Answer:
it is because it has plain, fertile land with alluvial soil and plenty of water for irrigation and agriculture.
Step-by-step explanation:
Terai region lies in the southern part of Nepal. It covers an area of 25,020 sq. km making about 17% of the total area of the country. It is called the 'Granary of Nepal' because it has plain, fertile land with alluvial soil and plenty of water for irrigation and agriculture.