Wplyw ugniatania gleby na plonowanie i system korzeniowy zycicy trwalej

The paper presents three years (1996-98) results of an investigation into the influence of tractor wheeling on the root development of Lolium perenne. The experiment was established as randomised block design with four replicates of five wheeling treatments. During the growing season of 1996 and 1997 the swards were pressed of the wheels of the tractor URSUS C-360 (weight 2056 kg) in an identical way. The passes were always made after cuts. The combination of the passes was follows: 0, 1, 2, 4 and 6 passes on the plots of 7 m². After 3rd cut in 1998 roots were taken for investigation. Changes in soi physical properties were observed. Penetrometer resistance increase in upper 30 cm soil layer according to number of passes. This mean that soil conditions for root development changed. Roots of investigated species grow better in lightly compacted soil. Results showed that tractor wheeling reduced yielding of Lolium perenne up to 27% in proportion with number of passes. These changes in plant yielding are result of changes in soil environment and damages to plants above ground level.