Cereals

The plants called cereals are types of grass on which grow the seeds that feed most people on earth.

Flour, bread, toast, crumpets, porridge, oatcakes, crackers, corn flakes, rice crispies, semolina, bannocks, all come from the cereals. So do beer, lager, rum and whisky. So do rice, pasta, sweetcorn, tortillas, couscous and pizza-bases. Haggis, muesli, gin all have some cereals in them. Cows and pigs are fed on cereals. Some paper, cardboard and plastic containers is made of cereals.

The cereals, with the legumes (beans and peas), together are our staple food. They have been grown since agriculture began here. A feast of beans on toast, topped by semolina pudding, celebrates 5000 years of  cereals and legumes.

The cereals panel shows, left top to bottom: emmer wheat panicle and grain; black oat grain; beer made from barley and wheat by a micro-brewery in Scotland; loaf made from bread wheat. And right, top to bottom: types of pasta made from durum wheat and noodles from from rice; barley and wheat growing together in a field - the barley as a weed; spelt wheat  panicle, grain and cracker; sorghum grain on the panicle. Panicle is the name given to the flowering and fruiting 'head' or 'ear' carrying the grain. All photographs Living Field collection.

 

 

 Main points

  • cereals crops - of which the main are maize, rice, wheat and barley - were domesticated about 10,000 years ago in different parts of the world
  • migrants and settlers brought cereals to these islands at various times over the last 5000 years
  • barley, emmer wheat and bread wheat were the earliest cereals brought here -    over thousands of years, farmers and stock-raisers have built a stable provisioning ecosystem on these cereals
  • the main cereal species grown here have changed over time - about 150 years ago, oat was the main one, followed by barley; by 1950, barley was dominant; now barley is still the most widely grown, but bread wheat has increased
  • the climate and soil of the maritime croplands yield heavy crops of modern cereal varieties - yield increased steadily over the last 100 years but has now levelled, for reasons uncertain 
  • the high yields have not come without environmental cost - modern, intense cereal production is causing loss of biodiversity and ecological function in the croplands
  • apart from things made from oats, most of the cereal food eaten by people in northern Britain - bread, flour, pasta, rice - is imported
  • much of the present cereal harvest goes to make alcoholic drinks, mainly whisky and lager, or animal feed (though diversification is happening)
  • a sustainable future for the croplands depends on reversing the ecological declines due to past cereal production, reducing the environmental footprint of cereal growing, continuing to produce global brands and diversifying into new, high-value or nutritious products.

 

Cereals in the maritime croplands - the past

The cereals - of which the most widely grown in the world are maize, rice, wheat and barley - are all members of that most successful plant family, the grasses or Poaceae. The cultivated cereals have become different from most wild grasses in having the ability to bulk carbon compounds in their seeds (grain). They have large, carbohydrate-rich grains compared to their wild relatives.

All the main cereals were brought into cultivation at a time in prehistory, 10,000 years ago or earlier, when much of Britain was still covered in ice. Those cereals that could stand the cold and wet were brought here, first by late stone age or neolithic migrants, and then by bronze and iron age people, by invaders from Rome and Normandy and later by monks and multinationals.This import of cereal seed will continue into the future. None of the cereals that grow or have been grown in Britain originated here.

The species

Most of the cereals that have grown or now grow in the maritime croplands are easy to tell apart by their flowering structures called panicles, heads or ears. Not so if all you have to go on is partly burned grains (carbonised) buried in a pit for a few thousand years and then unearthed at archeological sites. Given the uncertainties in survival of seed and then identification, the absence of a species does not mean it was not grown here and the occasional presence of one does not mean it was grown widely, since it could have been brought here through trade.

Barley Hordeum vulgare has been grown from the neolithic (stone age) to the present. It is used to feed animals and to make whisky and beer, types of bread, bannocks, biscuits, pearl barley for stews and barley water. The species has potentially six rows of grain around the stalk of its ear but four- and two-row types are possible. The archaeological records show mostly a six-row barley. Remnants of these ancient cereals may persist today in the bere barley landraces that are grown in the far north and west, but given the likelihood of imports by trade, migration and occupation, continuity would be very hard to establish. (Landraces are crops that are maintained usually by farm-saved seed and become adapted to a locality.)

Emmer wheat Triticum dicoccum was one of the first cereals to be domesticated. Along with barley and with other wheats, it came from the early farming areas of the eastern mediterranean and west Asia. It was grown in Britain, but not any longer, even though it can be grown here, as shown right. There has been very little breeding of emmer, so the available types have long stems that tend to fall over. Their seeding heads, with a distinct alternating arangement and long awns, are unlike any modern cereal grown here.

Bread wheat Triticum aestivum is, like emmer, one of the first domesticated cereals and has come to dominate cereal lands in a great belt across the north temperate regions. It is less hardy than barley or oat, so tends to be restricted to soils and localities that allow its grain to ripen and mature. Like barley, it has many uses - bread flour and alcohol being the most widespread.  Wheat has been given a lot of attention by genetics and plant breeding, for example to reduce the size of the stem and increase the sink for carbon in the grain. In developed agriculture, the yields of wheat increased by around 1% a year for much of the last century.

Spelt wheat Triticum spelta was grown in Britain much later than the other two wheats, probably little before 2000-2500 years ago according to the archaeological records. Like emmer, it forms an attractive flowing canopy, but has shorter awns. It is still grown in eastern Europe, but not as a major crop because its long stems encourage it to fall over and spoil. Bread from spelt flour has a strong 'nutty' taste, from white-sliced.

Oat Avena sativa was first found a little before two thousand years ago. Its hardiness to cold and wet and the wide range of products that can be made from it, encouraged its spread and uptake, such that by the mid-1800s, it dominated the cereal land, being 70% of the combined oat-barley-wheat acreage by some accounts. It has been and still is an important home-grown food for humans and animals. 

Black oat or bristle oat Avena strigosa is difficult to distinguish from A. sativa in the prehistoric records. It has been grown widely until recent times as animal feed and has been eaten by people in times of famine. You get the impression that few people would want to eat black oat but many had to, during  lean years. Black oat is still occasionally present in Scotland, as a rare crop, perhaps for horse feed, and as a relic of cultivation when it becomes a volunteer or feral. It is taller than modern oat varieties, has distinctive black grains when the plant is near mature and grain that is more long than wide than grain of other cereals grown today. The seeding panicle, in its prime, has a delicate strength, similar to wild oat but fuller. 

Among other cereals, rye Secale cereale has been grown in the north of Britain, but is now very rare, confined to some areas of the west. Maize Zea mays and durum wheat Triticum durum have been trialled occasionally over the past few hundred of years, as have a few other sub-tropical cereals, but all were found wanting due to the season being too short for the grain to ripen. Maize has increased during the past century as a fodder crop but is still uncommon in the north.

 

 

Photographs above show sustenance made from modern cereals - pie pastry and white bread both from wheat flour and beer made from barley and wheat at a micro-brewery in Scotland.
 

The present

In most parts of rural, lowland Scotland, cereal crops occupy about half the croplands. The other fields contain grass, oilseeds, potato, vegetables, fruit, fallow and farm woodland. In the last century, particularly after the 1950s, important changes occurred in the way cereal crops are managed, and in that cereal farming could to a large degree detach itself from stock raising. By using high additions of mineral fertiliser and varieties that had less stem and more grain, cereal growing could do away with nitrogen-fixing legume crops and the need for animal manure from stock raised on the same farm. These changes have had great consequences for the economy and the ecology of the croplands, making them yield more but leaving them exposed to variation in global fertiliser costs that are tied to oil.

Despite the passing of time, farmers from the neolithic onwards would immediately recognise the cereal crops grown now, but they would see they were shorter in stature and heavier in the grain compared to the ones they knew.

The species

Three of the main species - barley, wheat and oat - are still grown widely and make up most of the cereal acreage. Of the cereals almost 70 percent (%) or seven tenths is barley, about 25% wheat and 5% oats, while small areas exist of others such as triticale. These proportions are not constant: as recently as the 1980s, the area sown with barley was even greater than it is now. Since then, the total area sown with cereals each year has hardly changed, but the area of winter wheat has grown relative to barley in some regions. In all these cereals, grain is harvested and the stem and leaf cut and bundled for animal feed.

Barley is the common cereal of east Scotland, the one with the very long awns that rise out of the tips of the sheaths enclosing the seed. Most barley grown here today has two rows of seed, one on either side of the ear.  Bere landraces, typically having 4 rows on the ear, are still grown in the far north and west, but will have other row-types among them. About five times more of the barley land is sown with spring varieties, sown in late March or early April, than with winter varieties sown in autumn. Barley is the most versatile cereal currently grown - it finds a place as the main crops on spring cereal farms, in mixed winter and spring rotations and in cereals alternating with grass ley. The main outlets for grain are whisky distilling and animal food. Some stock farms, especially in the north, grow barley solely to feed the animals.

Wheat Triticum aestivum is much stubbier in the ear than barley. Rub a dried wheat ear between the fingers and the naked grains fall out. (In barley the grains are encased in a tough sheath or hull.) Though known worldwide as 'bread'  wheat, little of the harvest here goes to make bread. Most of it goes to make alcoholic drinks such as lager. The protein content of the wheat grain largely determines what it's use for: the protein content varies with the variety, the nutrient management of the field and the weather. The wheat tends to grown on 'heavier', moister land, mainly but not exclusively in the south of the region. With a few exceptions, the flour that makes the bread you eat is made from wheat grown somewhere else, either in the south of Britain or overseas.

Oat is still grown for a wide variety of food products - oatmeal, rolled oats and flour of various grades, and cooked produce such as oatcakes. Its fortunes as a crop have changed over the millenia: after its arrived here 2000-3000 BP, much later than the other main cereals, it grew to prominence and was the main cereal a few hundred years ago.  It is now the  least of the main three, yet one which brings a degree of diversity to arable fields, and contributes healthy, home-grown food products having brands known throughout the world.

Of the other cereals - triticale (a hybrid of rye and wheat) and maize are grown on a small area both usually as animal fodder. Spelt and emmer are absent as commercial crops. Black oat has been grown within the last century, an there may be some fields still, but is found now as a relic of cultivation. Rye Secale cereale is hardly grown.

Yield and inputs

The maritime croplands of northern Britain are on the divide between good arable and good grass agriculture. Go farther north and west and the safest crop is the vegetative one - grass. To the east and south, the most economical is the reproductive one - the cereal, which has enough time and warmth to mature its grain. The maritime croplands produce high yields of the cereals, on average as high or higher than those in other regions of Britain. The yield is high because the cool weather extends the duration of the plants' developmental phases, allowing them to capture and convert more incoming solar radiation to foliage and grain than they do in warmer parts of Britain. The main risks to a successful crop are both damage over the winter and a wet summer and autumn preventing ripening and harvest. Some farms are all arable and others a mix of arable and grass. The proportions are likely to vary with shifts in climate.

The main differences in yield and agronomic inputs are not between the species of cereal - barley, wheat, oat - but between spring- and autumn-sown varieties. Spring cereals are sown in late March or April and harvested in August or September. Winter cereals are sown in the autumn and harvested the following July or August. The average grain yield of winter wheat in 2010 was 8.2 t/ha (tonnes per hectare) and of spring barley 5.5 t/ha. In most years, spring varieties produce 60-70% of the yield of winter varieties, but need a similar percentage of the inputs of fertiliser.

Imports

The cereal acreage, which now occupies about half of the arable land in any year in the maritime croplands, is not used to provide food for the local people. Most of it provides a substrate for various alcoholic drinks, such as whisky and beer, and animal food. With the exception of oat, most of the cereal flour and grain used to feed people here is imported as -

  • grain, flour and baked bread from bread wheat,
  • rice - the different forms of grain such as basmati, risotto, short-grain, and products such as rice-cake and noodles, 
  • the products of durum wheat, mainly pasta, including spagetti, lasagne and canneloni, and also semolina;
  • an increasing range of products from maize, such as polenta, breakfast cereals, tortilla and 'crisps'.

Therefore, except for potato and its products, and the nutritious oat, most of the traditional carbohydrate accompaniments to food, and almost everything in the food line that is Chinese, India, Italian or Thai, uses cereals grown well outside our maritime croplands. A range of other, less common, imported cereals are also increasingly available - for example, bread made from rye, crackers from spelt, and flour and seed from sorghum. Much of the seed that is imported to feed birds and other pets such as gerbils comes from the tropical cereals such as pearl millet Pennisetum typhoides and finger millet Eleusine coracana.

Contribution to the ecology

Because they occupy so much of the croplands, the cereals have a big effect on the stores and flows of energy and matter (the carbon cycle, the nitrogen cycle, etc.) and on the biodiversity and food webs of arable land.  And because they tend to be managed in a similar way throughout the croplands, any changes to their management will quickly permeate the region. Rehabilitation of damaged croplands will most readily come about by changing the way cereals are managed.

  • Spring cereals capture 60-70 percent of the sunlight captured by winter cereals and produce about the same percentage of biomass. The spring cereals need less fossil energy inputs, mainly through needing less fertiliser, again about 60%. (The highest users of fertiliser and other forms of fossil energy, and so the greatest contributors to greenhouse gas emissions are the winter cereals and also winter oilseed rape and potato.) 
  • On the other hand, because winter cereals take in more carbon from the air by photosynthesis, they deposit more carbon in the soil, thereby increasing soil organic matter. Trade-offs of this type - more fossil fuel used but more carbon deposited in the soil - need to be understood and actively managed.
  • The main contribution of cereal crops to maintaining life-systems is the mass of carbon compounds that they excrete to the soil when alive (called root exudates) and the materials they deposit through roots, leaf and stem matter and fallen grain when they die. This carbon is broken down by small invertebrate animals like nematodes, earthworms and springtails and by microorganisms like fungi and bacteria. The process of breakdown fuels the nitrogen cycle and creates and repairs soil.
  • Cereal fields in commercial agriculture offer little direct support to the plants and above-ground invertebrates, except for any spilled grain which adds to the soil carbon and feeds some birds and mammals. Why so? One reason is that the cereal plants themselves do not provide the variety of food and shelter needed by many insects and spiders. Another reason is they tend to be sprayed with herbicides that effectively remove the broad-leaf or dicotyledonous plants (weeds) that bring botanical diversity and habitat for small animals. Most wild arable plants - ounce for ounce or gram for gram - are much more diverse in structure and composition and will harbour ten times more invertebrate species (e.g. insects, spiders) than the cereals will. Many cereal fields are cleansed of wild plants well beyond the level necessary to achieve a high yield.
  • The cereal fields have also become more uniform in structure, each plant becoming similar to its neighbours in spread and height (unlike the emmer wheat shown right). Flowering and ripening occur at a similar time throughout the crop. Such movement towards uniformity is the result of both plant breeding and field management acting together so as to produce a crop that does not fall over when wet and can be harvested efficiently.
  • The uniformity of crop structure and the efficacy of herbicides have together reduced most of the non-weedy arable plants and made some of them so rare that they are on the most threatened lists of higher plants. Knock-on effects are that many invertebrates that feed on or shelter in broadleaf plants are themselves becoming rare.

[Back to top]

 

Prospects

Cereal production in Scotland supports major global brands such as malt whisky, but a large part of it still forms a general feedstock for lager and beer, and most of the cereal staple foods are imported. 

The species - any new ones?

Barley, wheat and oat have served the maritime croplands well for thousands of years, but this does not mean they will always be here. Barley and oat are hardy and adaptable and, provided the markets for their products remain diverse, it would take a cataclysm to remove them. 

For centuries, seedsmen have tried sub-tropical and tropical cereals and generally found they could not grow well enough. Shifts in climate might change the range and suitability of certain species, so provided seedsmen and farmers continue to experiment, the range of cereals may well increase. Maize, for example, might move further north if varieties are bred more able to mature in the cold and wet.

Yield, inputs, imports and exports

The cause of the yield 'ceiling' that appears to have been reached in the past ten years is not certain. Inputs such as nitrogen fertiliser have decreased in this period (a major plus for the environment), but many other factors, such as degradation of soil due to intense cropping, could have contributed. There are certainly no indications that yield is about to 'collapse', but there are no obvious ways to maintain or increase yield in the face of the large reductions of inputs, such as fertiliser, fuel and pesticides, that may be imposed in law and that in any case are needed to safeguard the wider environment. To move from where we are now in cereals is a major challenge for science and farming.

If the people of the croplands and their associated cities and towns continue to eat wheat bread, pasta and rice, then most of the carbohydrate in the diet will continue to be imported, much of it from outside the UK. The export of high quality cereal products such as malt whisky and the import of most cereal based food are sustainable in principle provided the respective markets and sources of remain in place.

Cereals in Scotland would benefit from a diversification of products, especially of high value manufactures, rather than of bulk production for heating or fuel. There are indications that diversification is happening. The recent expansion of micro-breweries producing specialists drinks, usually from home-grown barley and wheat, are an example of how a market can open.  Craft-based products of oat, bere barley and other cereals also appear to be increasing. More generally, specialist products such as 'plastics' for packaging are gaining ground. Modern genetics and biotechnology can assist diversification by producing new types of crop, for example, that are enhanced nutritionally, or serve new high value, low volume industrial markets.

Multi-functional cereal rotations

Yield and profit has never been the only function or purpose of cropland, but in the second half of the 1900s they certainly dominated the thinking in mainstream agriculture in Britain. Damaged soils and food webs can in principle be repaired, provided they have not been too far eroded, and recent research indicates that most of the croplands have not reached that tipping point. Moreover, much public opinion and government policy wishes the croplands to also support an attractive (and ancient) landscape, wildlife appropriate for the area, rural livelihoods and a choice of product and farming method for consumer and producer. Multi-functional croplands are possible but need to be managed as such: they can't simply be manged for short-term gain.

Cereal farming will also have to adapt to declining availability of inputs. Nitrogen fertiliser is getting more expensive and there are already curbs on when and how much of it can be used.  Phosphorus fertiliser will run out sometime in the next 100 years. Many chemical pesticides can no longer be used because they are considered harmful.

Nevertheless, the search for solutions is gaining momentum. For example, recycled composts, such as food waste and urban green waste, are being trialled as substitutes for mineral fertiliser, while major research efforts on integrated pest management should be able to maintain cereal yield without relying on pesticides. Plant genetics and biotechnology are developing an increasing range of cereal products.

The causes of the problems, and the solutions if they are found, extend far beyond agriculture, however. Crops are just one part of the whole supply chain. Reaching a sustainable future will depend on how human societies balance their needs for agricultural produce with the available energy resource and how they limit and re-use waste. A fundamental shift in attitude to the exploitation of soil and land is needed by people, policy and industry.
 

[Back to top]

 

Sources, references, links, contacts, thanks

Under construction

Books

Lawson P and Son.1852. Synopsis of the vegetable products of Scotland. Edinburgh: Peter Lawson and Son. (Prepared for the Great Industrial Exhibition of all Nations - this privately printed book is an invaluable document of the plant species and varieties grown or tested in Scotland for agricultural use in the middle of the 1800s.)

Sinclair TR, Sinclair CJ. 2010. Bread, beer and the seeds of change. CABI. 193 pages. ISBN: 978 1 84593 704 1 (paperback)

Government Statistics 

Scottish Government web site - Statistical Publication Agriculture Series: (a) Final estimate of the cereal and oilseed rape harvest 2010. This link leads to a table giving the final estimate of cereal area and yield in 2010. The same web pages give recent historical changes and other information. (b) Final results from the 2010 June agricultural census. Areas grown with the different crops in Scotland, with links to data from previous years. Defra provide similar data for the whole of the UK.

Links 

Codex Alimentarius - Cereals, pulses, legumes and vegetable protein: link to a publication from this FAO / WHO body on food standards and codes of practice.

egerbil web page on millets, gives information on the small grained tropical and sub-tropical cereals 

GRAMENE species page, in a web site giving information on the genomes and genetics of grass species (Poaceae); the 'species page' gives information on barley, wheat, etc.

HGCA Home Grown Cereals Authority: a web site with links to information on cereals in the UK.

IENICA Interactive European Network for Industrial Crops and their Applications: a web site funded by the European Commission - includes a searchable database for information on uses of the cereals and other crops 

MAGB Maltsters Association of Great Britain: web site for barley growing, malt, malting, and the malt supply chain.

Scottish landraces and traditional varieties : a web site hosted by SASA (Science and Advice for Scottish Agriculture, previously Scottish Agricultural Science Agency, or more simply 'East Craigs')  gives and seeks information on traditional, heritage and farm-saved seed of cereals such as rye, bere and wheat and other crops.

Thanks

The miller, Rae Phillips at Barony Mills, Birsay, Orkney for samples of bere (barley) meal and grain. The web link leads to descriptions of bere and milling and gives some recipes for cooking with bere meal. The mill is open for visitors - see the web page for opening times.

The Agronomy Institute, Orkney for seed samples of emmer wheat, spelt wheat and bere barley (which the Living Field grew in 2010, and then grew again in 2011 using saved seed).

Mother Gill's Concoctions for advice on making bread, banocks and biscuits from bere, spelt and other heritage cereals.

 

Contacts

Contact at the James Hutton Institute for this page: Geoff Squire,

[Page available from 2 June 2011; under construction, last update 14 December 2011.]

 

[Back to top]


While recording their structure, seeding heads from cereal plants grown in 2010, including emmer, spelt and modern bread wheat, black oat and modern oat, bere barley and modern barley were all stuck into a glass bottle, which was placed on the ledge of a soiled window. The sun dipped low and illuminated 5000 years of cereals.

 [Back to top]