the further the troops marched from the banks of the Arghandab and the network of bubbling irrigation runnels which extended the cultivation to the melon beds at the edge of the valley, the drier the land became. White grasslands blowing in the wind around Qalat e-Ghilzai slowly gave way to a rockier, hillier, more marginal landscape of quartz and shale-scrub, dotted with white opium poppies and purple thistles.
