Eastern Border of Achaemenid Persia.
Source:commons.wikimedia.org.Author: Ἀλέξανδρος ὁ Μέγας.
The history of southern Kazakhstan, is history of farmers paying tribute to the nomads. The area has been inhabited by land tillers for the past three thousand years. At first the areas among Syrdaria river, were inhabited by Massagheti, mostly nomadic group where some people chose to till land. As generations passed the cultures of herders and farmers became more different. The farmers of the area became connected to the Sogdiana cultural region, which was also inhabited by Iranian people. The Sogdian culture was that of farmers, merchants and artisans. The South Kazakhstan province, south of Betpak Dala, was included into that region, as well as river valleys of Uzbekistan, Tadjikistan, and Kyrgizstan. It was part of Achaemenid empire, And then of the Greek Bactrian Kingdom. Then came the long reign of Nomadic tribes from the North, various tribes and khans, fought each other, but the pattern stayed the same. The land tillers were inferior to the nomads. It did not change after locals have been converted to Islam. The change of language from Iranic to Turkic, also changed little. That continued until the Russians came. Russians did not come for tribute. They came for cotton. Their merchants bought cotton from the locals and shipped it to central Russia, where it was made into clothes, those same merchants sold to locals.
In 20th century cotton became the main crop in many districts of South Kazakhstan. Cotton production in the region expanded so much, new irrigation canals had to dug.The waters flowing to the Aral sea were diverted to thirsty cotton fields. Which led to drying of the Aral, and turned lands around former lake bed into an official environmental disaster zone.
Nevertheless, cotton is still grown in the region.