Changes of weed abudance in winter wheat crop using log-term reduced tillage and direct seeding

Results of 2009-2010 investigation period conducting long-term field experiment at Experimental Station of Lithuanian University of Agriculture on Calc(ar)i-Endohypogleyic Luvisol are presented in this paper. Aim of the investigation was to evaluate changes of annual and perennial weed abundance in intensively grown winter wheat crop applying reduced tillage and direct seeding. Density of annual and perennial weed seedlings in winter wheat crop at tillering stage was higher in plots where shallow ploughing, shallow or deep loosening, or direct seeding was applied as compared with that in conventionally ploughed plots. At milk stage of winter wheat crop higher number of annual weed species was also in plots with reduced and zero tillage than that in ploughed plots. At this stage density of perennial weeds was higher only in plots where direct drilling was applied as compared with that where other investigated soil tillage types were used. Shallow ploughing and deep loosening did not increase air-dry weight of annual weeds in winter wheat crop as compared with conventionally ploughing. Only direct drilling enable increase of air-dry weight of perennial weeds. Reduced soil tillage did not increase total weed air-dry biomass as compared with conventional tillage. Direct seeding stimulated total weed abundance increase in intensively grown winter wheat cropVytauto Didžiojo universitetasŽemės ūkio akademij