Cultural weed management through intercropping helps in weed suppression, resulting in improved crop productivity. Cereal–legume intercropping is one of the major eco-friendly approaches to suppress weeds and improve crop performance and soil fertility. Therefore, a two-year field experiment was carried out at the campus of Ramakrishna Mission Vivekananda Educational and Research Institute, Ranchi, Jharkhand during the monsoon season of 2023 and 2024 in a randomized block design with three replications using eight cropping systems. Results revealed that sole black gram ensured highest weed control efficiency (55.9%), followed by intercropping system of finger millet and black gram (1:2) (49.5%). Finger millet + black gram (1:2) and sole black gram recorded higher growth attributes and yields of finger millet and black gram, respectively. However, finger millet + black gram (1:2) also recorded high growth and yield attributes of black gram. System productivity was maximum in sole black gram (4730 kg/ha), followed by intercropping system of finger millet and black gram (1:2) (3900 kg/ha), along with protein content (23.4%) and consequently, the production economics (net return: Rupees 56830/ha; benefit: cost of 1.90). It also resulted in the highest residual soil fertility. Additionally, the combined land equivalent ratio (1.44) was higher in the 1:2 intercropping system of finger millet and black gram, indicating a 44% yield advantage. Thus, in Eastern Plateau and Hill Zone of India, an intercropping system of finger millet and black gram (1:2) is recommended for cultivation in monsoon to achieve high weed suppression, crop productivity, and economic profitability.

A field study was conducted to evaluate the effect of weed management practices in the main crop on growth, yield and economics of rice- ratoon rice cropping system in two consecutive years i.e., 2014–15 and 2015–16. The result showed that Cyperus difformis was the most dominant weed in the main rice crop, whereas Ludwigia adscendes was the dominant weed in ratoon rice. In weed-free plots, the main crop recorded the highest productivity of 47.52 kg/ha/day, whereas the ratoon crop registered productivity of 37.70 kg/ha/day which was the 79.3% of the main crop productivity. In the weedy plot, crop-weed competition caused 28.8 and 37.5% reduction in energy use efficiency and energy productivity of the rice-ratoon rice cropping system respectively. Yield reduction of 37.3 and 43.6% in the main crop and ratoon crop respectively recorded due to weed infestation in weedy check. All the weed control practices registered an increase in system productivity, nutrient uptake and energy use efficiency. Among the herbicidal treatments, application of bensulfuron-methyl + pretilachlor (60 + 600 g/ha) at 10 DAS to the main crop registered a higher net return of USD$ 639.2 and 260.1 of main crop and ratoon crop, respectively. Hence it can be recommended for weed management in rice-ratoon rice cropping system.