FORMATION OF THE YIELD OF THE ABOVE-GROUND MASS OF WHITE SWEETCLOVER IN SINGLE-SPECIES AND COMBINED CROPS IN THE CONDITIONS OF THE RIGHT-BANK FOREST STEPPE OF UKRAINE

Abstract

An effective way of forming an effective fodder base and reducing the cost of livestock production is the cultivation of perennial leguminous grasses, which are characterized by high fodder and agronomic value. The introduction of perennial leguminous grasses in crop rotation contributes to the inclusion of atmospheric nitrogen in the biological cycle of the air, reducing the ecological burden on the environment and obtaining cheap plant protein at low rates of expensive nitrogen mineral fertilizers. However, not all crops are able to form a high and stable yield under any weather conditions. Therefore, in the conditions of climatic changes, an important condition for sustainable field fodder production is the use of species and varieties characterized by increased resistance to stressful hydrothermal factors. The culture of Melilotus albus is a valuable fodder, honey-bearing and phytoremedial plant, which is characterized by high ecological plasticity and efficient use of agro-climatic resources. In fodder production, the crop can be used for harvesting hay, silage, and also fed as green and pasture fodder. Cultivation of mixed crops of leguminous and cereal crops makes it possible to obtain fodder that better meets the physiological needs of animals. However, today there is not enough scientific information on the peculiarities of growing Melilotus albus for fodder in intercropping with cereal crops. The purpose of the research was to establish the peculiarities of the formation of the productivity of the vegetative mass of Melilotus albus in single-species and binary crops with cereal components, depending on the technological methods of cultivation. The research was conducted during 2015-2017 at the experimental field of the Department of Fodder Production, Land Reclamation and Meteorology in the conditions of the Agricultural Research Station of the SS NULES of Ukraine. The research was carried out during 2015-2017 at the experimental field of the Department of Fodder Production, Land Reclamation and Meteorology in the conditions of the VP NUBiP of Ukraine "Agronomic Research Station". The field experiment was established according to the scheme: factor A - grass mixtures: 1 – Melilotus albus (control), 2 – Melilotus albus + Zea mays, 3 – Melilotus albus + Panicum miliaceum, 4 – Melilotus albus + Sorghum drummondii, 5 – Melilotus albus + Sorghum saccuratum; factor B – seeding rate of white Melilotus albus: 1 – 16 kg/ha (control), 2 – 18 kg/ha, 3 – 20 kg/ha, 4 – 22 kg/ha; factor C – fertilization: without fertilization (control), N45P45K45, N60P60K60, N60P90K90. In the experiment, Melilotus albus varieties of the two-year Enei variety, Zea mays hybrid – Kadr 267 MV (FAO 260), Panicum miliaceum variety – Kozatske, Sorghum saccuratum hybrid – Dovista, Sorghum drummondii variety – Bilyavka were used in the experiment. The rate of sowing of the cereal component in binary cereal-legume grass mixtures was 70% of the full: Panicum miliaceum – 2.25 million similar seeds per 1 ha (20 kg/ha), Zea mays – 60 thousand similar seeds per 1 ha (20 kg/ha ), Sorghum drummondii – 1.5 million similar seeds per 1 ha (15 kg/ha), Sorghum saccuratum – 0.375 million similar seeds per 1 ha (15 kg/ha). Phosphorus-potassium fertilizers were applied in the form of simple superphosphate (19.5%) and potassium chloride (56%) in the fall for the main tillage, nitrogen fertilizers in the form of ammonium nitrate (34.5%) were applied in the spring for pre-sowing cultivation. The area of the accounting plot is 25 m2, repetition is four times. The soil of the experimental site is a typical low-humus chernozem, the 0-20 cm layer of which contains mobile phosphorus (according to Machigin) – 40-55 mg/kg of soil, exchangeable potassium – 150-165 mg/kg of soil, and easily hydrolyzed nitrogen according to Kornfield – 140-160 mg/kg of soil, the pH of the salt extract is 6.7-7.0. The years 2015 and 2017 were extreme in terms of hydrothermal conditions, which were characterized by significant increases in air temperature during the vegetation period against the background of long periods without rain. The growth and development of plants in 2016 took place in conditions close to long-term values in terms of the main weather parameters. It was established that with an increase in the sowing rate of the leguminous component, the yield of above-ground mass decreased both in monospecies and in its simultaneous sowing with cereal crops, regardless of the rate of application of mineral fertilizers. The highest volumes of growth of vegetative mass in all variants of the experiment were obtained under the condition of application of mineral fertilizers with the rate of N60P90K90. The maximum yield of green fodder was provided by the technological model, which provided for the cultivation of binary crops of Melilotus albus with Sorghum drummondii at the sowing rate of leguminous crops of 16 kg/ha and the application of N60P90K90 – 51.5 t/ha, which exceeded the control (single-species sowing of Melilotus albus with the sowing rate of 16 kg/ha) by 13.4 t/ha. This variant was also characterized by the highest intensity of growth of fodder mass already from the thirtieth day after germination and the best foliage of fodder mass in the period of harvest maturity – 39.73-41.17% or 10.80- 13.97 t/ha. The smallest increase under such an interaction of factors was provided by leguminous-cereal phytocenosis with Sorghum saccuratum – 5.4 t/ha.