This study aims to determine the effect of purslane weed density on the growth and yield of soybeans. This research was carried out at the Experimental Farm of the Faculty of Agriculture, Syiah Kuala University, Darussalam, Banda Aceh from November 2021 to February 2022. This study used a completely randomized design (CRD) with a non-factorial pattern with 6 treatments of purslane weed density, namely D0 = 0 without weeds, D1 = 2 weeds per plant, D2 = 4 weeds per plant, D3 = 6 weeds per plant, D4 = 8 weeds per plant, D5 = 10 weeds per plant. The variables observed included dry weight of weeds, plant height rate, dry weight of plant, number of pods per plant, number of seeds per plant, weight of 100 seed and weight of seeds per plant. The results showed that the density of purslane weeds had an effect on weed dry weight, plant height rate, plant dry weight, number of pods per plant and seed weight per plant. Purslane weed density of 4-10 weeds per plant can reduce seed weight per plant.
Keywords: Soybean, weed, density,weed competition