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Oats

Oats are a grain crop, belonging to the spring cereals of Group I.

Oats (Avena sativa)
Oats (Avena sativa)
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©Rasbak (CC BY-SA 3.0)

Economic importance

On average, oat grain contains 10-13% protein, 40-45% starch, and 4.5-6.0% fat. Due to these indicators, oats are of nutritional and fodder value. Oat grain is an irreplaceable concentrated feed for horses and young stock of other animal species and poultry. Oats as a fodder help to increase the egg production of chickens and increase milk yields. The nutritive value of 1 kg of oat grain of average quality is taken as 1 feeding unit.

It is used to produce groats, oat flakes, tolokno, cookies, coffee. Due to the good digestibility of protein, fat, starch and vitamins, oat products are important in dietary and children’s diets. Grain is rich in vitamins (B1, B2) and trace elements (cobalt, zinc, manganese).

Oat groats due to their high calcium and phosphorus content are superior to millet and buckwheat in terms of nutritional value. Oat flour is not used for baking because of the low quality of gluten, but it is used to make cookies.

Oat straw and chaff are used as animal feed and are nutritionally superior to straw and chaff from other grains. Straw contains 3.9% protein, 1.9% fat, 33.9% fiber and 38.5% of nitrogen-free extractives. The vetch-oat mixture is the best crop for sowing in seeded fallow. In conditions of sufficient moisture in mixtures with leguminous grasses, for example, vetch, chickpeas, peas, it is used for getting green mass, hay, haylage.

History

Oats are one of the oldest crops. According to N.I. Vavilov, oats were cultivated later than wheat and barley.

Initially, it was found as a litter for wheat and barley crops. As these crops moved north and into the mountains, oats displaced them because of their hardiness to the growing conditions and were incorporated into the crop.

In Europe, oats have been known since 1500-1700 B.C. In ancient Greece it was first mentioned in the sixth century before Christ. On the territory of Russia it began to be cultivated in the northwestern areas of the Non-Black Earth zone from the 7th century A.D.

Planted areas and yields

Oat was the seventh most sown crop in the world in the 1980s, or 26.3 million hectares; in 1997 it was 20 million hectares.

In the USSR in 1982 the sown area amounted to 11.5 mln ha. At the end of the last century, the area under crops in the world fell to 16 million hectares, or 2.3% of the total area of cereal crops. The gross output is 30 mln tons with an average yield of 1.9 t/ha.

This crop is cultivated in Western Europe, the USA and Canada. In Europe it is cultivated from Norway (69°N) to the south of France.

In 1997 the sown area of oats in Russia was 6.4 million ha at the yield of 1.46 t/ha. In 2001-2005, the total area under oats in Russia amounted to 4 mln ha or 9.1% of the total area. – In the years 2001-2005, the total area under oats in Russia was 4 million ha or 9.1% of the total area under crops. The gross output in 2001-2005 was 6 million tons (7.4% of the total grain production) with an average yield of 1.65 t/ha.

In Russia, the main areas sown are in areas with sufficient moisture, especially in Kirov, Perm, Chelyabinsk, Tula, Ryazan, Novosibirsk, Omsk regions, Bashkiria, Tatarstan, Altai and Krasnoyarsk territories. In addition, large areas of oats are sown in Belarus, Lithuania, the north of Kazakhstan, the Polesie and the forest-steppe of Ukraine.

In Russia, oat crops are located up to the Arctic Circle slightly below the barley border, in Siberia sometimes the borders coincide.

The maximum yield of oat grain, for example, is 5.5 t/ha in Kaluga Oblast, 4.9 t/ha in Moscow Oblast, 4.3 t/ha in Penza Oblast, and 7.6 t/ha in Kemerovo Oblast.

Botanical description

Plants of the genus Avena L. have a spreading or compressed panicle, 2-3-flowered or multiflowered spikelets. Spikelet scales are webbed, usually longer than or equal to flower scales. Spikelet forms have mainly crankly curved and twisted at the lower knee, departing not from the tip but from the back of the flower scales. The grain is covered over its entire surface with soft pressed hairs.

The weight of 1,000 seeds is 27-46 g, while the proportion of membranes in the grain (filminess) is 22-30%. Grain is elongated, narrowed, pointed toward the apex, with a tuft and a groove, softly hairy on the surface. The color of filmy forms is white, yellow, or brown; that of holo-grain forms is light yellow. Self-pollinating crop.

Root system is fibrous, well developed. Stem is hollow, 70-100 cm high. The uvula is well developed, serrated along its upper edge. The auricles are absent.

Oats are represented by more than 70 species, including perennial and annual, cultivated and wild forms, of which only 11 species are of practical importance.

Two species are cultivated in Russia: sown (Avena sativa L.) and Byzantine (Avena byzantina S. Koch.). Also grow sand oats (Avena strigosa Schreb.) and wild oats (Avena fatua L., Avena ludoviciana Dur.), which are weed plants in crops of cereals and other field crops.

Common oat

The common oat (Avena fatua L.) is widespread in the northern regions, so it is called a northern oat, and the Ludovician oat – in the southern regions and is called a southern oat.

In contrast to the cultivated bunches, wild oats have a special articulation at the base of the grain, the horseshoe, which appears as a result of growth and thickening of the base of the lower blossom scale. Cultivated oats do not have this horseshoe. It causes shattering of the oat’s seeds even in a green state. Common oatmeal has a horseshoe on each grain in an ear, while southern oatmeal has a horseshoe only on the lower one. The colored scales of the common oatmeal are covered with dense hairs with a coarse developed point, which can twist and untwist depending on humidity, thereby contributing to the deepening of the seeds in the ground.

Common sowing oats

Common sowing oats differ from Byzantine oats in that the ear breaks apart during threshing. In sowing oats, the second kernel breaks off at the top of its stalk, which remains with the lower kernel. The break area of the lower kernel is straight. The spikelet awn is single or absent. Almost all varieties cultivated in Russia and the former Soviet Union belong to this species.

The second kernel of the Byzantine oat cracks at the bottom or in the middle, partly retaining the top kernel, partly retaining the bottom one. The break area of the lower grain is somewhat oblique.

Sand oats

Unlike the first two species, sand oats are characterized by long spicules (struts) at the apex of the outer flower scale. The lower flower in the spike sits on a stalk; the spikelets are provided with two coarse cranked-curved spikes. This type of oat grows on light sandy soils, so it is called sandy. In Russia it is recognized as a weed.

Varieties

Common sown oats are represented by filmy and holo-grain forms. The filmy forms occupy the largest areas, while the holo-grain forms are less common due to their lower yield. Spikelets of holo-grain forms are large, multifloral (more than five flowers); glumes and spikelet scales are membranous (soft). Flower scales of filmy oats are more rigid and leathery. Grains of holo-grain oats fall easily out of the floral scales during threshing. They are more damp-demanding than filmy oats.

According to the structure of the panicle, common oats are divided into spreading (diffusae Mordv.) and compressed, or one-mane (orientalis Mordv.). Oats with a spreading panicle, the branches of which are directed in different directions, are the most widespread. The panicle of the one-mane ones is unilateral, with the shortened twigs pressed against the panicle stem.

Depending on the type of panicle, the color of the floral scales (grains) and the presence of awns, the oats are divided into varieties.

In Russia the cultivated varieties are: mutica Al. Korn, aristata Kg. The most widespread are white-grain oats, characterized by large grains and coarse straw. The kernels of yellow-grain oats are shallower, with a smaller proportion of scales. It differs from white-grain oats by a greater content of fats and vitamins, and it is more drought-resistant. Gray-grain oats (varieties grisea Korn and cinerea Korn) are mostly wintering, cultivated in the south of Europe, in Russia – in the foothills of Crimea. Brown oats (varieties brunnea Korn and montana Al.) are of interest for cultivation in the dried bogs of the Non-Black Soil zone. The one-grain varieties are characterized by late maturity and resistance to dust bunt, ripen more evenly, and shatter less.

Holo-grain oats are represented by two common varieties with bifurcate panicles and white flower scales: the awnless (inermis Korn) and spinous (chinensis Fisch) varieties.

Biological features

Temperature requirements

Oats are a plant of temperate climates. Seed germination temperature is +1 … +2 °C. The optimal temperature for sprouting and tillering period is +15 … +18 °C. Sprouts tolerate short spring frosts of -3 … -9 °C. As plants develop, they become less resistant to low temperatures. During flowering, night frosts under -2 °C are destructive. By the phase of grain ripening, cold sensitivity is somewhat restored, and the grain tolerates frosts to -4…-5 °C.

The sum of active temperatures during the growing season for early-ripening varieties is 1000-1500°C, for mid-ripening varieties it is 1350-1650°C, for late-ripening ones it is 1500-1800 °C.

As a result of the rapid development of the root system, the plants suffer less from spring drought than spring wheat and barley. On the contrary, it is less resistant to high temperatures and summer air droughts. At temperatures of 38-40 °C and air dryness, stomatal paralysis occurs in 4-5 h.

Moisture requirements

Oats are moisture-loving plants. Oats require more water for swelling than holo-grain varieties, absorbing 60-65% of water from the weight of the grain, while barley requires 50% and wheat 45%. According to the South-East Research Institute of Agriculture, the transpiration coefficient is 474, according to other data it is 400-665.

The critical period of moisture consumption is from the emergence of the tube to the formation of the panicle. The deficit of soil moisture 10 to 15 days before the formation of the panicle is especially destructive and leads to a sharp decrease in yield. Oats give the greatest yields in years with sufficient precipitation in the first half of summer. Rainy weather in the second half of the summer in northern areas leads to formation of undergrowth (regrowth of new shoots from the tillering node) and prolongs the vegetation period, which leads to the fact that oats do not have time to mature before the onset of frost.

Soil requirements

Oats are less soil-demanding than other early spring cereal crops due to their developed root system with high digestive capacity. Oat roots penetrate to a depth of up to 120 cm and spread to a width of up to 80 cm. The root system has the ability to extract nutrients from hard-to-reach compounds.

Oats can grow on sandy loam, loam, clay, peat soils. Cohesive soils with a high content of nutrients, including in poorly soluble form, are suitable for it. Of all cereals, it does well on acidic soils with a pH of 5-6 and on drained peatlands. Therefore in the Non-Black Soil Zone it may be the first crop after raising virgin lands or forest clearings.

Oats respond well to lime treatment of acidic sod-podzol soils. Saline soils are of little use.

Light requirements

Long-daylight culture. Shade tolerant.

Vegetation

Vegetation phases:

  • sprouting;
  • tillering;
  • emerging into the tube;
  • panicle formation;
  • grain ripening.

The vegetation period is 75-120 days.

Nodule roots begin to form 7 to 10 days after sprouts appear. Even after a dry spring, if there are rains in June, the plants are able to continue to bush and form nodular roots in summer.

The tillering intensity is lower than that of barley. The total bushiness is 3-4 shoots, the productive one is 1.5-2.

Crop rotation

Row and legume crops are considered good predecessors for oats. Since oats are nitrogen-demanding, legumes are good predecessors for them. Increase in yield grain oats sown after peas is at least 0,2-0,3 t / ha.

Oats produce good results when placed after winter crops sown on fertilized fallows. In the Non-Black Soil Zone, potatoes and fiber flax are valuable predecessors.

In Siberia, the Urals, the Far East, spring wheat following fallow or perennial grasses, barley, row crops often serve as predecessors of oats.

It is not recommended to sow oats after beets, as it leads to the spread of a common pest for these crops – nematodes. Repeated sowing two years in a row is poorly tolerated.

Thanks to its low sensitivity to soil acidity in the Non-Black Soil Zone, it is usually sown as the first crop in the development of marsh soils.

Fertilizer system

Oats use 25-29 kg of nitrogen, 7-14 kg of phosphorus, and 18-33 kg of potassium to form 1 ton of grain and the corresponding amount of straw.

Organic and mineral, especially nitrogen, fertilizers give good results when applied to oats. It uses the aftereffect of manure and compost, giving a yield increase of more than 0.4 t/ha. When sowing oats on newly developed lands or when overseeding clover, nitrogen and phosphorus-potassium fertilizers are applied, which increase the yield of oats and promote clover growth.

On old-cultivated soils is effective full mineral fertilizers. Good gains are obtained from the introduction of phosphate fertilizers in granular form. In experiments, the plant laboratory of the Moscow Agricultural Academy, introducing granular superphosphate increased yield by 0.35 t / ha compared with simple superphosphate in the same amounts. Even greater effect is obtained when applying granulated superphosphate in rows at a dose of 10-50 kg/ha.

Table. Efficiency of fertilizers for oats on different soils (All-Russian Institute of Fertilizers and Agrosoil Science)

Soils
Yield without fertilizer application, 100 kg/ha
Yield increase at application, 100 kg/ha
NK
NP
PK
NPK
Podzolic sandy loam
10,8
4,9
5,6
1,4
8,4
Podzolic loamy
12,3
4,1
5,4
2,6
7,6
Grey forests
14,8
5,8
6,6
1,0
7,5
Podsoled and leached black soils
16,3
5,1
7,4
1,5
9,1
Strong and common black soils
18,8
3,1
4,7
2,3
5,5

It follows from the above data that oats are responsive primarily to nitrogen fertilizers on all types of soils. In the Non-Black Soil Zone it makes good use of the aftereffect of manure, in the Black Soil Zone – full mineral fertilizer.

Potassium consumption during the growing season is approximately uniform. Maximum consumption of nitrogen is in phases of tillering – emergence of a tube, phosphorus – the initial periods of growth.

Fertilizer rates are set with regard to the content of nutrients in the soil, utilization rates and planned yields. Approximate rates of mineral fertilizers for oats are N40-60P60-90K50-60.

When growing on drained peatlands, copper microfertilizers are of great importance. According to the experiments of the Institute of Soil Science and Agriculture of the Latvian Academy of Sciences (Latvian SSR), the application of pyrite pellets on sod-gley soils of coastal regions increased the yield of oat grain by 0.4-0.9 t/ha.

When using the calculated methods of determining the norms of fertilizers, then at the expense of nitrogen to obtain 1 ton of grain 25-26 kg for the Non-Black Earth zone sets the correction factor of 0.6, for other regions 0.7-0.8. With a high content of mobile phosphorus and exchangeable potassium correction factors are 0.5 and 0.6, respectively.

Phosphorus-potassium fertilizers are applied in autumn under the main tillage, or in spring simultaneously with nitrogen fertilizers for pre-sowing tillage.

Nitrogen fertilizers are also applied in the phase of emergence of the tube in the amount of N40 taking into account the results of plant diagnostics.

Tillage system

Oats, like other cereal crops, also respond to early autumn tillage. According to the Voronezh Agricultural Institute, early autumn tillage increases oat yield by 0.3 t/ha compared with late autumn tillage.

When oats are placed after row crops that have been properly tended, autumn tillage is not necessary. During the winter period, the soil after potatoes is usually heavily compacted, so in spring the tillage begins with deep cultivation with simultaneous harrowing.

In areas with insufficient moisture, snow retention, and melt water retention are carried out in spring. For this purpose, when snow melts, snow ramparts across the slope are arranged.

In the Non-Black Soil Zone on heavy soils perform deep to 10-12 cm deep pre-sowing loosening by cultivators, in some cases more appropriate spring re-plowing with plows with moldboards removed to a depth of 12-16 cm with simultaneous harrowing.

In order to carry out sowing in optimal time, pre-sowing processing is carried out in a short time. Rolling after deep loosening contributes to reduction of moisture loss by evaporation and levels the soil surface. The roller is followed by light harrowing.

Sowing

Seed preparation

The peculiarity of preparation of oat seeds for sowing is their division into two groups of grains, which differ from each other in shape and coarseness. The first, lower grains in the spike are heavier, formed earlier and mature better. The second, upper grains, are smaller. The first kernels make the plants grow more vigorous, bushier, and produce a larger yield. To separate the upper grains, conventional oat separators (triers) or more complex ОС-4.5A machines are used.

For sowing, it is recommended to use seeds with a mass of 1000 pieces of 30-35 g and a growth force of at least 80%.

To increase the germination energy and germination of seeds, especially in areas of Siberia, the Urals and the Non-Black Earth zone, in which during the ripening and harvesting is wet weather, seeds are subjected to air-heat treatment. In cold and wet spring heating is carried out in grain dryers at 35-40 °C.

Before sowing, seeds of oat plants are etched with 0.38 L. formalin in a 40% aqueous solution not earlier than 3-5 days before sowing.

Adhesive agents, e.g. NaKMC, are used to increase treatment efficiency.

Microfertilizer treatment also belongs to pre-sowing treatment of oat seeds. Consumption rates: boron – 100 g/t seed, zinc – 120 g/t seed, manganese – 180 g/t seed, copper – 300 g/t seed.

For seed dressing against diseases are used:

  • dusty smut – Divided Star (30 g/l diphenoconazole + 6.3 g/l ciproconazole), Agat-25K (titer 50-80 bln before inactivation), Premis Two hundred (200 g/l triticonazole), Vincit Forte (37.5 g/l flutriafol + 25 g/l tiabevdazole + 15 g/l flutriafol);
  • covered smut – Premis Two hundred (200 g/l triticonazole), Vincit Forte (37.5 g/l flutriafol + 25 g/l thiabedazole + 15 g/l flutriafol);
    hard (stone) smut – Colfugo Duplet (200 g/l carbendazim + 170 g/l carboxin), Agat-25K (titer 50-80 bln before inactivation);
  • stem smut – Colfugo Duplet (200 g/l carbendazim + 170 g/l carboxin);
  • Helminthosporiosis root rot – Agat-25K (titer 50-80 bln before inactivation);
  • Fusarium root rot – Colfugo Duplet (200 g/l carbendazim + 170 g/l carboxin), Agat-25K (titer 50-80 bln before inactivation);
  • seed mold – Dividend Star (30 g/l diphenoconazole + 6.3 g/l ciproconazole), Premis Two hundred (200 g/l triticonazole), Vitaros (198 g/kg carboxin + 198 g/l tiram);
  • root rot – Colfugo Duplet (200 g/l carbendazim + 170 g/l carboxin);
  • red-brown spot – Divide Star (30 g/l diphenoconazole + 6.3 g/l ciproconazole).

Timing of sowing

The earliest sowing dates are optimal when the soil reaches physical ripeness. However, some delay in sowing does not lead to such a sharp decrease in yields as in spring wheat and barley. This can be explained by comparatively light adaptability of oats to environmental conditions, quick formation of secondary roots, and less damage by Swedish and Hessian flies.

Early crops are significantly less affected by rust, especially in humid areas, but they do not give the best results everywhere. In Eastern Siberia, in the steppe and forest-steppe regions of Western Siberia, Trans-Ural and northern Kazakhstan, the earliest sowing dates often lead to “pupal formation” (viral disease). Diseased plants strongly bushy and hardly form panicles; the disease is particularly strong in the wet summer. The disease vector is the dark cicada.

In addition, sowing oats in the Urals and Western Siberia in the end of May makes better use of summer precipitation.

Therefore, one of the agrotechnical methods of struggle against “pupae formation” is medium sowing terms, i.e. in the second half of May, and also sowing of healthy seeds with high germination energy; greater density of sowing by using narrow-row or cross-sowing method; introduction of physiologically acidic forms of phosphorus fertilizers; refusal of repeated sowing.

Sowing methods

Narrow-row and cross-sowing methods of oats are optimal. The rate of sowing in these methods is increased by 10-20% compared with the usual. Also conventional row sowing is used, which allows to leave technological tracks for maintenance of crops.

Seeding rates

Recommended seeding rates for oats:

  • Non-Black Soil Zone – 5.5-7 million/ha of germinating seeds;
  • Central Black Earth zone – 4.5-5.5 million/ha of germinating seeds;
  • Southeast Russia – 3.5-4.0 mln/ha of germinating seeds or 110-130 kg/ha;
  • Eastern Siberia – 6-7 mln/ha of germinating seeds;
  • Siberia and the Far East – 5.5-6.5 million/ha of germinating seeds or 160-200 kg/ha;
  • North Caucasus and Ukraine – 4.0-5.5 million/ha of germinating seeds or 130-170 kg/ha.

The recommended rates are adjusted depending on moisture (in dry conditions it is reduced), soil weediness, methods of seeding. Seeding rate can be reduced if the fields are sufficiently fertilized.

Sowing depth

The depth of oat seeds sowing depends on the region of cultivation, the nature of soil and the timing of sowing. In the northern regions on heavy soils it does not exceed 3 cm, on drained bogs – 2-3 cm. In semi-arid areas on chernozem soils – 4-5 cm, with a strong drying of the upper layer of soil – 5-6 cm.

Crop care

In case of moisture deficiency in the upper soil layers, post-sowing rolling is effective. At the Tambov Agricultural Experimental Station, rolling with ring rollers increased the oat yield by 0.15 t/ha on average over 5 years.

On heavy soils and wet spring, pre-early harrowing with needle or tooth harrows when the root length does not exceed the length of the grain. Harrowing allows you to break the soil crust and loosens the soil, which contributes to better aeration of the upper root layer and creates favorable conditions for the emergence of uniform sprouts. Harrow the shoots only after a good establishment of plants in the tillering phase with light, medium harrows or rotary hoes. Pre- and post-emergent harrowing in the tillering phase is an effective agrotechnical method of weed control.

In the fields of the Crop Husbandry Laboratory of the Moscow Agricultural Academy, one-track harrowing in the tillering phase increased the oat yield from 3.33 to 3.82 t/ha in three years on the average. At the same time weed infestation was reduced by 12%. Soil moisture after harrowing was 2-2.5% higher than on the untreated ones.

Harrowing across the rows in the phase of tillering promotes better plant development, increases productive bushiness and the number of spikelets in the panicle.

With low weed infestation preference is given to agrotechnical methods of weed control. When the infestation of thistles is more than 2 plants per 1 m2 or 15 plants of other weeds per 1 m2 use herbicides.

Characteristic diseases of oat include dusty smut, crown rust, red-brown spot, and root rot.

Characteristic pests of oats are Swedish fly, stem fleas, baker’s weevil, grain aphids, oat thrips.

Plant protection system

Alto (400 g/l cyproconazole) is used to control brown rust, powdery mildew, rhynchosporiosis and helminthosporiosis spots. Bayleton (250 g/kg) and Tilt (250 g/l propiconazole) are used against crown rust and red-brown spot.

Harvesting

Ripening of oats proceeds unevenly, above all in the case of strong pre-ripening. Grain ripening in spikelets occurs earlier in the upper part of the panicle. Ripening in the lower tiers is considerably delayed. Oats, unlike wheat and barley, do not ripen well in windrows, so if they are harvested too early, a lot of green grain is produced.

Two-phase or one-phase harvesting of oats begins at the end of wax ripeness of the grain of the upper part of panicles, where the largest grains are located. Harvesting in the phase of full ripeness leads to large losses of large grains.

On clean fields and with uniform maturity, harvesting is carried out in a one-phase method.

Sources

Crop production/P.P. Vavilov, V.V. Gritsenko, V.S. Kuznetsov, et al. Gritsenko, V.S. Kuznetsov, etc.; Edited by P.P. Vavilov. – M.: Agropromizdat, 1986. – 512 p.: ill. – (Textbook and textbooks for higher education institutions).

V.V. Kolomeychenko. Horticulture/Textbook. – Moscow: Agrobiznesentr, 2007. – 600 с. ISBN 978-5-902792-11-6.

Fundamentals of agricultural production technology. Farming and plant growing. Ed. by V.S. Niklyaev. – Moscow: “Bylina”. 2000. – 555 с.