Evaluating the efficacy of different organic amendments on crop performance and nutrient uptake in black cumin (Nigella sativa L.)

Organic farming may improve soil and plant health, reducing the use of agrochemicals that have adverse impacts on soil health, productivity, and the environment. Cultivation of black cumin (Nigella sativa L.) in India’s Eastern zone is difficult owing to nutritional constraints and environmental unpredictability. To address these concerns and increase production of black cumin, the potential of organic amendments, such as vermicompost and farmyard manure, and organic substances like panchagavya and vermiwash, has been tested to determine if they can improve plant growth, yield, essential oil production, and nutrient absorption by boosting nutrient uptake. The experimental design followed a randomized complete block design with nine treatments and three replications. Results revealed that farmyard manure mixed with panchagavya significantly increased plant height (22.32%), primary branches (23.24%), secondary branches (19.99%), dry matter (18.46%), essential oil (22.72%), and NPK absorption (52.60%, 54.16% 39.27%) as compared to control groups. The synergy between vermicompost and panchagavya was particularly evident in plant height (25.52%), primary branches (29.05%), secondary branches (29.54%), dry matter (26.51%), essential oil (29.55%) and NPK absorption (78.69% 119.07%, 45.50%), as compared to control groups, indicating improved light interception and nutrient-driven partitioning in response to vermicompost application. Favourable weather conditions, such as moderate rainfall and warmth, amplify these advantages, demonstrating the importance of environmental context in agronomic outcomes. Overall, the research recommends that integrating vermicompost with panchagavya improves fertilizer usage efficiency and yield of black cumin, providing a scalable, environmentally friendly approach for increasing crop productivity in resource-limited agroecosystems in eastern India.