Nepal, Aug. 11 -- Until a decade ago, the paddies of Nepal's Tarai were dominated by rice varieties whose names were deeply woven into the region's farming culture: Sona Mansuli, Soni, Katarni, Savitri, Ram Dhan, Radha-4, Sawadhan and Swarna, also known as Ardinath.

By this time of year, the fields would already be green with these familiar varieties, their cultivation tied to generations of farming knowledge and the agricultural rhythms of the plains.

These were more than traditional crops. They were adapted to the Tarai's soil and climate and had long formed the backbone of farming communities in what is considered Nepal's food basket.

Today, many of these varieties are disappearing.

Across the Tarai, and particularly in Madhesh pro...