Spring barley

Economic importance

In Russia, spring barley is cultivated as a food, industrial, and fodder crop. Flour, barley groats, and pearl barley are produced from coarse-grained and vitreous barley grain. For bread baking, barley flour is of little use because of poor gluten quality; therefore, sometimes, in the Far North, where it is one of the main cereal crops, it is mixed (up to 10–15%) with wheat or rye flour. Bread made from pure barley flour is weakly porous and stales quickly.

Spring barley has excellent fodder properties; average composition: water — 13%, protein — 12%, fat — 2.1%, nitrogen-free extractives — 64.4%, ash — 2.8%. 1 kg of grain equals 1.28 feed units. Straw and chaff of barley are also used as roughage; they are readily eaten by animals when steamed. 1 kg of straw equals 0.35 FU.

Barley can also be used as a coffee substitute, in the production of malt extracts, and in the alcohol and confectionery industries. For brewing, two-row varieties are considered most valuable, producing large, uniform grain with low protein content up to 9.0–12.5%, low hull content — 8–10%, and high germination energy — up to 95%.

In southern Russia it is used for green fodder and hay in grass mixtures with vetch, vetchling, peas, and other crops.

Cultivation areas and yield

Spring barley is drought-resistant, early-maturing, heat-tolerant, and cold-resistant. Its crops are distributed from the Polar region (up to 68° N) to southern regions, but the largest share of sowing is concentrated in the steppe regions of the North Caucasus and in the Central Chernozem zone. Due to its ability to withstand air drought, its crops are distributed in the South-East of Russia, Kazakhstan, and Kyrgyzstan.

In world agriculture in the 1980s, this crop occupied about 76 million ha; in the 1990s — 65 million ha, or 9% of the cereal sown area. Gross grain harvest is about 150 million t, or 7% of total grain harvest. Average yield is 2.3 t/ha. Crops are distributed in Western Europe, North America (USA, Canada), Central America, and Asia (China, India, Asia Minor countries).

In the USSR, barley crops in 1982 were over 32 million ha; in 2001–2005 in Russia — 10.2 million ha (22.6% of cereal area), including 9.6 million ha under spring barley. Gross harvest — 18.4 million t, including spring — 16.4 million t. Average yield of winter barley — 3.44 t/ha, spring — 1.92 t/ha (1997 — 1.62 t/ha). Under intensive technologies, potential yield can reach 4–7 t/ha.

On the territory of the former USSR, three cultivation zones can be distinguished:

• northern — food barley;
• southern — fodder and export barley;
• western (Belarus, forest-steppe zone of Ukraine, northwestern regions of Russia, Baltic countries) — malting barley.

The division is conventional, since zoning does not exclude the universal use of barley. However, the requirements imposed on barley, primarily malting barley, are better satisfied in the western zone, where grain is rich in high-molecular-weight proteins and most suitable for brewing. In mountainous regions of Russia, its crops rise to an altitude of up to 3000 m above sea level.

Among spring cereals of group I, spring barley gives the highest and most stable yields. Average yield for 1976–1980 in the USSR was 1.61 t/ha; on individual farms it reached 7.0 t/ha, which indicates the possibility of obtaining high yields in all regions of the country.

Botanical description

The genus Hordeum L. includes three species of cultivated barley (Hordeum vulgare syn. Hordeum sativum Jessen.): two-row barley (Hordeum distichon L.), multi-row barley (Hordeum vulgare L.), intermediate barley (Hordeum intermedium Vav. et Orl.footnote:[Probably the species Taeniatherum caput-medusae of the genus Taeniatherum is meant]), as well as many species of wild barley.

Mass of 1000 grains — 30–60 g. Vegetation period — 65–110 days. It is the earliest-ripening crop among cereals of group I. It belongs to long-day plants. It tillers more strongly than spring wheat and oats.

The root system is fibrous. The stem is a hollow culm, 55–100 cm high. The leaf blade is somewhat wider than in wheat. The ligule is short; the auricles are large, without cilia, and when clasping the culm they overlap each other. The inflorescence is a spike. The spike is awned, except for the furcate type, in which instead of awns there are three-lobed appendages. The awns are longer than the spike and arranged parallel.

The spike color is yellow, rarely black. The grain is wide, laterally compressed, has a furrow, without a crest, hulled, rarely naked, elliptical, and pointed at the ends. The caryopses fuse with the lemma. The color of hulled grain ranges from yellow to light yellow.

Hull content in two-row barley is 9–11%; in multi-row — 10–13%. Grain in multi-row barley differs in size: lateral grains are smaller and slightly curved at the base.

Self-pollinating. In dry and warm weather, it flowers before the spike emerges from the leaf sheath.

By the number of fertile spikelets on the rachis segment, barley is divided into:

1. Multi-row barley (Hordeum vulgare L.), or common barley. On each rachis segment there are three fertile spikelets, which develop and produce grain. Depending on spike density, multi-row barley is divided into:

• group of regular six-row (six-sided) barleys hexastichum L., with a dense, thick, relatively short spike, which in cross-section has the form of a regular hexagon;
• group of irregular six-row (four-sided) barleys tetrastichum Korn, with a less dense spike; the rows of grains are not quite regular, the lateral spikelets overlap each other, the middle spikelets are more developed than the lateral ones, the spike has two wide faces on the front side and two narrow ones on the side, and in cross-section has the form of a quadrilateral.

2. Two-row barley (Hordeum distichon L.). Of the three spikelets located on the rachis segment, only the middle ones bear fruit; the lateral ones are sterile. Two-row barleys, by the character of the sterile spikelets, are divided into:

• nutanita R. Red, in which the lateral sterile spikelets have lemma and glumes;
• dificientia R. Red, in which the sterile lateral spikelets consist only of glumes. In crops, two-row barleys are only nutanita; dificientia barleys occur as impurities, usually in Transcaucasia.

3. Intermediate barley (Hordeum intermedium Vav. et Orl.). On the ledge of the spike rachis, normally from one to three grains can develop.

In Russia, multi-row and two-row subspecies are widespread. Multi-row barleys are usually more early-maturing and drought-resistant than two-row barleys; therefore, they are cultivated from the Far North to the South and South-East.

Each of the first two species of barley is divided into varieties by the following traits:

• awnedness — awned or awnless — three-lobed appendages;
• character of awns — dentate or smooth;
• color of spike and caryopsis — yellow or black;
• hulliness of grain — hulled or naked;
• spike density — dense (more than 15–18 segments per 4 cm of rachis length) or loose (7–14 segments).

In our country, 20 varieties of barley are represented. The largest sown areas are occupied by nutans among two-row barleys and pallidum among multi-row barleys. Also of interest are awnless, or furcate, barleys: horsfordianum — multi-row spikes, yellow, hulled grains; trifurcatum — multi-row spikes, yellow, naked grains. However, varieties of these varieties are not grown in Russia, as they are characterized by low yield and instability to unfavorable conditions.

Varieties of naked barley are distinguished by increased protein content; therefore, they are used for the production of groats, barley coffee, and flour. In Russia they are almost not grown.

Biological features

Spring barley is well adapted to various soil-climatic conditions.

Vegetation

During germination, 5–8 roots form, but the root system is weak. During tillering, which occurs 18–20 days after emergence, 4–5 stems form, 2–3 of which are productive. In arid conditions, it begins to flower before the spike emerges from the leaf sheath. Flowering ends before full heading.

Crop rotation

The best preceding crop for spring barley is considered to be row crops (maize, potato, sugar beet), under which, as a rule, fertilizers are applied. Good ones also include winter crops following fertilized clean fallow. It is allowed to sow after spring wheat if it follows a layer of perennial grasses or clean fallow.

Spring barley sown after row crops is most suitable for brewing. In this case, it gives a high yield of good quality with high starch content.

For food or fodder purposes, spring barley is sown after grain legumes. In beet-growing areas, a good preceding crop is sugar beet.

According to data from the Poltava Agricultural Experimental Station, the average barley yield over 17 years after potato was 2.1 t/ha, after maize — 1.96 t/ha, after flax and beet — 1.75 t/ha, after spring wheat — 1.7 t/ha, and after barley — 1.53 t/ha.

Due to its early maturity, spring barley serves as a good preceding crop for spring crops, and in some areas for winter crops. Thus, in areas with sufficient moisture in Krasnodar Krai and Nizhny Novgorod Oblast, after spring barley winter wheat is sown. Due to early harvesting dates, barley is used as a cover crop.

Fertilizer system

Due to its short growing season and low absorbing capacity of roots, it is more demanding of mineral nutrition. Mineral fertilizers increase productive tillering; however, excess nitrogen leads to lodging.

For the formation of 1 t of grain and the corresponding amount of straw (1.4 t), 25–30 kg nitrogen, 11–12 kg phosphorus, and 20–28 kg potassium are consumed. The greatest consumption of nutrients occurs in the initial phases of development. In the period from emergence to tillering, up to half of the phosphorus and nitrogen and almost 3/4 of the potassium of their total used during vegetation are consumed.

The greatest nitrogen consumption occurs at the beginning of tillering — stem elongation; its deficiency in this period leads to disruption of spike formation. Potassium increases the strength of the straw, drought resistance of plants, and resistance to diseases, and affects the reutilization of plastic substances from vegetative organs to the spike.

Direct application of manure under spring barley is practiced in northern regions, where it is the main cereal crop. In other regions, it is sown as a second crop, since it well utilizes the aftereffect of manure. Doses of manure for the Non-Chernozem zone (under deep autumn tillage under the preceding crop) — 30–40 t/ha; forest-steppe and steppe zones — 15–20 t/ha.

Phosphorus and potassium are applied under autumn plowing; nitrogen under pre-sowing cultivation and in top dressing.

The application of phosphorus and potassium fertilizers helps improve the brewing qualities of barley. The best yield is obtained with the application of a complete mineral fertilizer, especially in western regions. In Belarus, with the application of complete fertilizer, the yield increase is up to 6 c/ha; in Perm Oblast — 5.1 c/ha.

On podzolic, gray forest soils, degraded or podzolized chernozems, spring barley responds well to the application of nitrogen and phosphorus fertilizers; on drained bog soils — to potassium. In the zone of serozems and chestnut soils, nitrogen and phosphorus fertilizers are of great importance; on thick chernozems — phosphorus-potassium fertilizers.

Types and doses of fertilizers are established taking into account the available nutrient reserves in the soil, the planned yield, and the coefficients of nutrient use.

Approximate doses of mineral fertilizers: N_20-30P_45-60K_25-40. On soils poor in organic matter, the rate of nitrogen fertilizers is increased. Under conditions of sufficient moisture, the maximum nitrogen dose is 90 kg/ha. When cultivating barley for brewing after cereals and row crops, the nitrogen dose is respectively 60 kg/ha and 30 kg/ha.

When cultivating fodder barley using intensive technologies, fertilizer rates recommended in the Non-Chernozem zone are N₈₀P₇₀K₇₅; in the Central Chernozem zone — N₉₀P₉₀K₉₀. They are applied under the main treatment and pre-sowing. The efficiency of band application of fertilizers to a depth of 12–16 cm has been noted.

Row application of granular superphosphate P_10-20 at sowing allows increasing the efficiency of phosphorus fertilizers. Phosphorus row fertilizer promotes the development of the root system and increases resistance to unfavorable conditions, affects the consumption of other nutrients, and accelerates the formation of generative organs and ripening of grain.

Row phosphorus fertilizer P_10-20 and nitrogen top dressings N₃₀ in the stem elongation phase are effective when growing fodder barley. Nitrogen doses should be corrected taking into account leaf diagnostics.

For normal growth and development of plants, micronutrient fertilizers are also used:

• boron — on limed soils;
• manganese;
• zinc — on soils rich in mobile phosphorus;
• copper — on peat soils;
• molybdenum — on acid soils with pH less than 5.2.

Deficiency in the soil of any microelement leads to increased disease damage, disruption of metabolism in plants, and reduced yields. The need for micronutrient application should be established based on soil diagnostics results.

On drained peat soils, application of copper sulfate at a dose of 25 kg/ha and pyrite cinder at 5 c/ha increases the yield of spring barley. The aftereffect of copper fertilizers manifests within 3–4 years.

Micronutrient fertilizers are also used in pre-sowing seed treatment and foliar top dressing. Per 1 t of seed material, 100 g boron, 120 g zinc, 180 g manganese, 300 g copper, and up to 750 g sodium humate are consumed.

On acid soils, liming is carried out.

Fertilizer rates are determined by the removal of nutrients with the harvest, or per yield increase using correction coefficients for mobile phosphorus — 0.5–0.7, for exchangeable potassium — 0.6–0.8, for nitrogen — 0.7–0.8 (in the Non-Chernozem zone — 0.5), based on an agrochemical soil survey.

Soil tillage system

In most regions, early autumn plowing with plows with skimmers to a depth of 20–22 cm is usually used. On heavy and waterlogged soils, additional chiseling to a depth of 40–50 cm is carried out. After stubble predecessors, stubble disking is carried out before plowing. On heavily infested rhizomatous weeds in sod-podzolic and gray forest soils of the European part of Russia, several treatments with disk implements are carried out.

On chernozem soils of the steppe zone, preference is given to heavy cultivators with spring working organs. Treatment is carried out to a depth of 10–12 cm, followed by plowing with plows with skimmers to a depth of 25–30 cm. When root-sprouting weeds spread, the first treatment is performed with moldboard disk harrows. After row crops, deep plowing with a plow or surface treatment with heavy disk harrows is carried out.

In regions with a risk of wind erosion, flat-cut treatment is used. Heavy soils by soil texture are treated to a depth of 25–27 cm; light — to 12–14 cm; solonetzic and compacting — by chiseling. To prevent the development of water erosion, treatments are performed across the slope; additionally, slitting is carried out.

Spring barley is responsive to deep autumn soil tillage. In Poltava Oblast of Ukraine, deepened plowing of autumn tillage to 30 cm allowed obtaining a yield increase of 2.8 c/ha compared with usual plowing. A good result is given by deepening of the arable layer on sod-podzolic soils with simultaneous application of manure and mineral fertilizers.

On plots intended for sowing spring barley in the winter-spring period, snow retention is used.

Spring soil treatment consists of harrowing or smoothing of autumn tillage. Early spring treatment of autumn tillage is performed with heavy tooth harrows. With flat-cut autumn treatment, needle harrows are used in spring. Pre-sowing cultivation is carried out to the depth of seed sowing (5–7 cm), followed by harrowing; in this case, on plowing — with ordinary or beet cultivators, with flat-cut treatment — with erosion-control ones.

Sowing

Seed sowing depth

Seed sowing depth on heavy clay soils is 3–4 cm; on light sandy loam — 5–6 cm; in dry years and under conditions of rapid drying of the sowing layer — 6–8 cm.

Because disk openers of seeders become clogged in wet soil, the use of anchor ones allows sowing to begin somewhat earlier. Their use allows more uniform sowing of seeds. For sowing, depending on soil-climatic conditions, grain, narrow-row, and stubble seeders can also be used.

Swelling of sown barley seeds proceeds slowly; therefore, they are necessarily embedded in a moist, slightly compacted soil layer.

Crop care

Crop care techniques include post-sowing rolling, harrowing, and protection of plants from weeds, diseases, and pests.

To ensure uniform seedlings and improve thermal and water regimes, in arid conditions post-sowing rolling is carried out with simultaneous light harrowing, or in a unit with seeders during sowing (in wet soil, so that soil does not stick to rollers — one day after sowing).

In moist regions on heavy soils, harrowing over seedlings is carried out, which helps destroy weeds, loosen the soil, and increase aeration of the upper layer. After heavy rains before emergence, when a soil crust forms, harrowing is carried out to destroy it.

For weed control, the herbicide amine salt of 2,4-D is used at a rate of 0.6–1.0 kg/ha a.i.. Herbicide treatment is carried out in the phases of full tillering — beginning of stem elongation. According to experiments of the crop production laboratory of the MAA named after K. A. Timiryazev, herbicide treatment destroys up to 98% of weeds in barley crops; yield increases from 18.6 to 21.2 c/ha.

In the tillering phase, it is recommended to harrow crops for mechanical weed control and to destroy the soil crust.

Pesticides are applied with ground sprayers or by aviation. The working fluid consumption rate is respectively 200–300 L/ha or 50 L/ha.

Plant protection

Harvesting

Ripening of spring barley usually proceeds uniformly. With the onset of full ripeness, the spike becomes brittle and droops; the grain easily shatters.

The two-phase harvesting method is used from the middle of ripeness at grain moisture 28–30% and is completed at moisture 20–22%. Delay with threshing windrows is not recommended for more than 5–6 days. The single-phase method is used at full ripeness and grain moisture 15–17% at a low cut in a short time.

At the threshing floor, homogeneous lots are formed separately by grain quality of fodder and malting varieties.

Features of cultivating malting barley

For brewing, two-row barleys are used, which produce large, uniform, evenly germinating grain. Hulled varieties are most suitable, since the hulls during filtration promote clarification of beer.

Barley grain for brewing should have a mass of 1000 grains of 40–45 g, be thin-hulled (not more than 9%), straw-yellow in color with germination energy not less than 95%, and contain over 78% starch. There was an opinion that only grain with low protein content is suitable for brewing; however, it has been established that the main significance is not the content but the quality of proteins. According to studies, the best results are given by barley containing high-molecular-weight proteins — globulins and prolamins, poorly soluble in water. A negative influence on beer quality is exerted by non-protein nitrogen and albumin nitrogen.

The best preceding crops for malting barley include winter cereals, maize, potato, sugar beet, and flax.

Optimal are the earliest sowing dates, ensuring a high yield of uniform, large grain with high starch content and reduced hull content.

Fertilizer rates are determined taking into account the planned yield, removal of nutrients, and their content in the soil.

Optimal sowing methods are narrow-row and cross.

A good result is given by post-sowing rolling; with strong soil compaction or formation of a crust — harrowing of crops. These techniques promote the formation of uniformity of the stand and grain uniformity. Late tillers in malting barley crops are undesirable, as the grain is smaller with low technical qualities.

For harvesting, the single-phase method is used in the period of full ripeness at grain moisture not more than 22% using two-drum combines. In southern regions, the two-phase harvesting method is more often used.

Overstanding of barley leads to a decrease in starch content due to increased respiration. Excessive moisture and low air temperature during full ripeness of grain negatively affect the viability of seeds of later harvesting dates.

After threshing, grain is sorted and dried, which ensures high germination energy and preservation of light color.

Spring barley varieties

In crops, varieties of two-row barley predominate. They shatter less during overstanding, better suit mechanized harvesting, and are usually more productive. Among two-row varieties, the following are widespread:

Donetsk 4 (v. medicum). The variety was bred by the Donetsk Agricultural Experimental Station. Mid-season, high-yielding, resistant to lodging. Resistant to loose smut and rust. Groats and fodder qualities are good. Zoned in Altai, Krasnodar Krais, Volgograd, Orenburg, Saratov, Ulyanovsk Oblasts, Tatarstan, Ukraine, and Kazakhstan.

Moskovsky 121 (v. nutans). The variety was bred by the SRIA of the Central Regions of the Non-Chernozem Zone. Mid-season, high yield. At a yield of 3.0–3.5 t/ha it lodges. Moderately affected by loose smut and dwarf rust. Zoned in the Non-Chernozem zone, Belarus, and Zhytomyr Oblast of Ukraine.

Odessa 36 (v. nutans). The variety was bred by the All-Union Breeding and Genetic Institute. Mid-early, drought-resistant, resistant to lodging and shattering. Moderately affected by loose smut. Zoned in Krasnodar, Stavropol Krais, Samara, Kurgan, Chelyabinsk, and Rostov Oblasts.

Krasnoufimsk 95 (v. nutans). The variety was bred by the Krasnoufimsk Breeding Station. Mid-season, high yield; resistance to lodging and loose smut is average. Grain has high brewing and good groats qualities. Zoned in Amur, Kaluga, Kemerovo, Kurgan, Sverdlovsk, Chelyabinsk Oblasts, Udmurtia, and Tuva.

Among multi-row barleys, the following varieties are widespread:

Pallidum 45 (v. pallidum). The variety was bred by the Krasnokutsk Experimental Breeding Station. Zoned in the Lower Volga, Krasnodar Krai, Dagestan, Chechnya, and Ingushetia.

Polyarny 14 (v. pallidum). The variety was bred by the Polar Experimental Station of the All-Union Institute of Plant Industry. Very early-maturing, undemanding to heat. Zoned in the northern regions of Arkhangelsk Oblast, the Komi Republic, Yakutia, and Kamchatka Oblast.

List of sources

1. Vavilov P. P., Gritsenko V. V., Kuznetsov V. S. et al. (1986). Plant Production. Edited by Vavilov P. P. 5th ed., revised and enlarged. Moscow: Agropromizdat.
2. Kolomeichenko V. V. (2007). Plant Production/Textbook. Moscow: Agrobusinesscenter.
3. Niklyaev V. S. (2000). Fundamentals of Agricultural Production Technology. Agriculture and Plant Production. Moscow: Bylina.