Impact of drip fertigation on maize growth and productivity under conservation agriculture practices in the eastern Indo-Gangetic plains of India

A two-season field experiment (2022-23 and 2023-24) was conducted at the International Rice Research Institute – South Asia regional Centre, Varanasi, India to evaluate the performance of rabi maize in a five-year long term conservation agriculture-based rice-maize system under surface and subsurface drip fertigation. The experiment was followed a randomized complete block design with nine treatment combinations and three replications. The treatment, zero till maize – direct seeded rice system under subsurface drip fertigation and 100 % recommended nitrogen (ZTM-DSR-SSD-100N) exhibited the highest plant height (213.7 cm), dry matter accumulation (316.0 g plant-1) and leaf area index (LAI) (6.74 at 90 DAS), outperforming other treatments by 13.9 %, 35 % and 21 %, respectively, over the lowest-performing CTM-PTR-100N. Yield attributes followed a similar trend, with ZTM-DSR-SSD-100N recording the highest cobs per hectare (72.18), cob length (19.77 cm) and grains per cob (559.94), with 27.6 % higher grain yield (7.43 t ha-1) over least-performing treatment, ZTM-PTR-75N. Enhanced resource efficiency under SSD ensured precise water and nutrient delivery, promoting superior canopy and cob development. Conversely, conventional puddled systems exhibited reduced yields due to waterlogging and inefficient nutrient use. This study highlights the superiority of SSD over traditional methods, showcasing its potential to improve maize productivity and resource-use efficiency under CA-based systems. These findings emphasize the importance of advanced irrigation and nitrogen management strategies for sustainable intensification in the eastern Indo-Gangetic plains.