EN
The technique employed for complementary seeding is one of the factors affecting the efficiency of this method of grassland renovation. It constitutes the basis of division of methods of complementary seeding into traditional and modern ones. The objective of this project is to assess modern methods of overdrilling of grasslands and their usefulness in Polish conditions. Two main methods of overdrilling were distinguished: 1/ strip seeding (rototiller and belt systems), 2/ slot seeding (based on cutting the sod - disk and knife systems - or based on tearing the sod - tine, coulter and spring-tine systems). Modern overdrilling techniques based on sowing of seeds into the surface soil layer by means of special drills guarantee a greater effectiveness of grassland renovation in comparison with oversowing. The usefulness of various methods of modern overdrilling for the renovation of permanent grasslands in Poland should be assessed in research centres employing comparative studies in combination with the estimation of the effect of overdrilling bearing in mind the specific conditions of meadow sites. The technique of overdrilling is one of the factors conditioning the success of the operation which can be either under- or overestimated. That is why the recognition of the influence of different systems of modern overdrilling on the effectiveness of meadow and grassland renovation requires further investigations. modern overdrilling operations are carried out using special drills and units. Unfortunately, such machines are very expensive and, therefore, seidom used in grassland management. It seems that the most sensible solution in present Polish conditions would be a joint purchase and utilisation of such equipment by a group of farmers under the supervision of a dairy co-operative, agriculture advisory centre or some other institution. Another option could be the provision of appropriate services by special companies equipped in proper machines.