Barley has the glume and palea (seed coverings) remaining attached to the seed after
threshing. These can only be removed by grinding, to produce “pearl barley”, unlike
wheat which produces a “chaff” of glumes and paleas during threshing. In fact, there
are a few “naked” varieties of barley, which are especially valued as human food.
The information below relates to feed barley types unless otherwise stated.
Although malting barley types are grown in very similar (but normally better)
conditions, farmers have to apply higher standards of crop husbandry to produce
malt quality barley, which also can only be grown on certain soil types.
PLANTING
Propagation: by seed, occasionally hybrid. Almost 100% self-pollinated.
Soil: barley needs less fertile soil than wheat, and adapts to a wider range of soil
types than wheat. More salt tolerant than most other cereals, though some Triticale
and Durum wheat varieties are more tolerant. Soil must not be waterlogged, and
should not be light or sandy or more acidic than pH6 (classified as “sensitive” to soil
acidity).
Fertiliser—similar to wheat; a typical application is 200 kg/ha of 11:54:10 on poor
soil, and 85 kg/ha on more fertile soil. Average UK application for winter barley is
140:75:100. Potash helps to reduce damage from mildew. Malt varieties normally
receive little or no Nitrogen.
Seed rate: dryland 50–70 kg/ha, irrigated 70–120 kg/ha (maximum 200 kg/ha). If
the seed rate is too high there may be too many heads, producing thin, shrivelled
grain. Seed is often broadcast, when more seed is used than with “drilled” (machine
planted) barley.
Seed spacing: 15–25 cm between rows. 28–30,000 seeds per kg.
Depth: 3–5 cm in temperate or humid regions, 5–8 cm in arid and semi-arid regions.
GROWTH CONDITIONS
Day length: long-day, but adapts to varying day length.
Growth period: in general, barley matures earlier than most of the other cereal
crops. The moisture content of seed should not be much above 13% at harvest, if
practical. Winter sown varieties need about 180 days or more to reach maturity,
spring varieties need about 85–120 days.
Rainfall: barley is more drought resistant than wheat, and can grow with 500 mm a
year. Nevertheless, hot and dry conditions lead to premature maturation, leaving thin
seed, with high Nitrogen content. Not suited to warm, humid climates (fungi).
Irrigation increases both seed size and yield, and decreases the Nitrogen content.
Temperature: a cool season crop, barley can grow well vegetatively in cold
weather. Very hot weather also can be tolerated during and after heading provided
that the air humidity is low. Optimum temperature for germination and emergence is
15–20C—the minimum is 2 C.
Rotation: often grown as a monoculture on the same land for many years, in which
case fertiliser is needed to maintain reasonable yields. Can be used as part of an
arable silage mix, with oats, beans, vetches and/or grass.
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108 TONY WINCH
b)Examine the Seed :