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Our most ancient cultivated grain. barley, was domesticated in Iraq and Syria and was the grain responsible for the agricultural civilization arising in the Tigres and Euphrates River bottoms.
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To learn where barley is grown and why. |
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To understand the special adaptations that give barley an edge over wheat in some regions. |
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To appreciate the role of barley in cropping systems. |
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To understand how barley is utilized, both as a cereal grain and as a popular drink worldwide. |
Barley is a crop that does well throughout the more temperate regions of the world. Barley is one of the most widely distributed of all cereals. Barley does particularly well in cool and semi-arid climates and on fertile well drained soils. Barley prefers higher soil pH and is most susceptible to AL+++ injury of all the cereals. There are two types of barley, two-rowed and six-rowed with the six-rowed the most commonly grown.
This cereal is often grown in rotation after a cultivated crop such as corn, sugar beets, or potatoes. Barley also makes an excellent companion crop (a nurse crop planted with a legume to help with weed control.) Because of the high amount of energy in barley (it contains 95% as much energy as corn), it makes a good animal feed and the best small grain silage. A third of the world’s barley is used in the production of beer. The requirements for malting barley are very ridged, and a special management and environment are necessary for good malting barley.
1. Considered by some to be the most ancient cultivated grain.
2. Domesticated from a wild two row form, Hordeum Vulgade, near the border of Syria and Iraq.
3. First grown in the U.S. off the coast of Massachusetts in 1602 and in Virginia in 1611
1. Barley ranks fourth among major world crops.
2. Production of over 146 million metric tons on 80 million ha of land.
3. Leading countries:
5. Leading states:
1. Spike inflorescence and a zigzag rachis.
2. Short and inconspicuous ligvus and large, conspicuous clasping auricles.
3. Three spikelets/node and, one floret/spikelet with 10-30 nodes/spike.
4. In two-row barley, only one floret (spikelet/node) is fertile.
5. In six-row barley all three are fertile.
6. Each spikelet is subtended by two narrow glumes which may be nearly hairlike.
7. Awns may be smooth or barbed.
8. 10-15% of barley kernel is hull.
10. Grain comes in five colors:
Classes of Barley
1. Three subspecies of cultivated barley.
5. Above classes include both spring and winter types, smooth and rough waned types.
U.S. Production
1. Spring barley grown mostly in:
4. Hulled barley:
6. Hooded varieties used for hay.
7. Naked varieties fed to poultry.
1. Barley is most widely distributed of all the cereals.
2. Is grown throughout the more temperate regions of the world.
3. Thrives in a cool climate.
4. Barley will stand more heat under semi-arid than humid conditions.
8. Yields under dryland conditions surpass those of wheat, oats and rye.
9. Barley is unsuited for acid soils.
Improvement
1. Qualities bred for:
3. 4000 varieties in the world.
4. Breeding for disease resistance has been moderately successful.
5. Winter hardy varieties have extended the winter barley region from Oklahoma to Nebraska.
6. University if Arizona first barley hybrid "Hembar" which yields 15 - 35% more.
Culture
1. Seeded at rate of 6-8 pecks (1 - ½ - 2 bu.)/ac with grain droll.
2. Planted two weeks before the first average frost in the fall.
4. Fall plowing recommended - for disease control.
5. If seeding spring barley (not in Virginia), it should be sown in April as early as possible.
6. Responds to applications of up to 70 lbs./a N when ample soil moisture.
7. Barley yields are increases by K and P improves malting quality.
8. Much of barley is sown in summer fallowed land or following an infertile crop.
Rotations
1. Barley generally makes best growth after a cultivated crop such as corn, sugar beets or potatoes.
2. In humid regions, most practical rotation is of that includes corn, barley, and a leguminous hay or pasture crop. (Use barley as a companion crop for legume.)
3. In South, winter barley occupies the same place as wheat.
1. Barley threshed with a combine.
3. Cut for silage in the early dough stage.
4. In Virginia, barley harvest from June1 to June 20.
5. It yields about 40-75 bu/a grain or 6-8 tons of silage.
Utilization
1. 100 million bu/yr. (30%) used for malt.
3. 25-30 million bu/yr. (10%) used for food.
4. Remaining 240+ million bu/yr. (50%) used for feed.
5. Barley feed value 95% of corn.
7. Some barley is "pearlized" and used in processed foods or as rice substitute.
10. Good winter cover crop.
Malting
1. Rigid specifications for barley. Requires special management efforts.
1. Select cultivar accepted by industry.
2. Early seeding on non-fallow land helps reduce the protein content.
1. Barley is malted in order to produce or activate enzymes which hydrolyze starch into sugars.
Diseases
1. Covered smut.
1. Chinch bug - most important
2. Green bug - resistant varieties
3. Grasshoppers - use insecticides
The Malting Process
Barley is malted in order to produce or activate enzymes which will hydrolyze starch (in the endosperm) into sugar.
1. Soak clean, uniform grain for 2-3 days until the kernels have a uniform moisture content of 44-46%. During this step, the water must be periodically drained. Uniformity in the rate of water uptake is essential. Damaged or skinned kernels are undesirable because they take up water more rapidly.
2. The grain is then drained and transferred to either a rotating drum or a special room where it is spread into a uniform layer about one foot deep. The grain is stirred periodically. The temperature is maintained at 68oF and the grain is allowed to germinate for six days.
4. In brewing, the malt is ground and mixed with water and other grain products that provide additional fermentable materials such as corn grits and broken rice. The mixture is cooked in water in order to gelatinize and liquify the starch.
5. The cooked material is then added to pure malt that has been held in water at 48" C. This temperature favors protein breakdown.
6. The temperature of the new mixture is elevated twice. Once to 65° C, then to 75° C. This completes the conversion of starches into sugars and to denature the proteins. If protein levels are too high, excessive enzymatic activity occurs and lowers the quality of the resulting liquid called the "wort."
7. This "wart" is boiled with hops, drawn off and cooled. It is then fermented with yeast for 7-10 days at 42.8-59°F. The liquid is placed in cool storage (32-41°F) for 3-8 weeks. During this time the proteins yeast cells, and other insoluble settle out The finished beer is carbonated and filtered.
IV. Summary
Barley fits nicely into many crop systems. Grown as a spring grain
in cool climates and as a winter grain in the warmer temperate zone. Of
the small grains, barley makes the best animal feed both as a grain and
silage. Barley prefers the cool/semi-arid alkaline soils of its origins,
but performs well in acid humid soils with lime and fertility. Barley is
used extensively for beer production but malting barley is usually produced
in the semi-arid climates where fungus diseases
are at a minimum. Any damage to the kernel or additional
organism can interfere with the malting process.
V. Self Assessment
Topic
| Learning Objectives | Overview
| Lecture | Summary
| Self Assessment
Last updated January 23, 2008