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AGROTECHNOLOGY FOR GROWING SPRING CROPS ON RAINFED LANDS OF UZBEKISTAN.
Bekmurad Haydarov,
Director of Research Institute of Rainfed Agriculture,
PhD of agricultural science. Mamatkul Juraev, Chief of laboratory, PhD of agricultural science.
The effects of global warming on the natural and climatic conditions of the agricultural regions of the republic are being felt. The negative impact of climate has a negative impact on the food security of the population living in rainfed areas.
The total sown area of agricultural crops in the country is 3998.5 thousand hectares, of that arable land - 759.7 thousand hectares. (National Report on the State of the Lands of the Republic of Uzbekistan, Davergeodezcadastre, 2020).
All arable lands of rainfed areas in the country divides into 4 zones according to altitude, soil and weather conditions:
1. Plain flat region. This region is not provided with precipitation and the annual rainfall is 250300 mm. Strong weather and soil drought occur in the region in spring and summer.
2.The hill step regions. Annual precipitin in this area is 300-350 mm.
3.Foothill region. The annual rainfall in this region is 400-450 mm.
4. Mountainous region. Annual precipitation in this region of rainfed areas is 450-500 mm and more.
Currently, global climate change, including global warming is observed to significantly affect the yield of grain and other crops on dry lands. According to the Republican Hydrometeorological Center in over the past decades the weather has been above the average perennial air temperature of + 1,5 + 20C.
Under the influence of global warming the recurrence of drought has accelerated while until 2010 the years of severe drought were repeated every 8-10 years in subsequent years. We can see that this process has accelerated to 4-5 years.
On the rainfed lands of the country in 2021 during the sowing of winter cereals there was a sharp decrease in soil moisture. Under such conditions the cultivation of dry lands and the implementation of quality planting work requires additional agrotechnology.
In the autumn it was not possible to cultivate the land in the dry lands of the republic. Only on farms where crop rotation was established the seeds of autumn grain were sown in late October
and November. However, it was observed that grain seeds in such areas did not germinate fully in December and January.
It is known that the yield of winter cereals, legumes and other crops in arable lands depends in many respects on the amount of precipitation in winter and early spring and the depth of soil moisture.
To date, the amount of precipitation in arable lands is 92 mm less than the perennial norm (average perennial precipitation up to the first ten days of February is 142 mm), the depth of soil moisture is 25-30 cm in stem lands (not fallow), 4045 cm in clQan fallowing. Under such conditions, it will be possible to sow grain and legumes and oilseed7 n dry lands.
In years of low humidity in dry lands, the n muer of crops per 1 m2 of cereals is important. A ccording to many years of experience, the optimal number of crops per 1 m2 of cereals is 100-110 in the plains, 120-130 in the hill-steps, 140-150 in the foothills and 160-180 in the mountains.
Additional planting is required when the number of crops per 1 m2 of cereals is 40-50 in the plain lands of rainfed areas, 60-70 in the hill-steps and 80-90 in the foothills and mountainous areas. In this case, it is recommended to sow varieties of biological spring bread wheat Surkhak-5688, Okbugday, Bakhmal-97, Nushkent, barley Unumili arpa, Savruk, Abu Ghafur at the rate of 40-50 kg/ha.
It is recommended to replant if the number of crops per 1 m2 of cereals in is 30-40 in the plains, 40-50 in the hill-steps and 50-60 in the foothills and mountainous areas. One of the most important things to do immediately in the early spring months is to feed the cereals fields. In this year's weather conditions, it is not recommended to feed winter cereals.
Due to the possibility of the spread of weeds, diseases and pests in the spring of this year in the control to weeds, keeping the soil moisture is important. In this case, the needed treatment is carried out with the help of harrows cereals fields. This should be held with the feeding. The storm is effective only during the flowering period of the plant, when the number of plants per 1 m2 exceeds
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the norm.
Spring cereal crops. Decrease in precipitation during flowering and grain filling, which is the most responsible stage of vegetation of these crops, the occurrence of air drought as a result of a sharp rise in air temperature has a negative impact on the accumulation of organic matter, i.e. photosynthetic activity of plants.
In dry lands, the areas sown with spring cereals are plowed in the fall or on clear and warm days of winter, turning the soil to a depth of 20-22 cm. In the plains, where there is no precipitation, the optimal time for sowing the seeds of cereals is the end of February, the first ten days of March. Before planting in this area, the plow is treated on the soil surface with heavy harrows toothed in two directions. The use of organic and mineral fertilizers is not recommended in the cultivation of cereals in this region, which is poorly supplied with precipitation.
Recent experiments and observations show that in some years, when the rainfall in these plains is 280-300 mm and the depth of soil moisture is 1 m, nitrogen fertilizers are applied to 20-30 kg/ha (in terms of pure active substance) of spring crops. The norm of sowing of spring bread wheat and barley seeds in this plain region is 2.5-3.0 millvn seeds per hectare or 100-110 kg/ha. In this region it is advisable to plant spring or facultative varieties of bread wheat and barley.
In the hill-step (340-360 mm) region, which accounts for more than 60% of the total arable land in the country. The soil is plowed to a depth of 2022 cm on open days in autumn and winter, as in the plain region for early spring sowing of cereals. Before sowing it is processed in both directions using heavy harrows. Top dressing of 30-40 kg/ ha of pure phosphorus and potassium fertilizers before sowing in this area or the same amount of nitrogen fertilizers during tillage will increase the average yield by 3 times. 5 t/ha.
In the foothills and mountainous regions of the country if all agrotechnological measures are carried out in a timely and quality, it will be possible to grow grain yield on average 12-15 t/ ha and in the more precipitation years 15-18 t/ ha. This requires quality tillage of the soil, feeding it with pure nitrogen, phosphorus and potassium fertilizers at the rate of 40-50 kg/ha.
In the foothills and mountainous areas, the best time to sow spring wheat varieties "Surkhak-5688", "Bakhmal-97", "Grekum-40" is the second and third decade of March. The optimal sowing norm is 3-3.5 million seeds per ha (120-130 kg/ha).
The arrival of the spring months, high humidity, severe damage of wheat sown in autumn
and spring by rust and other diseases are observed not only in irrigated but also in arable lands. Therefore, the planting of rust-resistant varieties in rainfed lands, as well as treatment with fungicides, if necessary, gives effective results.
To prevent contamination of grain crops with smuts and powdery mildew diseases, it is necessary to pre-sow the seeds with quality treatment with recommended fungicides.
Legumes. One of the legumes, which has the property of accumulating nitrogen in the soil is a chickpea, which is planted in the early spring in a busy plowing scheme in grain-plowing crop rotation schemes. This plant has long been planted in rainfed lands due to its high resistance to drought.
At present, the Research Institute of Rainfed Agriculture has developed high-yielding, disease and pest resistant varieties of chickpeas, such as Lazzat, Jahongir, Uzbekistan-32, Yulduz, Gulistan, Zabardast and Iftixor.
In the hill-step region of rainfed lands, the optima' mowing period of chickpeas is the second decade of March, the sowing rate is 60-70 kg per hectare, and in the foothills and mountainous areas the end of March, the first decade of April. In these regions, the sowing rate of chickpeas is 75-80 kg/ ha. In determining the sowing rate, the weight of ^0^0 grains is taken into account, in large-grain chickpeas varieties the sowing rate is higher. Row spacing is 45-60 cm, it is depending on soil moisture.
Chickpeas is a plant demanding to soil fertility and high agrotechnics. Therefore, in the autumn plowed fields should be plowed and mulched before planting. This work needs to be done in the short term to reduce evaporation of soil moisture. In dry lands, the pea plant is demanding to phosphorus fertilizers. In order to meet the need of nitrogen compounds in the early stages of growth and development of chickpeas. It is advisable to apply nitrogen-containing phosphorus fertilizers (ammophos, AFU, etc.) before or in combination with 30-40 kg/ha of pure active substance. During the growing season, loosening between rows and weeding during the 3-5 leaf and combing stages leads to an increase in yield.
One of the main diseases of the chickpeas plant in rainfed lands is Ascochyta. The disease is most common in the years when the spring months are cool and rainy leading to a decrease in yield and even complete losses of the plant. Sulfur spraying or working with fungicides against this disease gives good results.
Growing oilseeds. One of the oilseeds grown in the arable lands of the republic is Saflor. The Saflor plant has a strongly developed arrow root, penetrates up to 1,5-2 m layer of soil and makes full use of moisture reserves in its lower layers.
Therefore, this crop is a highly resistant plant to drought.
The oil content of saflor grain is 25-35%. Depending on the soil and weather conditions, as well as the level of agricultural technology, its height ranges from 40-50 cm to 100-120 cm. Its seeds begin to germinate when the soil temperature is +1+20C. In the plain arable lands of Tashkent, Jizzakh, Samarkand and Navoi regions.The best time to sow is the first ten days of March and in the foothills the last ten days of March and the first ten days of April. In the southern regions, s saflor can also be planted on clear and warm days of winter.
In arable lands, like other oilseeds, saflor is planted on a busy plow in a grain crop rotation scheme. Field crops are plowed in autumn with plows to a depth of 20-22 cm. Before planting, using shallow or harrows, a shallow furrow is made at a depth of 5-8 cm and the mulch is pressed. The sowing norm is 20-22 kg/ha at 30 cm row spacing, 15-18 kg/ha at 45 cm row spacing and 4-5 cm depending on soil moisture.
Milyutin-114, Gallaorol and Jizzakh-1 varieties of saflor are recommended for sowing on rainfed lands. The purity of seeds prepared for sowing should be 95%, germination in the laboratory should not be less than 85% and the weight of 1000 grains should be 45-50 g.
In the arable lands of the republic, the most common pests that cause severe damage to the saflor plant are the small and large long-nosed, saflor mosquitoes. These pests overwinter mainly in the bark of sheltered trees inside the stems of saflor, long-nosed and flies feed on flowers and seeds in baskets from the first half of May and damage the baskets.
Biological control of pests and the use of chemicals are effective. It uses 500 xrabrakon and goldfish per hectare, as well as 20-30 kg of sulfur powder per hectare, sulfur-lime decoction, Sumi-alpha 0,2-0,3 l/ha, Tsiperfos 5,0 l/ha.
Growing oily flax. Flax is one of the most important oilseeds grown in the arable lands of the republic. Its seeds contain 30% to 50% of valuable oil and the level of oil yield varies depending on soil and weather conditions, as well as agrotechnology. Flaxseed oil is used in the food industry, as well as in the manufacture of paints, varnishes, linoleum, film, and the stem is used in the production of quality paper and rough materials.
Flax root is an arrow root that effectively uses moisture from the deeper layers of soil on dry and hot summer days. Plant length varies from 20 cm to 70 cm, depending on the variety and soil-climatic conditions. Flax is more demanding on soil fertility than maize, and yields and oil yields are reduced in soils that are heavy, dense and lack nutrients. Like
other crops planted in the busy field flax fields need to be plowed to a depth of 20-22 cm in the fall and quality tillage is required before planting.
The best time to plant flax in dry lands is the first half of March in the plains, hill-step areas, the end of March and the first ten days of April in the foothills and mountainous areas. The sowing rate should be 16-18 kg/ha in the lower arable land, 20-22 kg/ha in the mountainous areas and the planting depth should be 4-6 cm depending on the soil moisture.
In Rannik stadiums, flax grows very slowly and is replaced by weeds. Therefore, it is desirable to plant flax in areas free from weeds. As soon as the seeds ripen and turn brown, the crop should be immediately harvested using combine harvesters.
Growing sesame seeds. Sesame is one of the most valuable oilseeds grown in the arable lands of the republic since ancient times. The oil content of its seeds is 55-60% and ranks first among oilseeds.
Sesame oil is widely used in the food and confectioner' industry, as well as in medicine, due to its richness in protein, carbohydrates and essential amino acids.
Sesamt root is a bullet root and absorbs moisture and mineral nutrients well in 1.5-2 m layer of soil. This crop is very demanding on soil fertility and structure that requires the use of high agro-technologies. The density and porosity of the soil in which sesame is planted should be around the norm, free from weeds. A busy plow planted with sesame is plowed in early spring with plows to a depth of 20-22 cm. In late April, the first ten days of May, after the cessation of rains, it is required to work with flat plows (ploskorez) or chisel-cultivators to a depth of 12-15 cm and immediately plow in both directions.
In this case, the evaporation of moisture from the soil decreases sharply. Before or in conjunction with sesame seeds are applied nitrogen-containing phosphorus fertilizers at the rate of 30-40 kg/ha, depending on soil fertility and the type of previous crop.
The optimal time for sowing sesame seeds is the last ten days of April the first ten days of May in the hill step lands. The second ten days of May in the foothills and mountainous regions. The sowing rate should not exceed 3-4 kg per hectare and the depth should not exceed 2,5-3 cm.
Sesame seeds begin to germinate at a temperature of +14 +150C and at +16+180C fully germinate. Since sesame seeds are very shed after ripening, the crop is harvested by hand.
Agro technology of forage crops. Many years of experience have shown that the planting of perennial and annual legumes (alfalfa, peas, etc.) plays an important role in ensuring a stable positive
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balance of organic matter (humusj in the soil and improving its water-physical and other properties in arable lands where soil fertility is deeply degraded lands.
Aridnaya and Boygul varieties of alfalfa are grown for 7-8 years in the humid foothills and rainfed foothills of dry lands. In mountainous areas where the soil is strongly affected by water erosion, alfalfa is grown directly on a grain-alfalfa rotation scheme.
Perennial alfalfa fields are plowed in autumn to a depth of 20-22 cm. In early spring, in the first days of March the field is worked diagonally using disc harrows, chisel cultivators (ChKU-4) can also be used instead of disc harrows (LDG-10).
The period of planting alfalfa in the plains, hill steps of rainfed lands is March, the first ten days of April in the foothills and mountainous areas. The sowing rate is 10-12 kg / ha in the lower region and 14-16 kg / ha in the foothills and mountainous areas to obtain blue mass. In the cultivation of alfalfa
seeds are sown in wide rows (30-45 cm) at the rate of 8-10 kg / ha. In all arable areas, alfalfa seeds should be sown in 1.5-2 cm layer of soil using grain drills equipped with anchor plows (SZT-3.6, DEM-3.6). As mentioned above, alfalfa, like all legumes is demanding to phosphorus fertilizers. In the plains and hills that phosphorus fertilizers should be applied under autumn plowing at the rate of 30-40 kg/ha and in the foothills and mountainous areas at the rate of 50-60 kg/ha.
In early spring, alfalfa seeds are sown at a rate of 10-12 kg/ha and immediately treated with light storms. One of the insects that reduces alfalfa blue mass and seed yield in dryland areas is phytonumus. One of the agro-technical and chemical control measures against this pest is the treatment of alfalfa fields in the early spring with the help of milling or disc harrows and application of 25% Cypermethrin (SP-ZAO, Uzbekistan) at the rate of 0,2-0,3 l/ha and other insecticides before flowering gives good results.
