BACKGROUND: Application of plant mulches plays a significant role in development and expansion of sustainable farming systems. OBJECTIVES: Assessment effect of chemical and non-chemical weeds management methods on weeds density and biomass and the properties of soil, including microbial biomass carbon (MBC) and soil organic carbon (SOC) in potato cultivation. METHODS: Research was conducted in 2015 in two agricultural research stations of Alarogh and Samian in Ardabil city according randomized complete block design with three replications. The treatments included: 1) Trifluralin herbicide (TR), 2) Metribuzin herbicide (ME), 3) cultivator practice (CU), 4) wheat straw mulch (WH), 5) canola straw mulch (CA), 6) black plastic mulch (BPL), 7) transparent plastic mulch (TPL), 8) weed infested (WI), and 9) weed free (WF). Soil sampling was conducted at three stages. The first stage included control index sampling (CIS). The second and third soil sampling performed at 25 and 45 day after the treatment application. RESULT: All treatments were affected by weed management methods (P≤ 0.01). The lowest density of weeds was related to the WH. Most weeds density was counted as 99.1 plants.m-2 of WI treatment. The WH deceased weeds density as 84% compared to weed infested. CA treatment deceased weeds density as 79% compared to WI treatment. Though, weed biomass in the treatments of transparent and BPL compared to the WI treatment had the highest weeds biomass as 48 and 40%, respectively. The lowest weed biomass was observed in CA and WH by 16 and 18% after the WI. CONCLUSION: The highest rate of MBC observed in WH and CA treatments at the second and the third soil sampling stages, respectively, compared with other experimental treatments. WH and CA increased the rate of MBC in the second and the third sampling stages in comparison with CIS. The highest SOC was observed in WH and CA at the second and the third soil sampling stages. پرونده مقاله