Czynniki warunkujace podsiew uzytkow zielonych - roslina.

The aim of the project is to present the role of the plant in effective complementary seeding of grasslands. Two groups of issues were distinguished. The first group is associated with the plant introduced by means of complementary seeding – criteria of species and variety selection, factors affecting sprouting, emergence as well as the growth and development of seedlings. The second group comprises problems associated with the influence of primary vegetation, plants present in the sward of grasslands which are being oversown - plant compatibility and restriction of their effect on seedlings. The paper is the result of studies of literature and own investigations on grassland renovation and, first of all of the author's own considerations. The role of the plant in the process of grassland renovation by complementary seeding is very important. It cannot be limited to the selection of species or cultivar of plants sown under. There is a whole domain of plant properties, beginning with the phase of sprouting and emergence to the stage of full feed utilisation which play a decisive role in the effectiveness of the sod seeding process. Furthermore, this effectiveness is also influenced by the sward vegetation itself into which the introduced species or cultivars are sown. Studies on sod seeding in Poland have continued for a long time, albeit with varying intensity and influenced by altering current technical possibilities. Complementary seeding defined as a method of grassland renovation already seems to be a thing of the past. In future it will be more and more treated as a managing treatment of meadows and pastures similar to fertilisation or irrigation. Pro-ecological character of oversowing and overdrilling rnakes this treatment applicable not only on grasslands but also on objects not connected with forage utilisation, such as lawns and marginal areas. This operation may well serve to increase floristic diversity of meadows, but equally importantly it can be used to re-introduce lost species and reconstruction of grass communities. There are high expectations concerning the plant as the key element in the process of cornplementary seeding. The important question is whether the issue of oversowing and overdrilling is also taken under consideration in the process of breeding work and seed production