Answer :
When Tang rulers took power, they brought peace to the countryside and game more land to the farmers. As a result, farmers were able to make many advances. They improved irrigation and introduced new ways of growing their crops. Farmers also developed new kinds of rice, which grew well in poor soil, produced more per acre, grew faster, and were resistant to disease. These changes helped farmers grow more and more rice. China's farmers also began to grow tea, which became a popular drink. They made improvements in other crops as well. With more food available, the number of people in China greatly increased. At the same time, more people moved southward, where rice grew abundantly in the Chang Jiang valley. This led to th rise of new cities. -