The introduction of transplantation around the sixth century BCE dramatically increased the production of which crop?

Paddy

During the sixth century BCE, a significant strategy to enhance agricultural production involved the adoption of plough agriculture, particularly in fertile alluvial river valleys such as those of the Ganga and the Kaveri. The iron-tipped ploughshare proved instrumental in turning the alluvial soil, especially in regions with abundant rainfall. The introduction of transplantation techniques further boosted paddy production in some parts of the Ganga valley, although it entailed strenuous labor for the cultivators.