Terraces are fields with strip terraces or wavy cross-sections built along the contour direction on hilly slopes.
They are an effective measure for controlling soil erosion on sloping land, and they have significant benefits in terms of water storage, soil preservation, and increased yields. Terraced fields provide better ventilation and light permeability, creating favorable conditions for crop growth and nutrient accumulation.
There are different types of terraces based on the slope of the field surface: horizontal terraces, sloping terraces, and compound terraces.
The width of terraces depends on factors such as the ground slope, soil thickness, cultivation methods, labor, and economic conditions, and is planned in coordination with irrigation and drainage systems and access roads. When constructing terraces, it is advisable to preserve the topsoil.
After the terraces are built, agricultural practices such as deep tilling, increased application of organic fertilizers, and planting appropriate pioneer crops are employed to expedite soil maturation and improve fertility. The earliest terraces in China likely appeared during the Qin and Han dynasties, primarily in the mountainous regions south of the Yangtze River, with Guangxi and Yunnan being the most prevalent.
These areas, characterized by abundant rainfall and mountainous terrain, provided suitable conditions for terrace construction. Notable examples include Liaojuan Mountain in Yunnan and the Longji Terraces in Longsheng, Guangxi.
The majority of terraces are used for rice cultivation, which requires ample water. However, ancient terraces did not rely on artificial irrigation methods due to the absence of pumps and machinery.
Instead, they relied on natural irrigation, primarily rainwater. The construction of terraces in suitable hillside locations with abundant rainfall and the provision of water storage facilities were essential to ensure sufficient water supply for rice growth. The ancient wisdom behind these practices is truly remarkable.
Additionally, ancient techniques involved digging canals and building reservoirs to divert water for irrigation. With the advancement of modern irrigation technology, if rainfall is insufficient, ditches can be dug around the terraces or reservoirs can be directly constructed.
These methods utilize mountain conditions to divert mountain springs, stored rainwater, or reservoir water for irrigation. Based on terrace planting and management experience, digging ditches is considered the most effective irrigation method as they connect the mountains and provide convenient irrigation in all directions.
In some cases, people also use cement pipes to bring water from nearby reservoirs and rivers for irrigation. Water towers are constructed at higher elevations to address the challenges of terraced irrigation. These modern irrigation practices have greatly alleviated concerns about water supply, eliminating many worries associated with irrigation.
With the ongoing social and economic development, modern irrigation techniques have reduced the labor-intensive nature of terraced farming. Modern irrigation equipment allows for a timely water supply to meet the needs of rice and other crops.
Drip irrigation technology has also emerged, providing targeted irrigation and benefiting the growth of crops. As a result, mountains are no longer limited to rice cultivation, and planting other crops can be equally successful with the use of sprinkler and drip irrigation technology.
