Very theoretical and high and lofty thought. Did it occur to you that not many people live around these barren lands (think of Thar desert??) and have you even spared thought for who will set up infrastructure there and from there upto nearest livable cities/ports/airports? And since these are export zones how would the companies send their exports? Agriculture of course needs to be taken care of as it is vital but to say only take non cultivable land will ensure that states with high degree of fertility in soil, e.g. UP , Bihar and WB would remain out of industrial growth forever. Think about it.
