9.1: Reading/Media

Rice paddy fields in southern China. Wet rice cultivation on the Yangtze delta helped transform human society from hunter-gatherers to farmers at 7,700 BP and then to urban settlers at 5,100 BP. (Photo by Gao Jialiang.)

Rice Farming on Yangtze Delta in Predynastic China, 5,100 BP

Abstract of "Fire and flood management of coastal swamp enabled first rice paddy cultivation in east China" by Y. Zong, Z. Chen, J. Innes, et al. Nature 449, 459-462 (2007).

Excerpts from "Earliest hydraulic enterprise in China, 5,100 years ago" by B. Liu, N. Wang, M. Chen, et al. Proc. Natl. Acad. Sci. U.S.A. 114 (52) 13637-13642 (2017). CC BY

Rice cultivation and the transition from hunter-gatherers to farmers

Abstract (Yong et al): The adoption of cereal cultivation was one of the most important cultural processes in history, marking the transition from hunting and gathering by Mesolithic foragers to the food-producing economy of Neolithic farmers. In the Lower Yangtze region of China, a centre of rice domestication, the timing and system of initial rice cultivation remain unclear. Here we report detailed evidence from Kuahuqiao that reveals the precise cultural and environmental context of rice cultivation at this earliest known Neolithic site in eastern China, 7,700 calibrated years before present (cal. yr BP). Pollen, algal, fungal spore and micro-charcoal data from sediments demonstrate that these Neolithic communities selected lowland swamps for their rice cultivation and settlement, using fire to clear alder-dominated wetland scrub and prepare the site for occupation, then to maintain wet grassland vegetation of paddy type. Regular flooding by slightly brackish water was probably controlled by ‘bunding’ to maintain crop yields. The site’s exploitation ceased when it was overwhelmed by marine inundation 7,550 cal. yr BP. Our results establish that rice cultivation began in coastal wetlands of eastern China, an ecosystem vulnerable to coastal change but of high fertility and productivity, attractions maximized for about two centuries by sustained high levels of cultural management of the environment.

Hydraulic-driven farming on Yangtze delta

Excerpt (Liu et al.): Here we present one of the world’s oldest examples of large-scale and formalized water management, in the case of the Liangzhu culture of the Yangtze Delta, dated at 5,300–4,300 years BP (Figure \(\PageIndex{1}\)). The Liangzhu culture represented a peak of early cultural and social development predating the historically recorded Chinese dynasties; hence, this study reveals more about the ancient origins of hydraulic engineering as a core element of social, political, and economic developments. Archaeological surveys and excavations can now portray the impressive extent and structure of dams, levees, ditches, and other landscape-transforming features, supporting the ancient city of Liangzhu, with an estimated size of about 300 ha (Figure \(\PageIndex{2}\)). The results indicate an enormous collective undertaking, with unprecedented evidence for understanding how the city, economy, and society of Liangzhu functioned and developed at such a large scale. Concurrent with the evidence of technological achievements and economic success, a unique relationship between ritual order and social power is seen in the renowned jade objects in Liangzhu elite burials, thus expanding our view beyond the practicalities of water management and rice farming.

The Liangzhu case may be considered among the many agrarian societies of Asia strongly influenced by monsoonal rainfall patterns. While the predictable monsoon rains in principle could sustain abundant wetland rice fields and other farmlands, too much dependency on such a system could prove devastating whenever the monsoon events occur earlier, later, lighter, or heavier. At the Liangzhu center and elsewhere in the world, such as South Asia and Mesopotamia, populations grew increasingly dense and socially complicated while taking advantage of the monsoonal rains, yet eventually many of these cities were rendered unsustainable and were abandoned, as evidently occurred at Liangzhu by 4,300–4,200 BP. Among the challenges for the people of Liangzhu and other Asian monsoon-region farming societies, middle-to-late Holocene aridification involved numerous short-term fluctuations of precipitation with potentially profound consequences, notably well illustrated at archaeological sites of South Asia.

Crucial for understanding the role of water management in Liangzhu at 5,300–4,300 y BP, the site was situated in a naturally watery setting of low-elevation marshlands bordering the Yangtze Delta. A steady rise in postglacial sea level reached its peak around 6,500 cal BP. As it is known today, the Yangtze Delta thereafter formed with a steady supply of marine deposits coupled with river-transported sedimentation. During the time of the Liangzhu site occupation, however, the low-lying landforms mostly were inundated, and they were habitats for hydrophilic and salt-tolerant vegetation. In the sedimentary layers beneath and predating the Liangzhu settlement, deep marine deposits of grayish clay suggest that the area was estuarine marshes before the Liangzhu period. During the archaeologically defined Liangzhu period, people made use of the hillslopes and other elevated terrain, while they transformed the swampy lowlands into an inhabited landscape of artificial mounds, walls, and other man-made features. A fuller picture of the large-scale artificial transformation now has been possible with archaeological discoveries of the ancient water-management system and farmlands. Perhaps akin to the speed and scale of construction projects in modern-day China, ancient Liangzhu emerged as a radical creation, prompting unprecedented social and economic change.

The requisite labor force (for building hydraulic dams) numbered in the thousands, thus prompting questions about how the people were recruited and how they were organized. The workers most likely were among the population residing at Liangzhu, which reached 22,900–34,350 at its peak, according to the density of archaeological features. In a rice-farming settlement such as at Liangzhu, however, most people were unavailable for construction work except for a few months per year, and some may have been unwilling or unsuitable for the labor. As a unified undertaking, the hydraulic enterprise brought benefits of supporting the rice farmlands and ability to feed the city’s population as a whole. Archaeobotanical studies have confirmed the dominant role of rice in the local diet. A storage pit of 0.06–0.07 ha at eastern Mojiaoshan contained 10,000–15,000 kg of preserved rice, and it may have held more when full. Furthermore, the paddy fields at Maoshan increased in size dramatically from less than 30–40 m² in the early phase (4,900–4,600 cal BP) to 0.1 ha or up to 0.2 ha in the later phase (4,600–4,300 cal BP). The later phase saw the application of manuring, burning, and frequent draining actions, as the region’s hydrology was becoming wetter.

With the ability to control vast reservoirs and redirect water into specifically targeted locations and at any desired time, the unprecedented Liangzhu hydraulic system profoundly affected the surrounding natural and economic landscape. It formed a 1,300-ha protective screen to the north and northwest of the city, and it influenced a total of 10,000 ha. The storage volume of the high and low reservoirs would have been about 1,498 and 5,072.4 million cubic meters, respectively, forever altering the hydrology of the surrounding landscape while rendering the water itself into a controllable commodity and symbol of power. The sprawling network of channels and canals functioned along with strategically positioned gates, piers, and other constructions in support of the rice-farming economy, transport of goods and people, trade partnerships, and other goals. The waterways allowed several economic advantages that we are just now beginning to trace.

Figure \(\PageIndex{1}\): Location of the Liangzhu culture of predynastic China at the Yangtze River delta near modern-day Shanghai. (From Liu et al. 2017.)

Figure \(\PageIndex{2}\): Ecavated hydraulic infrastructure of the Liangzhu culture. (A) structure of bank at Meirendi with standing wooden planks. (B) The pier at Bianjiashen with wooden stakes. (From Liu et al. 2017.)

Key Geologic Concepts:

River delta; wetlands; Pleistocene-Holocene climate change.

Supplemental Materials:

Newsweek: "Ancient China: Colossal Waterway System Built by 5,000-Year-Old Liangzhu Civilization Discovered by Scientists". December 4, 2017.