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Barley (Hordeum
vulgare L.) French: Orge, escourgeon (winter barley); Spanish: Cebada; Italian:
Orzo; German: Gerste Crop data Annual, winter- and
spring-sown types; ears 2- or multiple-rowed; grains generally with
glumes. Harvested products:
grain, straw, (occasionally) whole green plant. Desired
characteristics affecting fertilizer requirement: In grain for
livestock feed: high crude protein, especially lysine. In grain for
processing for use in human foodstuffs: high-protein endosperm, lack of
excrescences, low husk content. In grain for malting:
high starch, low crude protein, lack of excrescences. Straw for bedding:
should be dry, absorbent material. Whole green plant
for forage: high crude protein and energy, smooth glumes. Sowing times: winter
varieties should have completed tillering before the vegetative rest
period, i.e. normally within 45 days (of real growth) from emergence. On
the other hand, excessive early development of biomass is undesirable as
it reduces winter hardiness. Spring varieties
should be sown as early as practicable, when temperature, moisture and
other soil conditions permit. Plant density:
sowing rates for 2-rowed types are within the range of 320 - 365
grains/m2 (at a desired optimum ear density of 700 - 800
ears/m2). With multiple-rowed winter barley the following
model calculation may serve as a guide: Expected yield = 9
t/ha; required ear density = 600 ears/m2. With an estimated
germination rate of 95 %, an overwintering rate of 85 % and 2.7 ears per
plant, the seeding rate should be 280 grains/m2 (see also 2.3
Wheat). Temperature
limitations and the duration of the various growth phases are
illustrated in the following table
Yield structure: The
next table shows the (relative) changes of yield components in
correlation to varying amounts of plant available water; assuming that
water supply is the primary yield-determining factor in cereals:
The grain yield of
barley is related to the amount of water consumption, which increases
over-proportionally with increasing yield; the same is true of N uptake.
If maximum utilization of water and applied nutrients is required for
optimum grain yield, then the ratio of the number of plants per unit
area to the number of ears per plant must be optimized; thus the crop
should tiller heavily. This can be influenced, depending on water and N
supply, by application of N. Depending on the quantity and timing of N
application, around 250 l water per kg grain yield may be needed, the
coefficient of productive tillering (ear-bearing tillers / total
tillers) ranging between 0.39 and 0.60. As shown in the
figure it is not so important in barley as in wheat to control the
uniformity of different orders of tillers. Unproductive tillering
(caused for example by a too high or too late N fertilization in spring)
should, however, be avoided.
Two-rowed barley
varieties have lower ear weights, consequently a higher ear density than
with multiple-rowed types is necessary to reach the same yield. Higher
seeding rates and productive tillering promoted by N-fertilizer use are
therefore necessary with two-rowed types (e.g. 700 - 800 ears/m2 as
compared to 550 - 600 ears/m2 on fertile soils with ample water supply).
With multiple-row types the target should be about three ears per plant,
and with spring-sown two-row types two ears per plant. Because of the
importance of floret reduction and grain formation in two-row types, an
adequate nutrient supply must be ensured during shooting and after
flowering. When the crop is
grown for malting, a variety should be selected which is appropriate to
the expected wheather conditions. If the crop is
undersown, the undersown crop should not be grown so early that it might
outgrow the barley and reduce resistance to lodging. Nutrient demand/uptake/removal
Fertilizer recommendations The same principles
apply as for wheat, but the exact timing of split applications of N is
more critical, especially for winter barley. Since the root
system of barley is less readily established than that of wheat,
attempts have been made (in the UK) to promote longitudinal root growth
by autumn application of clormequat chloride to young plants; but the
efficacy of this method has not yet been fully confirmed. Owing to the greater
tendency of barley to lodge, as compared with wheat, stem stabilizers
are being used in intensive growing systems. As chlormequat by itself
does not give sufficient reduction in stem length, a combination of
chlormequat chloride and etephon is favoured, with etephon alone being
used for late applications. Preferred forms of fertilizer
nutrients N -
Quick acting forms are preferred for malting barley; forms releasing N
too late in the growing period should be avoided in order to minimize
the risk of too high a crude protein content in the grain. Slurry in
particular can cause serious problems; if used at all for malting
barley, only small amounts should be applied. Too late application of N
fertilizer should be avoided. P -
a good supply is especially important for malting barley. K -
potassium chloride. As for P, adequate K should always be available. In
general, K increases lodging-resistance and frost-hardiness. Mg -
barley reacts intensively to deficiency, producing leaf chlorosis; even
though this may not always significantly reduce yield, it should be
corrected by application of adequate Mg-containing fertilizers. For further
details refer to 'Fertilizer recommendations' and 'Calculation of
nutrient rates' for Wheat. Click
here. Generally, for the
application of P and K three methods are practised:
On soils with
satisfactory reserves of P and K, the applied nutrient rates depend on
the expected grain yield.
Fertilizer practice in other
countries Canada Most barley produced
in Canada is spring seeded. It is grown both for feed and malting
purposes, with small amounts used for human consumption. Fertilizer
recommendations vary from region to region, depending on environmental
conditions. Soil testing is recommended for specific fertilizer
recommendations. In drier areas, band
application of N is generally recommended. Limited amounts of N may be
placed with the seeds. In the moister areas, spring broadcast and
incorporated fertilizer applications are quite efficient. In all areas P
should be seed-placed or banded with N. K is also more efficiently used
if banded than if broadcast. Limited amounts (less than approx. 35 kg/ha
K2O) can be placed with the seeds. Alberta
Manitoba
Sasketchewan
India
P should be placed 5
cm below the seed; application rates are adjusted according to soil test
results. Further reading COMMONWEALTH AGRICULTURAL BUREAU:
Barley: soil, water and nutrient relations (1974-1966). CAB Annotated
Bibliography No. 1718 (1975) GAUER, E. et al.: Nitrogen
Fertilization of Barleys in Manitoba. Canada Agri. Food, Manitoba,
Agriculture No. 100 (1990) RASMUSSON, D.C.: Barley. ASA Monograph
26, Madison, WI, USA (1985) REINER, L. et al.: Wintergerste
aktuell. DLG-Verlag, Frankfurt a.M., Germany (1977) REINER, L. et al.: Sommergerste
aktuell. DLG-Verlag, Frankfurt a.M., Germany (1985) Authors: K.-U. Heyland, A. Werner;
Lehrstuhl fuer Speziellen Pflanzenbau und Pflanzenzuechtung, University
of Bonn, Germany Contributors: L.D. Bailey, C.A.
Grant, Research Scientists, Agriculture Canada, Brandon Research
Station, Brandon, Manitoba, Canada; R. Prasad, Professor of Agronomy,
Indian Agricultural Research Institute, New Delhi, India |
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