Question

what are the advantages and disadvantages of using high yielding varieties of crops

Answer 1

High yielding varieties demand high inputs to sustain them (a disadvantage)

Key to this is plentiful water and a suitable soil medium for the crop grown. If you can't supply either of these two there is no point applying fertilisers and minerals to the soil to aid a yield which isn't potentially possible.

So in a medium/low rainfall area you want varieties with a high drought resistance rather than yield. Examples American mid west or lots of Australia. These areas will put much less inputs on than a high rainfall area as the crop will have a lower yield potential and demand less.

Obviously the advantage of high yielding varieties are higher yield potential (potential profit).