Another use for paddy fields could be sea salt extraction. By letting water evaporate on a paddy field in a beach or ocean biome.

Not sure how we would implement that.

And you should no longer grow rice on the paddy you used to obtain salt as its too salty for any crops

If the paddy is in the right biome and if no crops are planted and if watered , use the random tick of the block to increase a counter (like for saplings). when the counter reaches x, transform the paddy with a variant with a layer of salt. In fact i miss the salt made by boiling salted water from the 1.7 version of Growthcraft.

We can work with that ...