IOT based irrigation water management in rice – rice system for enhancing water use efficiency and sustainability

India, with a population of 1.4bn, is among the most water-stressed countries in the world. A report from the government's NITI Aayog think-tank in 2019 estimated that 600mn Indians faced "high to extreme water stress", many cities in India would run out of groundwater in a matter of years. With about half the workforce employed in agriculture, this poses a considerable challenge, not just to farmers but also to the economy. Prime Minister Narendra Modi has repeatedly called on citizens "to save every drop of water" that they can. "We should use water sparingly, like a sacred offering," he said in an address released on World Water Day in March 2022. Rice is a water-guzzling crop (consumes more than 60 % of total irrigation water in India) cultivated mostly through inefficient irrigation methods (5000 lt of water for 1 kg grain) which leads to poor water use efficiency and many environmental problems. In this paper, various rice crop establishment methods and irrigation methods can reduce the water and supply the water in a precise way to enhance water productivity. The experiments conducted at IIRR for the past 10 years indicated the superiority of these establishment methods ( SRI and DSR ) over flooded rice in enhancing the water productivity significantly ( SRI -6.18 and DSR -6.05 t ha-1) compared to NTP (5.45 t ha -1). The lowest water productivity was in the Normal transplanted flooded rice system (4.27) during 2015- 2017. Hence, these methods provide viable crop establishment methods for flooded rice production. Further, innovative as well as novel technologies like smart irrigation using mechanical water level indicators ( CIAE developed AWD pipe), sensors and IoT, water stress identification ( cultYvate) and irrigation are gaining momentum and need for upscaling of these technologies. Application of water through alternate wetting and drying (AWD) saved around 11-14 percent of the total water requirement per season. Irrigation by AWD and IOT based (implemented through water level indicator developed by ICAR-CIAE) recorded significantly superior irrigation water productivity and WUE in the rice-rice system.