Effect of integrated paddy-fish-duck-azolla culture on the growth, yield, and water quality of rice

Abstract

Rice is the principal staple crop of West Bengal; however, continuous monoculture has led to reduced profitability and deterioration of soil health. To address these limitations, a study was undertaken to enhance rice system productivity and sustainability by integrating fish, ducks, and Azolla in paddy fields under an Integrated Farming System (IFS) framework. The experiment was conducted during the rainy seasons of 2022 and 2023 at the Instructional Farm of Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal. The trial followed a split-split plot design with three replications. Integration of paddy with fish, duck, and azolla significantly enhanced the growth and yield of rice. Rice yield increased by 15% with ducks and by 17%, 15%, and 4% with Tilapia, Rohu, and Catfish, respectively. Ranjit (4.99 t/ha) outperformed Bheema (4.69 t/ha). Tilapia recorded the highest fish yield, especially with ducks (3.01 t/ha vs. 1.70 t/ha). Weight gain ducks exceeded 110% under mixed culture. Straw yield also improved significantly due to the introduction of duck fish and azolla. In composite paddy-fish-duck-azolla culture, the nutritive value of standing water, such as N and P levels, rose during peak crop stages, indicating a nutrient-rich environment supportive of better crop and fish growth. Among all treatment combinations, the combination of Duck + Azolla + Tilapia + Ranjit produced the highest rice grain yield (5.13 t/ha) and fish yield (3.09 t/ha), confirming its superiority over the control. The economic analysis further supported this combination as the most effective and profitable model. Thus, integrating ducks, Azolla, and Tilapia in rice fields offers a sustainable, productive, and ecologically balanced solution for improving paddy-based systems in lowland areas of North Bengal.