Sunflower Residue Incorporation Suppresses Weeds, Enhances Soil Properties and Seed Yield of Spring-Planted Mung Bean
ABSTRACT: Continuous and excessive use of herbicides to control various weed biotypes is posing severe threats to soil and human health. Nevertheless, the strategy of using allelopathic crop residues and water extracts for weed control seems to be a sustainable and friendly option to reduce dependence on synthetic herbicides. In addition to controlling weeds, residues of allelopathic crops positively affected soil health. A two-year field study was carried out to examine the impact of sunflower residues on soil properties, weed dynamics and productivity of mung bean. The study was comprised of five treatments viz., control, sunflower water extracts at 10 and 20 L ha-1, and sunflower residues incorporation at 4 and 6 ton ha-1. Results indicated that application of sunflower water extracts reduced weed density by 5-26% and weed dry weight by 9-31%, while sunflower residue incorporation caused 44-57% reduction in weed density and 58-70% reduction in weed dry weight compared with the control. At mung bean harvest, total nitrogen and organic matter in soil were increased by 86% and 74%, respectively, with the incorporation of sunflower residues at 6 ton ha-1 as compared with the control. In case of soil enzymes, alkaline phosphatase and dehydrogenase were recorded at 186 mg NP g-1 soil h-1 and 38 mg TPF g-1 soil h-1, respectively, when sunflower residue was incorporated at 6 ton ha-1. In conclusion, sunflower residue incorporation at 6 ton ha-1 improved soil health, suppressed weeds and resulted in better seed yield (36%) and profitability (339 $ ha-1) of spring-planted mung bean.