In order to evaluate yield and yield components in intercropping barley with vetch, a two-year field experiment was conducted at the Agricultural and Natural Resources Research Station of Miandoab. The arrangement consisted of 9 mixing treatments with densities of 200 Vetch plant + 300 Barley plant, 200 Vetch plant + 500 Barley plant, 200 Vetch plant + 700 Barley plant, 400 Vetch plant + 300 Barley plant, 400 Vetch plant + 500 Barley plant, 400 Vetch plant + 700 Barley plant, 600 Vetch plant + 300 Barley plant, 600 Vetch plant + 500 Barley and 600 Vetch plant + 700 Barley plant per square meter and sole culture of both crops. The experimental design was a randomized complete block design with four replications. The result showed The highest spikes per square meter, thousand kernel weight, biological yield, and grain yield in barley were observed in the sole culture of barley. Also, the highest plant height, number of seeds per plant, thousand kernel weight, biological yield, and grain yield in vetch belonged to the sole culture of vetch. However, the highest Land equivalent ratio (LER) belonged to treatments of 200 Vetch plants + 500 Barley plants by 1.49,

In order to investigate the changes in weed flora in the irrigated wheat fields of Isfahan county over a 15-year period (from 2019 to 2004), a systematic sampling of weeds was conducted in 100 farms with W pattern during wheat tillering to stem elongation stages. In 2004, the dominant weed species was winter wild oat (Avena ludoviciana) with a abundance index of 76.1; however, in 2019 three weed species, including winter wild oat, wild barley (Hordeum spontaneum), and littleseed canarygrass (Phalaris minor) were recognized as the dominant species with abundance indices of 70.1, 42.3, and 28.6, respectively. In 2004, the dominant broadleaf weed species were lambsquarters (Chenopodium album) with a dominance index of 67.9 and prostrate knotweed (Polygonum aviculare) with a dominance index of 31.96. However, in 2019, the highest dominance indices were observed in lambsquarters, prostrate knotweed, and Flixweed (Descurainia Sophia) with abundance indices of 78.4, 38.5, and 39.04, respectively. The correlation between weed distribution and soil factors (nitrogen, phosphorus, potassium, soil texture, and electrical conductivity), crop rotation, and herbicides was examined using canonical correspondence analysis (CCA). Littleseed canarygrass, wild barley, field brome (Bromus commutatus), licorice (Glycyrrhiza glabra), hoary cress (Cardaria draba), and yellow sweet clover (Melilotus officinalis) showed the highest correlation with soil nitrogen levels.