil production, lubricating oil production, and a few other industrial applications. No mention has yet been made of its use in human consumption, and that may seem strange given that this is a crop in the family Brassicaceae - a noted food crop family. However, rape in its original form suffered from a well recognised drawback. Two of the component ingredients are erucic acid and glucosinolate. Erucic acid in high concentrations has been related to heart disease, and extracted oil contained 50% acid by volume. Glucosinolates give the oil a bitter taste, and break down to release mildly toxic byproducts causing digestive problems . Both characteristics made rapeseed products poor candidates for human consumption (and indeed even for animal fodder, though it had been used for this purpose). Aspects of this problem were known even back in the 16th century. Czech author Cernobyl (1587) lamented that the 'oil is also very good, if somebody knows how to remove bitterness from it' .
All this however was to change in the 1960s and 1970s, and the driving force for this change was in the province of Manitoba in Canada. Selective hybridisation of B napus and the related species B.juncea and B. campestris gradually reduced the erucic acid content and glucosinolate content to make new cultivars of the crop which were more palatable. These new cultivars were described as 'double low' or 'double 00' as both of these negative components were reduced as low as possible. (Double low indicates that the processed oil contains less than 2% (USA) or 5% (Europe) erucic acid and the rapemeal less than 3 mg/g of glucosinolates) . In 1979 the Western Canadian Oilseed Crushers Association gave the new, more palatable strains the name by which they may be known in North America. It was described as CANadian Oilseed Low Acid or 'CANOLA' . Today, the name of 'Canola', as distinct from 'rapeseed', is specifically applied to all edible rape crops rather than types grown for use in industrial fuel or lubricant production . Often indeed, 'Canola' and traditional 'rapeseed' are now identified as two quite different crops.
Rape is a crop of temperate regions, and is not suited to the tropics or to high latitudes . A degree of frost tenderness has limited eastward and northern spread in Europe. However, reduction of toxic components in Canola has not been the only aim of plant geneticists. They have also been aiming to make the crop more hardy, capable of germinating and growing at temperatures not much above 32ºF, 0ºC. This would enable the crop to be grown much more widely. Ideal sowing conditions are well drained soils with adequate water during the growing season, though the crop is quite tolerant of different soils and different salinities .
Two different seasonal plantings have been developed, though both flower in the spring. 'Winter' crops will be sown in the early Autumn to ensure sufficient growth before potentially severe weather conditions set in, and should be ready for harvesting in mid-summer, and these tend to produce a higher yield. The drawback of course, is that any frost tenderness limits the geographical range of such plantings. 'Spring' crops will be sown as soon as possible after frosts, for harvesting late summer, and this is the option in colder regions . After vegetative development, flowering takes several weeks, after which seed pods mature over a period of about 6 weeks .
Flowers are mostly self-pollinated, and this is desirable especially in the case of Canola cultivars. This is because although insect and wind pollination also contribute, these can lead to cross hybridisation between Canola and many closely related species of cultivated and wild Brassicas, raising the erucic acid and glycosinaolate content to unacceptable levels .
A SUMMARY OF THE MAJOR COMMERCIAL BENEFITS
One key reason for the successful spread of oilseed rape as a crop has been the sheer versatility of the plant. Since it was first grown in the Middle Ages, the number of uses to which it can be put has expanded hugely. The following is a list of just some of the commercial uses:
WINTER COVER: One of the benefits of winter rapeseed is the protection it gives to the soil, helping to prevent nitrogen and other nutrients being leached out during the very harshest months of the year .
ANIMAL FODDER: 40% of the seed yield is oil, and 23% is protein. The remainder of the seed is available in addition to the leaves and stems as 'rapemeal', a high protein animal feed historically used for pigs and poultry, but now primarily reserved for cattle. In Europe this is a major usage of the crop . The development of Canola greatly increased its value in this regard.
HONEY: Perhaps it is a minor by-product, but honey may also be obtained from the nectar of rapeseed. The taste is apparently strong, but combination with milder honeys makes it suitable for human use .
OIL FOR HUMAN CONSUMPTION: Of course the most obvious use to which a vegetable oil may be put is in human consumption and in cooking, and since the introduction of Canola or double 00 varieties, this has been the most significant boost for oilseed rape cultivation. Canola seed oil is not only palatable; it is also healthier, as it is lower in saturated fats and higher in polyunsaturated fatty acids than the original rapeseed, and it is therefore frequently an ingredient in cooking oils and margarines .
FOOD FOR HUMAN CONSUMPTION: Although rapeseed is traditionally an oil producing crop rather than an edible leaf and root crop, in the Far East, Canola is used as a spinach-like stir-fried vegetable .
FUEL OIL IN MODERN MACHINERY: Rapeseed oil is used in modern machinery, just as it was used in 19th century steam engines. The benefits are many, and although more expensive than mineral oils, it is claimed to be more environmentally friendly and less hazardous . In several countries, such as Austria, some mineral fuels - for example petroleum based chainsaw oil - have been banned because of environmental concerns, thus increasing the value of vegetable oil fuels . The past decade has even seen the introduction of a new term for such oils - biodiesel, a sustainable, growing source of fuel for diesel engines and many other industrial applications. Rape is by no means the only source of biodiesel, as the fuel can also be obtained from soybean oil, algae, and animal fats such as lard and fish oil, Indeed, soybean is by far the most important source in the USA, but the value of rape in this regard is increasing, and about two thirds of European rapeseed oil production now goes into biodiesel fuels .
GLOBAL EXPANSION OF PRODUCTION
As will probably have been appreciated at this stage in the article, rapeseed and Canola - if one chooses to differentiate between the two - are two crops which have undergone immense expansion of cultivation in the last 50 years. The proliferation of uses to which rapeseed / Canola have been put has increased the market price and led to much more land being given over to the crop .
World wide production in the 1950s amounted to a mere 3.5 million metric tons (3.5 million kilograms). By 1975 this had more than doubled to 8.5 million metric tons, and by 1985, it had doubled again. In 2006, global production had expanded to 47 million metric tons, and it is still rising . Oilseed rape is now the world's third largest source of vegetable oil after soybean and oil palm . It is also the second leading source of protein meal after soya .
This boom in production has come from two key developments and one ecological consideration, all of which have been alluded to above, and are here summarised:
- PALATABILITY OF CANOLA: The first development was the hybridisation and selective breeding of Canola, which has enabled a vegetable oil to become palatable and therefore harnessed for more than just lubrication and fuel. Canola has seen a massive rise in the commercial cultivation of rape for human and animal consumption. In Europe since 1991, virtually all rapeseed has been 'double low' .
- HARDINESS AND RESISTENCE TO DISEASE: In conjunction with the development of palatable Canola strains came development of hardier, more frost-resistant varieties, as well as the development of disease resistant strains, and these factors have enabled the expansion of the crop not merely in terms of its gross production figures, but also in terms of its increased geographical distribution to the colder regions of Europe and Canada.
- ECOLOGICAL CONSIDERATIONS: The rise in ecological concerns over sustainability of resources has also increased demand for the crop. Depletion of fossil fuels such as petroleum, natural gas and coal, have recently led to the development of biodiesel - vegetable oil (or animal fat-based) fuel for use in diesel engines, or as a low carbon alternative to heating oil. In the UK, fuel suppliers are now obliged to ensure at least 5% of all fuel is from renewable sources - ie, from biodiesel. Similarly use of biodiesel is increasing in the USA since the Energy Policy Act of 2005.
Since World War Two in the newly formed European Community, generous subsidies have encouraged farmers to grow the crop. 16 million metric tons are now cultivated annually, with Germany and France the leading producers. In Great Britain, oilseed rape is now the third most important crop after barley and wheat . In Western Europe, winter grown rapeseed is most common , In Eastern Europe, production has been hampered by the severe winters, but spring grown rapeseed, in conjunction with other spring Brassicas and the introduction of selected hardier varieties as indicated above, is increasing the geographical range .
India and China also became major growers post-war, and India now has 10-15% of its farmland under rapeseed cultivation, producing 6 million tons annually . China as an individual country is now the world's largest producer of oilseed rape in all its forms, responsible for more than 12 million metric tons in 2006.
The role of Canada in the development of Canola led to its pre-eminence in the cultivation of double 00 varieties with 9 million metric tons harvested annually, and today this - with wheat - is the leading crop in that country . The aim is to increase the total production figure to 14 million tons by 2015 . The seed and seedlings of the rape crop are naturally prone to many soil pathogens, and undoubtedly, one of the policy decisions which enabled Canada to assume this pre-eminent position was the authorisation to use seed protection fungicides, which were not sanctioned or registered in all other countries. Genetic modification has played a considerably greater role in Canada than in Europe, where most crops are free of modification . In Canada's main rape growing provinces, 82% of the crop is genetically modified spring rape .
In the USA, rapeseed is still a less significant crop but is now grown extensively particularly in the corn belt and in the southeastern states. Minnesota and North Dakota are the two biggest producers .
A SPLASH OF BEAUTY OR A GARISH SCAR? - EFFECTS ON THE LANDSCAPE AND OTHER CONTROVERSIES
Any monoculture crop will inevitably provoke controversy in the modern, very ecologically minded era, and especially so when it is a crop which has undergone many hybridisations and genetic modification, particularly in Canada. (The majority of European production is GM free) . For every proponent of this crop as a provider of increasingly healthy vegetable oil and a sustainable natural source of fuel, there will be a detractor who can point to concerns over extensive genetic manipulation, and environmental downsides which include the use of nitrogen fertilisers in the cultivation of Canola leading to the release of the greenhouse gas nitrogen dioxide . Some also suggest that ecological benefits of biodiesel fuel are not as impressive as they may seem at first glance. This article is not intended to open up the debate, but interested parties can read the articles listed in the references later, and other links from these.
In addition to the environmental and health issues, the crop also have its aesthetic detractors. Although in the caption to one of the photos on this page, I described oilseed rape as 'affording an attractive vista for those who have their homes nearby', some claim that these plants cause allergies and hay fever like symptoms, asthma attacks and conjunctivitis in some members of the population . It also has a pungent odour when the wind carries the scent, and it remains a matter of opinion whether the fields of gold are fields of beauty or fields of unnatural garishness.
Canola or double low rapeseed (as opposed to traditional rapeseed) is considered safe for human consumption in all nations, and advocates claim it is beneficial in the reduction of cholesterol levels. Further research is being undertaken to introduce ultra low saturated fat and Omega3 enhanced Canola for the health conscious age we live in . More efficient methods of oil extraction from the seeds are also under research with new technologies to reduce the price, and many new products which harness vegetable oils like this are being developed . Whatever controversies exist, it does seem that this yellow crop is here to stay.
Please feel free to quote limited text from this article, or to use my photos, on condition that a viable link back to this page is included
When all is said and done, I should say I am not an agriculturist nor am I an economist, and my ecological knowledge on this subject is limited to the information I have researched on the Internet. I would direct readers to the pages listed below, and to further links from these sites for more detailed information on all aspects of the development and cultivation of rape crops. My principal reason for writing this page was simply to record and illustrate with photographs the reasons behind the extraordinary change which now occurs every twelve months in the fields of England, and increasingly in so many other countries of the world, as brown gives way to green and then to vibrant brilliant yellow.
For good or bad, oilseed rape has certainly made its bold and extravagent mark on our countryside.
LINK TO ALL MY OTHER PAGES
- Greensleeves Hubs on HubPages
I have wriiten pages on many other subjects. These include travel guides, film reviews, articles on astronomy and linguistics, creative writing and more. All can be found at the above link