The Microscopic Mechanisms Involved in Superexchange

In earlier work, we previously established a formalism that allows to express the exchange energy J vs. fundamental molecular integrals without crystal field, for a fragment A–X–B, where A and B are 3d1 ions and X is a closed-shell diamagnetic ligand. In this article, we recall this formalism and give a physical interpretation: we may rigorously predict the ferromagnetic (J < 0) or antiferromagnetic (J > 0) character of the isotropic (Heisenberg) spin-spin exchange coupling. We generalize our results to ndm ions (3 £ n £ 5, 1 £ m £ 10). By introducing a crystal field we show that, starting from an isotropic (Heisenberg) exchange coupling when there is no crystal field, the appearance of a crystal field induces an anisotropy of exchange coupling, thus leading to a z-z (Ising-like) coupling or a x-y one. Finally, we discuss the effects of a weak crystal field magnitude (3d ions) compared to a stronger (4d ions) and even stronger one (5d ions). In the last step, we are then able to write the corresponding Hamiltonian exchange as a spin-spin one.

Energy efficiency of improved technologies and modern systems of bulk feed production of high quality on haylands of the Non-Chenrozem region

Исследования проводили в ФНЦ «ВИК им. В. Р. Вильямса» на базе трёх долголетних полевых экспериментов: в опыте 1 изучали многоукосное использование ранних и среднеспелых злаковых травостоев в среднем за 28 лет (1993–2020 годы), в опыте 2 — люцерно-злаковые травостои для позднего звена укосного конвейера в среднем за 7 лет пользования (2013–2020 годы), в опыте 3 проведено сравнение четырёх технологических систем создания и использования травостоев за последние 28 лет (в среднем за 47–74-й годы пользования, 1993–2020 годы). Цель исследований — определение агроэнергетической эффективности 15 технологий по созданию усовершенствованных злаковых и бобово-злаковых травостоев, а также шести систем ведения долголетних сенокосов при производстве сырья для заготовки высококачественного сена и сенажа. Применение нового метода агроэнергетической оценки антропогенных затрат не только подтверждает высокую экономическую эффективность создания сеяных травостоев на лугах, но и впервые в конкретных (цифровых) показателях устанавливает роль разнообразных природных факторов. На долголетних злаковых травостоях (в течение 28 лет жизни трав) обеспечивается производство сырьевой массы для заготовки объёмистых кормов (сена и сенажа) первого и второго классов. Совокупные антропогенные затраты энергии на этих травостоях в среднем за 28 лет составили 16,3–17,1 ГДж/га при двухукосной и 23,2–23,6 ГДж/га — при трёхукосной технологии, на люцерно-злаковых травостоях при двух укосах в среднем за 7 лет — 5,2–5,8 ГДж/га. Затраты окупались сбором обменной энергии на ранних и среднеспелых агроценозах с доминированием корневищных злаковых видов в 2,8–3,3 раза, а на люцерно-злаковых травостоях — в 10,6–11,0 раз. В структуре производства обменной энергии основная её часть обеспечивалась за счёт возобновляемых природных факторов: 67–70% — на злаковых травостоях и 90% — на бобово-злаковых долголетних травостоях. The research took place at the Federal Williams Research Center of Fodder Production and Agroecology and consisted of three long-term field trials. The trial 1 was aimed at studying the multi-cut use of short- and mid-season gramineous for 28 years (1993–2020). The trial 2 tested alfalfa-gramineous swards for late cutting for 7 years (2013–2020). The trial 3 compared four technological systems of sward development and cultivation for the last 28 years (1993–2020). The aim of this research was to determine the energy efficiency of 15 cultivation technologies for optimization of gramineous and legume-gramineous swards as well as six systems of long-term hayfield cultivation to obtain high-quality hay and haylage. New method evaluating anthropogenic costs proved high economic efficiency of sown swards but also showed the impact of various natural factors. Long-term gramineous swards (28 years of life) provided raw material for bulk feed production (hay and haylage) of the first and second grade. For such swards total anthropogenic costs amounted to 16.3–17.1 GJ ha-1 under two cuts and 23.2–23.6 GJ ha-1 — under three cuts for 28 years. For alfalfa-gramineous swards total anthropogenic costs amounted to 5.2–5.8 GJ ha-1 for 7 years. The costs were paid back by 2.8–3.3 times through the exchange energy yield from short- and mid-season ecosystems with higher proportion of rootstock grasses, from alfalfa-gramineous swards — by 10.6–11.0 times. The great part of exchange energy was provided through renewable natural factors: 67–70% — from gramineous swards and 90% — from the legume-gramineous ones.

Feeding of high-productive cows with protected plant fats

С целью изучения эффективности использования сухих защищённых растительных жиров, приготовленных по различным технологиям (Ultra Feed F – гидрогенизированный жир и Extra Feed F – фракционированный жир (Россия)), в кормлении высокопродуктивных молочных коров был проведён научно-хозяйственный опыт в экспериментальном хозяйстве «Клёново-Чегодаево» (Москва). В эксперименте, проведённом на трёх группах коров голштинизированной чёрно-пёстрой породы, с удоем 7000 кг молока за лактацию, по 10 голов в каждой, установлено, что повышение концентрации обменной энергии в сухом веществе рациона кормления коров с 10,7 до 11,0 МДж/кг в период с 21-го по 120-й день лактации, за счёт включения в состав рациона коров опытных групп исследуемых защищённых жиров в количестве 300 г/гол/сутки, способствовало увеличению удоя молока 4% жирности за 100 дней опыта на 9,7 и 11,0% по сравнению с контролем, а продукции молочного жира и белка — соответственно на 9,6–11,0% и 7,4–8,3%, затраты кормов, выраженные в ОЭ, снизились на 4,9–5,2%. При этом сервис-период, который составил 138,2 дней в контрольной группе, в опытных группах сократился соответственно до 121,4 и 126,5 дней. Экономические расчёты показали, что себестоимость 0,1 т молока базисной жирности у коров опытных групп снизилась на 12,1–19,6 руб., или на 0,6–0,9%, по сравнению с контролем, при одновременном получении дополнительной прибыли в обеих опытных группах в размере 2063,6–2588,3 руб. на голову. The experiment was carried out at the Research Farm “Klenovo-Chegodaevo” (Moscow). The aim was to analyze the effectiveness of dry protected plant fats in dairy cow feeding. The fats were prepared using different technologies (Ultra Feed F – hydrogenated fat and Extra Feed F – fractionated fat (Russia). The experiment included three groups of Holstein black-and-white cows producing 7000 kg of milk per lactation. Each group consisted of 10 heads. Feeding cows with 300 g of protected fats daily increased exchange energy concentration in dry matter from 10.7 to 11.0 MJ/kg from the 21st to 120th day of lactation leading to the increase of 4% milk yield by 9.7 and 11.0% as well as milk fat and protein — by 9.6–11.0% and 7.4–8.3%, respectively. Forage consumption expressed as exchange energy dropped by 4.9–5.2%. Service period decreased from 138.2 days to 121.4 and 126.5 days. Economic efficiency of 0.1 t of 4% milk reduced by 12.1–19.6 rubles, or 0.6–0.9%. Both experimental groups provided the additional profit of 2063.6–2588.3 rubles per head.

The effect of mineral fertilizers on the yield and quality of hay of leguminous grasses

The article presents the results obtained in the stationary experiment of the Novozybkovskaya SHOS. In the experiment, single-species crops of yellow alfalfa, boneless stalk and grass mixtures based on them were studied against the background of various doses of potash fertilizers (K120-180). The influence of potash fertilizers on the yield and quality of legumes and cereals, their mixed crops and a decrease in the content of 137Cs in hay is considered. It was found that the highest yield of hay of perennial grasses in both the first and second mowing was obtained in the P60K180 variant. The highest level of hay yield among the studied crops was noted in a grass mixture of yellow alfalfa with a boneless stalk. In terms of the yield of feed units and exchange energy per hectare, the alfalfa + stalk grass mixture exceeded single-species crops. Studies have established that the guaranteed receipt of normatively clean feeds based on yellow alfalfa, boneless stalk and grass mixtures based on them is provided by the use of phosphorus-potassium fertilizer in a dose P60K120.

Agro-energetic efficiency of improved technologies of pasture fodder production in dry grasslands of the Non-Chernozem region

Based on the modern method of agro-energetic evaluation of anthropogenic non-renewable energy sources and natural renewable resources, scientific evidence of high economic efficiency of green fodder production on cultivated pastures is presented. Two field experiments on improving the composition of grass herbage with the participation of domestic zoned varieties of ryegrass pasture and Festulolium, as well as similar grass mixtures with the inclusion of legumes: creeping clover and meadow clover were carried out. The total anthropogenic expenses were determined as well as the recoupment of their exchange energy by 3-4 and even 10 times in the produced forage. The role of natural factors in the structure of the received exchange energy was determined. This serves as a theoretical basis for the economic efficiency of indicators of cultivated pastures created by resource-saving technologies: mainly due to the longterm use of cereal grasses (for 14 years) or the receipt of biological nitrogen on legume-grass stands, which replaces the use of mineral nitrogen fertilizers in the dose N126-131 per year (average for 7 years) on dry grasslands of the Nonchernozem zone.

Agro-energy efficiency of improved technologies for the production of pasture fodder in upland meadows of the Central non-Chernozem region

On the basis of a modern method of agro-energy assessment of anthropogenic non-renewable energy sources and natural renewable resources, scientific evidence of the high economic efficiency of green fodder production on cultivated pastures is presented. Two field experiments were carried out to improve the composition of cereal grasses with the participation of domestic zoned varieties of perennial ryegrass and festulolium, as well as similar grass mixtures with the inclusion of legumes: white clover and red clover. The total anthropogenic costs have been determined, the return on their exchange energy in the produced feed was 3-4 times and even 10 times, the role of natural factors in the structure of the obtained exchange energy was established. This serves as a theoretical basis for the indicators of the economic efficiency of cultivated pastures created using resource-saving technologies: mainly due to the long-term use of cereal grasses (for 14 years) or the supply of biological nitrogen on legume and cereal grasses, replacing the use of mineral nitrogen fertilizers at a dose of N126-131 per year (on average for 7 years) on dry meadows of the Non-Chernozem zone.