Effect of living mulches and conventional methods of weed control on weed occurrence and nutrient uptake in potato

The aim of the study was to determine the biomass, abundance and species composition of weeds, as well as macroelement uptake in potato weeded using mechanical, mechanical– chemical and mechanical control combined with the sowing of living mulches of white mustard, common vetch, Persian clover and tansy phacelia. Abundance and biomass of the weeds was the most effectively limited by the mechanical treatments. The effectiveness of mechanical treatments in weed biomass reduction was 2.5–fold lower. The mechanical treatments more effectively limited the number of monocotyledonous than dicotyledonous weeds. Living mulches increased the efficiency of mechanical weeding by affecting both weed biomass development and weeds abundance. The living mulch that most effectively limited the growth of weed biomass was white mustard, while vetch was effective to reduce of the number of monocotyledonous weed and Persian clover for dicotyledonous weeds. The most frequently occurring weed species were Galinsoga parviflora, Chenopodium album and Echinochloa crus-galli. The share of N accumulated in the biomass of neighboring plants constituted from 5% to 34%, P from 6% to 38%, K from 5% to 36%, Ca from 27% to 190% and Mg from 12% to 55% of the amount of these nutrients absorbed by potato plants. Mechanical treatments plus living mulches, especially Persian clover, may be useful in organic cropping systems due to their effectiveness at reducing weed abundance and biomass and relatively low nutrient uptake compared with weeds.