A field experiment was conducted in a randomized block design with different organic weed management treatments including water extracts of sorghum, sunflower, Parthenium, Lantana and purplenut sedge plants, each 15 L/ha applied at 15 and 30 days after seeding (DAS) alongwith paddy straw mulch 5 t/ha. The predominant weed species were Cyperus rotundus L. (45%), Digitaria sanguinalis (L.) Scop. (15%), Borreria hispida (L.) K. Schum. (7%). Application of paddy straw mulch 5 t/ha proved to be best in controlling weeds and promoting yield components and yield of groundnut as well as realizing higher returns followed by sunflower water extract spray 15 L/ha. The efficacy of Parthenium water extract and purple nutsedge water extracts were poor in controlling weeds and enhancing yield of groundnut. The reduction in groundnut pod yield due to unchecked weed growth was 52.53% and 37.18% compared to pendimethalin 1.0 kg/ha + hand weeding (HW) at 30 DAS and paddy straw mulch 5 t/ha, respectively. Pre-emergence application of pendimethalin1.0 kg/ha followed by HW recorded significantly higher number of effective Rhizobium nodules/ plant whereas paddy straw mulch 5 t/ha recorded significantly higher count of soil microorganisms.