Nether crops are a nifty and easy to automate way to get soul sand, glowstone and nether quartz! Grow the crops near lava in the nether and watch them flourish with precious materials! Find them growing nearby lava sources in the nether, harvest them and plant them wherever you want (even in the surface)!
Remember you need to plant them on tilled netherrack! And to till it you'll need a hoe made of diamond or gold :)