What reform was made early in the Tang dynasty?

The social economy in the earlier period of the Tang Dynasty underwent a rising process of recovery, development and prosperity. In particular, under the Zhen Guan Reign and the heyday of Kaiyuan, the national economy reached an unprecedented advanced level.

Agriculture: Since the collapse of the Sui Dynasty (581 - 618), productivity had been severely damaged and the national economy was in paralysis. After the Tang Dynasty reunified the whole nation, Emperor Kao Tsu paid much attention to develop agriculture and successively implemented a series of reforms, such as Juntian Zhi (Land Equalization System), and Zuyongdiao System. In this way, the peasants' burden was lessened and production efficiency was improved. As a result, farm tools and agricultural technique were improved. In addition, many irrigation works were completed soon after the foundation of the Tang Dynasty, which contributed to the rapid development of agriculture in Zhen Guan Reign and the heyday of Kaiyuan. The economy was very great in power.