Monday, August 6, 2007
Monday, July 30, 2007
El Niño grows up?
Australia, country of immigrants, kangaroos and variable and extremes climates. The past year will stay on the books and in Australian people’s minds as one of the worst drought-hit in recent times; it destroyed entire crops, with a severe impact on the agriculture and the economy of the country. (Major crops such as wheat are down more then 50% on an average year)
Let’s have a look at a report dated 1791 from the Australian governor Arthur Phillip: “From June until the present time so little rain has fallen that most of the runs of water in different parts of the harbour have been dried up for several months…”
And again 1814 after another severe drought that forced the Australian government to import big quantities of food, another report stated that was necessary to avoid “…the heavy calamity of very great scarcity, both of animal feed and of grain, if not in actual famine…”
This year event has been not so unique for Australia; is possible to find similar situations in the most recent 1997, 1982, and more and more backwards in time.
As others drought and floods of the past, especially in certain world areas, we have several records. In 1877 famines in various parts of the world, determined by more then unusual meteorological patterns, caused the death of nine million man and women in China and a close amount in India.
Since this catastrophic year, started the first attempts to understand the phenomenon behind those dramatic weather events; in fact was empirically evident how Australia and India experienced droughts at the same time and the particular atmospheric pressure difference before the event occurred, but they were still far to have a scientific theory.
From time to time torrential rains and floods hit the normally arid north-western coasts of Peru; there are written records of the same kind of storms dated 1525, and researchers have found evidence of heavy floods during the Inca period going back in time more then 10.000 years ago.
Peru’s fishermen enjoy (along the usually cold and rich deep sea coasts), flourishing fish populations. They had noticed how around the Christmas period in certain periodic years (every three to seven) the ocean would heat up for few weeks, drastically diminishing the fish populations: they called this recurrent period El Niño for the Christ child.
Also if this anomalous and recurrent extreme weather conditions has been recorded hundreds years ago in different parts of the globe, just recently has been linked as part of a singular big phenomenon now known as El Niño.
In fact it was not until 25 years ago that the scientific world intensified his efforts to deeply understand how El Niño works globally.
I’ll try to make it as simple as possible without being involved in difficult (for me as well) technical theories.
The main energy that drives world climate is the sun. More of this energy is received in the equatorial regions than at the poles. This “imbalance” is redistributed by the oceans and the atmosphere, transporting the excess of energy from the equator to higher latitudes.
The earth rotations cause the air moving away from the equator to turn eastward; the cool air that returns from the high latitudes instead creates a westward movement.
These movements leads to the so called “trade winds”, that have effect again on the oceans; in fact the Pacific ocean is warmer in the west(and this causes heavy rains in this tropical areas such as Indonesia and New Guinea) then in the east( around the Indian Ocean and the west Pacific where is much drier).
During El Niño periods this situations reverse and the trade winds nearly disappear.
El Niño is caused by a sort of cyclic chain effect: a small change in temperature on the sea surface can produce a change of winds along the equator. This affects the currents which changes the sea surface temperature even more. And so on. After a certain period of time (not determinable), the usual air-pressure pattern reverses itself and is higher in Australia than they are in the central Pacific; this atmospheric variations is called ENSO (El Niño/Southern Oscillation).Often El Niño is followed by La Niña (also called El Viejo) that has diametrical opposite effects characterized by unusually cold ocean temperatures in the equatorial Pacific, flooding in Australia, India, Indonesia, Brazil, and dry conditions on the Pacific coast of South America; this changes associated with El Niño, last for around a year.
The clearest sign of the ENSO is the inverse relationship between the air pressure of two sites; Darwin in Australia and in Tahiti.
The main atmospheric consequences consist in a shifting of jet stream, storms and monsoons, causing severe weather changes (droughts and floods) over many regions of the world.
T he economic impact is relevant as well. Peru’s fishing industry is heavily hit (in favour
On the other side it can have some positive effects: it generally reduces tornados that usually strike the U.S. by half; on lands in Northern Peru, usually too dry for any cultivation, is possible to grow rice or beans. During 1997-98 El Niño, Northern USA States saved an estimated five billions dollars in heating costs.
The 1997 El Niño will be remembered for his strength: it carried more energy than a million atomic bombs; it killed an estimated 2100 people and caused damages for 33 billion dollars. Where there was a sand desert, created the second largest lake in Peru, 145 km long 30 km wide and 3 meters deep. Forest fires burned in Sumatra, Borneo, and Malaysia.
Kenya’s rainfall was 100 centimetres above normal, Madagascar experienced heavy monsoons and cyclones, violent floods stroked central Europe killing 55 in Poland and 60 in the Czech Republic.
El Niño is a natural event, an ordinary part of life on the planet of which there is evidence for many thousand years. But its consequences can be devastating.
Predicting this event is hard: researchers are using, together with the statistical approach, helped by ships, aircraft and buoys collecting data, computer models in the attempt to reproduce interactions between ocean and atmosphere.
Is not easy to understand how the global warming of the last century (which amounts to one twentieth of degree Celsius) influenced El Niño and La Niña. But the models indicate that the rainfall anomalies become stronger with the Greenhouse effects, and conditions could get more unpredictable with further climate change caused by humans.
Still researchers have to work hard to fully understand the mechanisms and cycle of El Niño and especially to find reliable methods to forecast its impact and evolution, for the great benefit in planning for drought, flood and to limit to the minimum extent the loss for property and human lives.
Sunday, July 29, 2007
A) Origins and brief history
Wheat is the most widely cultivated cereal grain in the world; it occupies around the 17%(220 million hectares) of the total cultivated land in the world, and is grown in the widest wide range of climates and soils; however wheat gives his best results in temperate regions.
It is the main staple food for the 35% of the world’s population, supplying about 20% of the world’s calories, and has been feeding entire generations. Among developing countries, wheat is planted on about 100 million hectares.
The wheats known today evolved from a type of wild grass native of Asia Minor in an area comprising Syria, the old Mesopotamia and Turkey.
It is thought, according to DNA evidences that the first cultivation of this grain began 12000 to 10000 years ago, after the repeated hybridisations of the Triticum grass family; modern varieties are due to the selection of characteristics from their ancestral relatives such as:
Emmer: closely related to the modern durum wheat, dated around 7000 B.C., of which traces were found in the Pyramids and that was probably the main staple during the prehistoric era.
Einkorn: cultivated extensively during the Neolithic and Iron Age, in Europe. This variety is more resistant to cold, heat, diseases, although yields are not very high compared to others.
Spelt: similar to Emmer but with a tough husk that can’t be removed. Its use started during the Bronze Age.
Repeated cycles of harvesting and reseeding of those pre-wheat cereals, would have selected automatically the mutations in centuries. The importance of this cereal has been pointed out by several religions through the world, that join the origin of the precious grain with direct creation of Gods: the Egyptian imputed its appearing to Isis, the Phoenician to Dagon, the Hindu to Brama, the Arabian to Santo Miguel and the Christians directly to God.
Domesticated wild einkorn became extremely important in the diet of the populations of the Middle East where a family could, with a harvesting period three weeks, survive for a whole year.
Wheat was the ideal crop for Egypt since 4000 B.C. because its production cycle corresponded perfectly with the annual flooding of the Nile River and the efforts of only a part of Egyptians could provide food for all the population.
A wheat seed was the smallest unit of weight, a standard that was very uniform and accurate for that period.
Wheat cultivations fast spread through Europe (there was in the same period a parallel development through the Asian continent): as early as 6700 B.C., Swiss lake dwellers used wheat in flat cakes; Bronze age Greeks could have begun baking high-quality bread as early as 3300B.C.Wheat played such a dominant role in the roman Empire that, at the time, it often was referred to as “Wheat Empire”.
From the Middle Ages to modern times, this cereal becomes the predominant crop on which millions people depended: bad harvest resulted in famines and death for hundreds of thousands, both in country sides and towns. Wheat was also a primary trade good: abundance in the granaries represented power and richness for a Nation.
Wheat was one of the first crop seeds brought to the New World by European immigrants: it was one of the first cultures tried by the Portuguese in Brazil in 1534 at Saint Vincent, before the other Northern and South American colonists, with some success before rust appeared.
In the United States in 1602 on an island off today’s Massachusetts coast, the new crop was planted. But it was more a “hobby” plant then an important agricultural product before the late 1800’s; in fact European varieties hadn’t done well in the New World.
In the 1870’s Mennonites (mostly German peasants ) that left Russia for the U.S. and Canada to escape persecution, settled in Nebraska, Kansas, the Dakotas and central Canada and brought with them Turkey red wheat seeds and the know-how to cultivate.
In Australia settlers brought seeds of this grain in the First fleet in 1788.
Australia’s first wheat was grown at the Botanic Gardens in Sidney, and then successfully cultivated during the 19th century in all the Australian colonies.
Wheat may be classed under main divisions (hard-soft, red-white, winter-spring), several subdivisions and species.
The cultivation cycle of the wheat plant varies depending upon the variety being grown.
In the northern hemisphere Winter wheat is planted in September or early October, and the germinated seed lies dormant during the winter. It requires a period of below-zero before the plant resumes its growth in spring (process known as vernalization): after the head with his immature kernels emerges, flowering occurs and the kernels begin to develop until they are full and filled and start to dry quickly.
This quality’s wheat harvest begins in May and usually is completed in August.
Spring wheat is planted during spring when the temperatures are sufficiently high: it has the same growing features then the winter variety, but its harvest starts in late July and is completed in late August.
Three are the species commonly grown.
1) Triticum aestivum: forms the classes HRW (Hard Red Winter), HRS (Hard Soft Spring), SRW (Soft Red Winter), HW (Hard White), SW (Soft White).
2) Triticum compactum that includes club wheats (a low protein soft white wheat).
3) Triticum Durum includes the durum and red durum classes.
The terms “hard” and “soft” are related to the hardness of the kernel; red and white relates to the presence of a red pigment that colours the kernels in the outer layers.
Durum Wheat is so called because produces grains much harder then common hard wheats.
Hard wheat contains more protein (11 to 18 per cent) than soft wheat (ranging from 8 to 11 per cent); it also contains more gluten then the soft variety.
Each variety is genetically different from the other: these differences in characteristics range from physical attributes and qualities, to yields, resistance to drought or diseases.
Desirable varieties are obtained primarily by breeding; plants containing desired characteristics are crossed, and grown through generations and in the end adopted. However the introduction of the new biotechnology and genetic engineering has greatly shortened the time needed to create new qualities avoiding at the same time unwanted characteristics.
Due to the number of types, wheat needs standards categories. In the US there are eight classes, each divided into five grades, depending on the purity of the wheat and overall quality. In Argentina there are two major wheat types and four grades. Australia has seven wheat types and three grades, while Canada has seven classes and nineteen grades.
The most important wheat part is the kernel: this is divided in three major components.
The bran is the outer layer that protects the whole seed; it includes roughly the 15% of the kernel in weight, and has a high content of minerals and fibres.
The inner part of the seed is the germ that comprises just the 3% of the kernel; however it contains most of the lipids and essential nutrients.
The remaining part is the storage endosperm characterized by high protein and starch content: the endosperm is the main part of the kernel and is the primary component of flour.
Any problem with the plant during its growth cycle can affect characteristics of wheat flour: for example wet conditions during the harvest can cause sprouting (the mature seeds germinate in the field) sometimes negatively affecting the quality of the flour.
To keep into account by farmers is the reverse relation between yields and the protein content of the seeds.
Wheat is subject to more diseases then other grains; among major enemies are molds that in some cases may produce toxins such as vomitoxin: in this case the consequences are severe because the crop will not be suitable for any purposes, including animal feeding.
Farmers also face insect pests and weeds that can contaminate the kernels or diminish the quality of seeds.
Common and alternative uses
The most important use of wheat since early times has been for food use. Bread was the staple food of humanity for many centuries, together with rice.
Today is still such an important food that we can find on the tables of any social class and culture.
Over time the use of wheat has been highly diversified to create different wheat flour products; usually hard wheats are used in the production of breads and others yeast leavened or dough- based products: the ability of this kind of flour, to retain gasses gives bread the traditional texture and structure.
Soft wheats are mostly used for cakes, crackers, cookies and other products that don’t need to be so “elastic”, but, instead tender, flaky or crispy.
Durum wheat with its properties of protein content, and the yellow colour of semolina, is mainly used for pasta and noodles products.
Roughly two thirds of wheat produced in the world is used for human consumption, while around one sixth is used for livestock and poultry.
In most cases low quality wheat, parts of the plant unsuitable as human’s food or by-products of the flour milling industry is used for feed.
The properties that make wheat suitable in food products, gluten (protein) and starch make it a good source of raw material for non-food and industrial applications, where the potentials are huge.
There are also uses for the by-products: straw (composed mainly of cellulose) and bran.
In particular straw transformed in the form of wood sheets (strawboard) is used in “ready to assemble” furniture, flooring, lamination of cabinets and other wood substitutes; these boards are of acceptable quality for interior applications, but not for exterior locations due to the poor durability and lack of resistance to weather.
Bran applications includes stabilisers in paints and other uses in cosmetics; its high value is particularly associated to form mechanically and chemically stable gels to be used as medical delivery systems.
Starch is widely used in industrial and others applications.
In fact wheat starch makes paper stronger; it is used as an adhesive (for example on postage stamps) or for plastic bags and films, packaging, eating utensils, building materials.
In the food industry starch can replace fats in desserts, as milk and cream substitute, and in other non dairy products.
It can be used in the cosmetics and pharmaceutical industry in hair conditioners, moisturizers, detergents.
D) Wheat in the developing countries
In the developing countries wheat is one of the major food resources, providing more calories and protein than any other crop.
Wheat is planted on more then 100 million hectares in the developing world, where two qualities predominate: 1) Bread wheat compose the biggest part of the wheat sown in Central and South Asia, eastern and southern Africa, and parts of South and Central America.
Forty percent of this crop is produced in irrigated environments. Major producers in this special list are China followed by India and Turkey : in the first two countries often wheat is produced in the irrigated rice-wheat rotation.
2) About half of all the Durum wheat production in the world is in the developing countries, especially concentrated in the Middle East, Central India, and the Mediterranean region.
However, in these countries, production of Durum is low because of the difficult climatic and soil situations, low levels of inputs used, such as water and fertilizers, that affect the crop output. Production is for all this reasons fluctuant and yields extremely different between countries.
For all wheat, yields in the developing countries is now around 2.5 tons per hectar, but can be as low as 1 tons per hectar in marginal fields, where local wheats, not resistant to diseases or
others kinds of stress, are mainly used.
In the last 20 years yields has grown consistently because of the expanded use of irrigation, pesticides, and fertilizers; the introduction of new varieties that use nutrients efficiently and tolerate drought and diseases in a better way, was another important reason. Comparing to the developed countries, yields grew in the developing countries with a fast pace reaching a similar level of the the richest one in the mid 90’s.
Most of this increase is due to the excellent growth rate of China (around 2.6 percent per year during 1982-1991), India and Pakistan (with increases of nearly 3%): these three countries produce the biggest slice of total developing nations (around three quarters of total). The main use for this higher availability has been for food use, while the increase for feed or other uses has been only marginal. I
Main problems for wheat farmers in the developing areas come from both abiotic and biotic stress.
Wheat plant can suffer from different kind of abiotic (non-living) stress, such as drought, heat, waterlogging, and from soils with low or too high PH or mineral deficiencies.
Around one third of the crops of developing countries suffers during the growing season some type of drought stress caused by low rainfalls (<500>
Depending from the growing period when drought occurs, yields can drop drastically.
Heat stress may contribute to heavy losses: in fact especially in the sub-tropics countries, daily temperatures are often higher then 18°C during the cold season, too high for the winter wheats mainly used in those countries.
The best insurance against this kind of risks, are given by varieties genetically resistant to heat and drought that can give better yields also during the harshest periods.
An excess of water can be also the cause for a poor crop: this situation, called waterlogging, can be usually occur in the rotation system rice-wheat used in South Asia.
Breeding is the best way to develop water-tolerant wheats, and new breeds from wild relatives of wheat are giving good results.
Other growth-limiting factors are due to the characteristics and minerals present or not in the soil.
In some areas such as in Brazil , other South American regions or Central Africa, soil has a acidity that is too high to grow a good wheat crop; this is often due to the presence of aluminium that is toxic for the plant. In the South of Australia, China, South Asia, Philippines and part of South America the presence of Boron is another cause of toxicity.
In other areas, such as Turkey, Afghanistan, Egypt, Iran, Iraq, Southern Australia and others calcareous territories of arid and semiarid regions, zinc deficiency reduces grain yield and the nutritional qualities of the grain.
Between the biotic stresses, wheat fears diseases such as stem, leaf, yellow rust, Karnal bunt and many others that can be defeated both through chemicals applied to the crop or developing plants genetically resistant to these diseases.
Weeds is another main concern for farmers, especially the very common Phalasis minor that can cause serious problems to the destruction of an entire crop. Weeds are commonly fought with chemicals.
Insects could as well cause losses. Among the most dangerous are the Hessian fly, sunni pest, and sawfly that occurs periodically in Central Asia or Northern Africa where varieties resistant to these pests have been introduced.
Oat is an annual plant that belongs to the family of Graminaceae,and of which around 25 varieties are known that grow worldwide in all temperate countries. Cultivated oats can be planted either in autumn for an early summer harvest, or in spring for a late summer harvest.
This cereal is a relatively newcomer. In fact the history of oats is short compared to other grains.
Its origins are in the Middle East dating back to around 2000 B.C. : common oat is derived from wild species that were cultivated by the Germans and the Celts in the Bronze Age and used extensively by the Roman Empire.
Early use of Oats was probably for medicinal purposes; oats flour is quoted in the book “About Medicine” by Aulo Cornelio Celsio author of this fundamental medical work of the roman period.
Plinio, Columella, Teofrasto , and other roman writers described oats as a useful medicinal substance, especially in dermatological pathologies.
But there are references to oats as a cultivated crop just starting from the beginning of the Christian era. And the cultivation of this cereal was extensive in Europe prior to the discovery of the New World where pioneers carried the first seeds.
The fortunes of this grain derived from his capacity to adapt to conditions where wheat and barley won’t grow such as mountainous areas or where the climate is too cold and humid for others cereals, thus allowing the local populations to make the most of lands otherwise unproductive especially during harsh periods.
Also nowadays one of the biggest producer and exporter is Finland, situated at the same latitude as Greenland, where it is cultivated as high up as in the southern parts of Lapland.
The success of oats depended too on the large number of horses that were used for work in the countryside and for armies , and that were the main mode of transport for several centuries.
In fact the principal use of oats has always been for animal fodder (especially horses).
However things changed radically during the last century and this grain has rapidly lost its importance. The cause of the loss of interest is due to the better yields, facility of cultivations and economical returns from others cereals, such as wheat, maize or barley. The demand for oat as feed grain weakened progressively after the innovation in modern times of the internal combustion engine,and the consequent reduction in the use of horses.
Furthermore, consumer interest shifted to other cereals products that were easier to process and met the tastes of the market.
World production dropped sharply in the last 20 years following the “oat fibre boom” in North America. In 1980 41 millions tonnes were produced worldwide, representing 6% of all coarse grains. In 2001 production was around 27 millions tonnes just 3% of total coarse grains. The drop is due to spreading reduction of harvested area, particularly among producers such as Usa, where farmers have been free to plant crops that provided the highest market return.
All this despite the innumerable uses and the potentials of this multi-purpose cereal.
In fact, oats have so many properties that could boost its consumption again (presently just 5% of production is used for human food consumption).
Oats are the most nutritious of the cereal grasses containing over four times as much fatty acids and 19% more calories then wheat, with the 80% of this fats being unsaturated
The fruit contains alkaloids, such as granine, avenine, saponins,and flavonoids powerful antioxidant. Seeds are rich in iron manganese and zinc.It is a good source of vitamins B1, B2, D, E and an excellent source of carbohydrates and fibers.
Together with the unique nutritional properties, oats has been recognized to be : antidepressant, antispasmodic, demulcent, emollient, a good remedy for nervous exhaustion, insomnia, helpful in prostate disorders, and a tonic; they are believed to lower LDL cholesterol and thus possibly reduce the risk of heart disease.
Oats are considered a “cleansing grain” for their beneficial effects on the intestinal tract and as a blood purifier. The complex of carbohydrates that it contains have been linked to the reduction in the risk of cancer, and for the control of diabetes.
Human’s do not usually consume oats before they have been processed: like barley, it is a difficult grain to separate from the hull. Grains have to be cleaned, and toasted, before being used as a ingredient in a wide variety of food products such as breakfast cereals, snacks, crackers, cookies, beverages.
Oatmeal is also an excellent soup’s thickener and a filler in meat loofs and casseroles; mixed with wheat flour it forms the basis for multigrain baked products.
The Scots and Irish made a cuisine out of oats: Samuel’s Johnson considered in his famous work of 1755, oats as ”a grain food for horses in England, but for men in Scotland ”to which the Scots’ reply was “Aye, and where do you find better horses or finer men?”
The most valued and major component of oats is the bran from which it is possible to extract an edible oil as well, that is very high quality but too costly for commercial application.
The list of uses of this flexible grain goes on: oat straw is used in corn dolly making, and is the favourite filling for lace-making pillows; the extract of Avena Sativa (Latin name for Common Oat) is said to free up bound testosterone in both men and women. Recently an oat milk has been developed that can be used as a base for making different milk free dairy products, such as yoghurt or ice creams; it apparently help with withdrawal symptoms from tobacco addiction, and is used in the cosmetic industry as talc replacers and in skin care products.
What will the future be for such a virtuous cereal?
In Nepal, and other areas of the Himalayas, green feed oats have helped significantly to improve nutritional standards; the breed of new adaptable species could improve food resource to alleviate starvation in certain regions of the world in the future.
Awareness among consumers in developed western countries of organic and not genetically modified products, is increasing rapidly as well as the demand for such products.
Oat-derived products represent one of the best examples of functional foods that, along with their nutritional capacities, have been shown to improve health or prevent illness. If governments and private companies, will promote and support the production, research ,and marketing, to full rediscover the potential of Oats, this cereal will have back the space that probably deserves.