Consider the following statements distinguishing permaculture farming from conventional chemical farming:

1. Permaculture discourages monoculture, a practice that conventional chemical farming favours.

2. Permaculture relies heavily on mulching and avoids the soil-salinity build-up associated with conventional chemical inputs.

3. Permaculture is generally harder to practise in semi-arid or dry regions than conventional chemical farming.

How many of the statements given above are correct?