Final answer:
Chinese agriculture intensively farms the land using irrigation systems and wet rice agriculture to produce hearty crops such as grain and rice.
Step-by-step explanation:
The feature of Chinese agriculture that has resulted in the Chinese having to construct irrigation systems and intensively farm the land to produce hearty crops such as grain and rice is wet rice agriculture.
Wet rice agriculture, also known as paddy farming, involves growing rice in flooded fields. This method allows rice to thrive as it can breathe underwater and take in the necessary nutrients. The use of irrigation systems and the flooding and draining of fields at appropriate times is crucial to the success of wet rice agriculture.
Rice produces more food per acre than any other grain, making it a staple crop in China. The availability of water in southern areas, longer growing seasons, and the development of new strains of rice with shorter time to harvest also contribute to the intensive farming practices in Chinese agriculture.