The article presents the data of assessing the productivity and nutritional value of selection samples of creeping clover in the nursery of the competitive variety testing of 2016 sowing for three years of use. The purpose of the research is to identify a promising breeding material of creeping clover for creating a variety with high productivity of green mass and seeds, suitable for mechanized harvesting of seeds for the conditions of the forest-steppe of the Middle Volga region. The research was carried out in 2017-2019 on the experimental field of a separate subdivision of Penza FGBSI FSC of BC in accordance with the methodological instructions for the selection of perennial grasses. On average over three years of use in terms of the yield of green mass – 15.00-16.44 t/ha, cultivar samples of creeping clover V-92, Yu-90, P-97, Pl-90-4 significantly exceeded the VIK-70 standard (14,01 t/ha) by 7.1-17.3%, for the collection of dry matter – 3.49-3.97 t/ha varieties V-92, Yu-90, P-97 and Pl-90-3 reliably exceeded the standard (3.29 t/ha) by 6.1-20.7%, in the collection of digestible protein – 0.44-0.49 t/ha, the varieties B-92 and P-97 exceeded the standard (0, 40 t/ha) by 10.0-22.5%. Maximum values of the yield of green mass (16.44 t/ha), dry matter collection (3.97 t/ha), digestible protein (0.49 t/ha), feed units (5.04 t/ha) and exchange energy (49.12 GJ/ha) on average for the years of testing showed the sample P-97. This specimen significantly exceeded the standard in terms of structural elements and seed yield by 50.5%, in the height of leaf petioles by 3.5% and peduncles by 2.5%, which is important for mechanized harvesting of seeds. When selecting for the productivity of creeping clover, one should pay attention to the signs associated with the yield of green mass and seeds. The length of leaf petioles correlates with the length of peduncles (r = 0.78), the number of seeds in the head (r = 0.46), the number of inflorescences in the head (r = 0.47), with the collection of dry matter (r = 0.31). The length of the peduncles correlates with the collection of dry matter (r = 0.30), with the number of inflorescences in the head (r = 0.54), and with the number of seeds in the head (r = 0.51). The number of inflorescences in the head correlates with the number of seeds in the head (r = 0.61) and with the yield of seeds (r = 0.31)

Селекционную работу с люцерной изменчивой (Medicago × varia Mart.) проводили в 2019–2022 годах на полях лаборатории агротехнологии ФНЦ ЛК ОП «Пензенский НИИСХ». Цель исследований — изучить и выделить по комплексу хозяйственно ценных признаков образцы люцерны в смеси со злаковым компонентом (кострецом безостым), перспективные для возделывания в лесостепной зоне Поволжья, адаптированные к местным агроклиматическим условиям и обеспечивающие 8–10 т/га сухого вещества при сенокосном использовании. Наиболее благоприятными для возделывания люцерны со злаковым компонентом на корм были первый и третий годы использования (2020 и 2022 годы; ГТК — 0,8 и 1,1 соответственно). Сбор сухого вещества в среднем по питомнику в эти годы составил 12,75 и 9,29 т/га соответственно. За 3 года использования выделены перспективные сортообразцы с высокой кормовой продуктивностью. Сортообразец № 2 (Урожайная 3) сине-пёстро-гибридного сортотипа, характеризовался отличной общей оценкой по архитектонике и отрастанию, облиственность — 54,5% (+10,0% к стандарту), доля люцерны в травосмеси — 69,0%; сбор сухого вещества составил 10,44 т/га (+17,3% к стандарту), выход переваримого протеина — 0,98 т/га (+8,0% к стандарту), обменной энергии — 98 ГДж/га (+14,7% к стандарту); слабо поражался пятнистостями и микоплазмозом. Сортообразец № 5 (ВИК № 27) пёстро-гибридного сортотипа, отличался хорошей архитектоникой и отрастанием; облиственность — 58,6% (+13,3% к стандарту); сбор сухого вещества составил 10,24 т/га (+15,0% к стандарту), выход обменной энергии — 96 ГДж/га (+12,9% к стандарту), содержание переваримого протеина в 1 корм. ед. — 180 г (+11,8% к стандарту); слабо поражался болезнями. В настоящее время сортообразцы № 2 (Урожайная 3) и № 5 (ВИК № 27) находятся в предварительном размножении для дальнейшей передачи лучшего из них на ГСИ The breeding project on bastard alfalfa (Medicago × varia Mart.) was carried out at the Laboratory of Agricultural Technology of the Penza Agricultural Research Institute in 2019–2022. Its aim was to analyze and select valuable genotypes of bastard alfalfa grown with smooth brome to be cultivated in the forest-steppe of the Volga region, resistant to local environment and producing 8–10 t ha-1 of dry matter (DM) under hay production. The growing seasons of 2020 and 2022 were the most favorable for alfalfa cultivated with the gramineous component (the hydrothermal coefficients — 0.8 and 1.1, respectively). The DM yield amounted to 12.75 and 9.29 t ha-1 in these years, respectively. For 3 years promising genotypes were selected showing high forage productivity. The genotype No. 2 (“Urozhaynaya 3”) of the blue-particolored-hybrid type showed excellent architectonics and regrowth, leaf coverage — 54.5% (+10.0% versus a standard), alfalfa proportion in the mixture — 69.0%. DM yield amounted to 10.44 t ha-1 (+17.3%), the production of digestible protein — 0.98 t ha-1 (+8.0%), exchange energy — 98 GJ ha-1 (+14.7%). The genotype had good resistance to the blight diseases and mycoplasmosis. The genotype No. 5 (“VIK No. 27”) of the particolored-hybrid type, had good architectonics and regrowth; leaf coverage — 58.6% (+13.3%). DM yield amounted to 10.24 t ha-1 (+15.0%), exchange energy — 96 GJ ha-1 (+12.9%), the content of digestible protein in 1 feed unit — 180 g (+11.8%). The genotype showed good resistance to diseases. Currently the genotypes No. 2 (“Urozhaynaya 3”) and No. 5 (“VIK No. 27”) are undergoing the preliminary multiplication to be sent for the State Variety Trial

The development of technology elements for the cultivation of perennial alfalfa-brome mixtures contributes to the formation of highly productive agrocenoses and reduce the cost of fodder mass. In 2017-2022, in the conditions of the Penza region, there has been studied the effect of seeding rates of alfalfa variegated of Daria variety and awnless brome Udalets in pure and mixed sowings, the level of mineral nutrition and the time of harvesting green mass on the economic and energy efficiency of cultivation. Growing seasons of 2017-2021 were characterized by dry conditions (HTC = 0.4-0.8), of 2022 – by normal moisture (HTC = 1.0). The calculation of the cost of production showed the advantage of the seeding rate of alfalfa and brome 70+40 %, the introduction of N45P60K90 and harvesting in the early phase the cost of 1 ton of feed units amounted to 2.36 thousand rubles, in the variant without fertilizers at this seeding rate, the cost was 6.8 % higher – 2.52 thousand rubles. The level of profitability of alfalfa-brome mixtures when cultivated for green mass was at a high level and amounted to 161-238 % according to the variants. Higher rates were obtained in variants with a seeding rate of 70+40 %, the introduction of N45P60K90 during harvesting both in the budding phase and variable mowing – 235-238 %. Cost of 1 ton feed units at a seeding rate of 70+40 % was 1.51-1.96 GJ (depending on the mowing period), a decrease in the seeding rate of alfalfa to 40 % increased the cost of 1 ton of feed units up to 1.74-2.20 GJ. The use of mineral fertilizers increased the cost of 1 ton of feed units when applying P60K90 by 0.02-0.06 GJ, and when introducing N45P60K90 by 0.29-0.36 GJ. The early phase of harvesting was energetically favorable – the cost of 1 ton of feed units was lower than when harvesting in the flowering phase by 0.08-0.15 GJ. With a high seeding rate of alfalfa and a low seeding rate of brome (70+40 %), the maximum energy efficiency coefficient (EEC) was obtained – 5.2-7.1 (depending on the background of nutrition and the mowing period). With a decrease in the seeding rate of alfalfa from 70 to 40 %, a decrease in the EEC to 4.5-6.1 was noted. The application of mineral fertilizers significantly reduced the EEE indicators – from 5.8-7.1 to 5.5-6.7 with the application of P60K90 and to 4.3-5.3 with the application of N45P60K90. At an early harvesting time (budding phase), the EEC was slightly higher – 4.7-7.1, than at a late harvesting time (flowering phase) – 4.5-6.8.

В связи с широким ареалом возделывания люцерны и повышения эффективности её использования в современном сельском хозяйстве необходимо внедрять сорта нового поколения, обладающие широкой амплитудой устойчивости к абиотическим стрессовым факторам. Разработка приемов возделывания люцерны изменчивой сорта Дарья предусматривает использование резервов фотосинтетической деятельности для повышения её продуктивности. Поэтому целью исследований является определение оптимального срока посева люцерны изменчивой, при котором формируются высокие урожаи за счет лучшего использования фотосинтетической функции растений. Эксперимент проводили на опытном поле Пензенского ИСХ филиала ФГБНУ Федеральный центр лубяных культур в 2017-2019 гг. на черноземе выщелоченном, где изучали четыре срока посева: первый ранневесенний (1-10 мая), совпадающий с физической спелостью почвы второй - поздневесенний (20-30 мая) и два срока посева, проведенные в летний период: 1-10 июня, последующий с интервалом в 30 дней к предыдущему. Годы исследований характеризовались как сухие и засушливые. Наиболее оптимальные условия для развития ассимиляционной поверхности растений первого года жизни складывались на ранневесенних посевах, где площадь листьев была наибольшей 30,5 тыс. м2/га. По мере сокращения вегетационного периода наблюдается снижение индекса листовой поверхности в 1,5 раза. Наиболее интенсивное формирование ассимиляционной поверхности происходило в 2017 году и ее площадь составила 35,819,7 тыс. м2/га, максимума она достигала при раннем посеве. В этом же году отмечена наибольшая величина фотосинтетического потенциала 10012638 тыс. м2 сутки/га. В среднем за три года максимальный 2129,3 тыс. м2сутки/га он формировался у растений при посеве ранней весной, а чистая продуктивность фотосинтеза находилась в диапазоне от 0,87 до 0,93 г/м2 сутки. Наибольший показатель установлен при ранних посевах, что способствовало накоплению 2,0 т/га сухого вещества.Due to the wide range of cultivation of alfalfa and increasing the efficiency of its use in modern agriculture, it is necessary to introduce varieties of a new generation with a wide amplitude of resistance to abiotic stress factors. The development of methods for cultivating variegated alfalfa of the Dariya variety involves the use of reserves of photosynthetic activity to increase its productivity. Therefore, the aim of the research was to determine the optimal sowing period for variagated alfalfa, at which high yields could be formed due to the better use of the photosynthetic function of plants. The experiment was conducted on the experimental field of Penza Agricultural Institute - a branch of the Federal Center for Bast Crops in 2017-2019. The soil was leached chernozem (black soil). Four sowing periods were studied: the first - early spring (May, 1-10), coinciding with the physical ripeness of the soil the second - late spring (May, 20-30) the other two were carried out in the summer period: the third - June, 1-10 and the fourth - in 30 days after the previous one. The years of the research were characterized as dry. The most optimal conditions for the development of the assimilation surface of plants of the first year of life were formed in early spring crops, where the leaf area was the largest - 30.5 thousand m2/ha. As the growing season decreased, a 1.5 times decrease in the leaf surface index was observed. The most intensive formation of the assimilation surface took place in 2017 and its area was 35.8...19.7 thousand m2/ha, reaching its maximum during early sowing. In the same year, the highest value of photosynthetic potential of 1001...2638 thousand m2 day/ha was noted. On average, over three years, the maximum potential of 2129.3 thousand m2day/ha was formed in plants during sowing in early spring, and the net productivity of photosynthesis was in the range from 0.87 to 0.93 g/m2 day. The highest index was established during early sowing, which contributed to the accumulation of 2.0 t/ha of dry matter.

Undercrop cultivation of alfalfa is economically justified, since in the year of sowing, cover crops give a full harvest, and also one mowing of alfalfa for hay is carried out, moreover the special preparation of the soil for grasses is not re-quired. In the conditions of the Middle Volga region, the experiment was laid on leached chernozem in 2017 - 2019, where they studied the sowing of variegated alfalfa under the crops of spring wheat, barley, oats, harvested for grain and an-nual grasses - for green fodder, and studied the options for coverless sowing, where the weeds were mowed twice and the herbicide Pivot was applied at the beginning of alfalfa branching. The total biological yield is determined by the leaf area and its photosynthetic activity. Therefore, the purpose of the research is to determine the indicators of alfalfa photosynthetic activity for an objective as-sessment of the influence of cover crops on their forage productivity. It has been established that a more intensive increase in the assimilation surface of alfalfa in the first year of life to 31.6 and 30.6 thousand m2 /ha occurs on coverless sowing with the application of the Pivot herbicide and two-fold mowing of weeds. The dry matter yield was 2.1 and 2.0 t/ha, respectively. A decrease in the illumination of alfalfa plants sown under crops, where the leaf area did not exceed 13.0...15.3 thousand ? m2 / ha, slowed down the photosynthesis processes. Moreover, a more intensive growth of its photosynthetic organs was noted under the crop of barley, the cereal-legume mixture reduced the leaf area by 0.5 thousand m2 /ha, the pho-tosynthetic potential was 898...1051 thousand m2 day/ha.