Indian Prime Minister Manmohan Singh called Saturday for a second \"green revolution\" to feed the country\'s burgeoning population that is forecast to overtake China in numbers by 2025. Under India\'s \"Green Revolution\" in the 1960s and 70s -- seen as one of the world\'s most successful agricultural turnarounds -- planting of high-yield varieties of wheat and rice resulted in a sharp output rise. \"We all look back proudly to our green revolution which helped us overcome food shortages and banish the spectre of starvation,\" Singh told a conference of agricultural scientists. But now, \"we clearly need a second green revolution that is broad-based, inclusive and sustainable\", he said, noting agriculture productivity has plateaued and \"yields continue to be much lower than what is attainable\". Experts say India must increase yields to feed its population which already stands at 1.21 billion people. India is expected to supplant China as the world\'s most populous nation by 2025, according to Indian official projections. Singh said the agriculture sector is growing at three percent annually -- one percent below target -- helping drive food inflation that has spiralled faster than in most major economies, causing huge misery for India\'s poor. India is poised to introduce a food security bill aiming to guarantee cheap food grains for nearly 70 percent of the population which will impose even greater food production challenges. Last year, India\'s premier economic policymaking body raised its estimate of the number of Indians living in poverty and unable to meet their nutritional needs from 28 percent to 37 percent -- representing some 440 million people. The prime minister called for the spending outlay on agriculture research and development to double or even triple by 2020 as he projected demand for food grains will grow to 280 million tons by 2020-21. The government on Saturday estimated the country\'s food grain output touched a record 241 million tonnes in the crop year that ended in June -- 23 million tonnes more than the previous crop year. India recorded bumper food grain output during 2010-11, helped by abundant monsoon rains, and is hoping for another strong monsoon this year.