As a result of three-year studies, we have established a growth in the yield and feed advantages of variable alfalfa in the variants with inoculation of seeds with virulent active strains of rhizobia. The total yield augmentation of green mass in the experimental variants over the three years of alfalfa life were 6.8–13.7 % compared to the control ones. The positive effect of inoculation with virulent active rhizobia strains on the total collection of dry matter was expressed in its increase in experimental conditions by 12.6–21.7 %. The highest yield of green mass, as well as dry matter was obtained in the variant with the inoculation of alfalfa seeds with the main production strain 425. The researched factor has a positive effect on the collection of feed units, digestible protein and feed protein units from 1 ha. The collection of feed units per hectare in the experimental versions increases by 1.1–1.3 times, the collection of digestible protein – by 1.2–1.4 times. The maximum substance of feed units and digestible protein per hectare was observed in the version with seed inoculation with strain 425a. The provision of a feed unit with digestible protein increases by 10.44–18.18 g or by 6.1–10.6 %.

As a result of studies of two variegated alfalfa fodder varieties selected by the FWRC FPA (Previously All-Russian Williams Fodder Research Institute) and the local population variegated alfalfa variety, it was found that Vega 87 formed a lower yield of green mass in the first year of growth. The yield of the Pastbischnaya 88 variety of the local population was 16 % higher; the superiority of both varieties over the variety Vega 87 was by 50 and 60% in the second year, and 13-15% in the third year of growth. Variegated alfalfa provided the following green mass harvest over the three years: Vega 87 - 31.55 t/ha (the lowest harvest), Pastbischnaya 88 - 39.55 t/ha, local population variegated alfalfa - 40.8 t/ha. The positive effect of inoculation with virulent active strains of the nodule bacteria on the total (per five cuttings) harvest of green mass was expressed in its increase in the experimental variants by 5.04-10.17 t/ha (6.8-13.7%) compared to the control variant. With the aim of adaptive intensification of fodder production, the creation of stable agrophytocenoses with variegated alfalfa with inoculation of seeds with virulent active strains of nodule bacteria is shown (the main production strain 425a showed best results).

Dactylis glomerata is an upland loose-flattened perennial herb, the most shade-tolerant of the common grasses. Low winter hardiness is an obstacle to the wide use of Dactylis glomerata as a grassland crop and a limiting factor for the release of varieties in the Primorsky Region. The devel- opment of highly winter-hardy intensive types of dwarf Dactylis glomerata is an important area of breeding work. The study aims to study promising source material of Dactylis glomerata for further use in creating new winter-hardy, high-yielding varieties. The authors have identified types for the yield of intensive varieties by studying the collection of Dactylis glomerata for the period 2018-2020 in the conditions of the Primorsky Region. The Dactylis glomerata plants reach full development and the highest yields in the third year of life. In terms of green matter yields in the two years of use, several Dactylis glomerata exceed the standard by 29-34%. These are variety samples 41821 Wild (Norway), 40280 Wild (Altai), and Sverdlovchanka 86 (Ural Agricultural Research Institute). The va- rieties Sverdlovchanka 86 (Urals Agricultural Research Institute), Dikorastushchaya (Primorskaya local) and 32028 Dikorastushchaya (Arkhangelskaya region) were distinguished by seed yield in the two years of use, having exceeded the standard by 113-153%. The winter hardiness of plants in the first winter is a limiting factor for Dactylis glomerata in Primorsky Krai conditions. The identified differences in the winter hardiness of plants allow the best of them to be used in selection. In the col- lection nursery of Dactylis glomerata, a variety of varieties with 100% winter hardiness of plants in the first winter after sowing were: 48113 Aukstuole (Lithuania), 41821 Wild (Norway), 40896 Wild (Kazakhstan), Sverdlovchanka 86 (Agricultural Research Institute), Wild (Primorsky Region).

In the field of fodder production, in most cases, low-yielding, old-age grass stands are used. One of the reasons for this is the low availability of grass seeds. For example, over the past 20 years, the production of grass-clover seeds has reduced by 3.4 times. Therefore, priority should be given to the seed production of leguminous grasses (including meadow clover). A large infestation of the arable soil layer with seeds and buds of annual and perennial weeds in almost all arable land in the Primorskiy Region is the most critical factor in reducing the yield of cultivated crops. The development of practical techniques for clearing fields of weeds is one of the vital links in the technology of increasing the output of fodder crops. The research aims to establish the effect of agronomic practices of cultivation and means of protection on the seed yield of meadow clover in the natural and climatic conditions of the Primorskiy Region. Clover is a crop sensitive to herbicides, with a limited period of their application. Therefore, inter-row treatments were carried out before the rows were closed, and chemical treatments were applied before the budding phase to preserve wild pollinators and bees. The varieties Ogonek, SibNIIK-10 and regionalised Kommandor were evaluated. Experimental data on the impact of agronomic practices of meadow clover cultivation and plant protection methods on the weediness of its crops and the yield quality of seeds under the conditions of the Primorskiy region were obtained. The use of herbicides against the background of inter-row treatment during the second year of clover planting helped reduce the weed infestation from 58.3 to 70% and increase the seed yield by 1.1-1.3 times depending on the variety.