DISCOVERY OF RICE PHYTOLITHS IN THE NEOLITHIC SITE AT JIAHU OF HENAN PROVINCE AND ITS SIGNIFICANCE
CHEN Baozhang ,
(Regional Development Institute of Xuzhou Normal University, Xuzhou 221009, China)
(Cultural Relic Institute of Henan Province, Zhengzou 450004, China)
(State Oceanic Administration, Qingdao 266003, China)
(Chinese Science Bulletin (40)14, July, 1995. Supported by China National Natural Science Foundation. Rec’d. Dec. 29, 1994. Scanned from English by G. Leir, ed. by Leir & B. Gordon.)
Keywords: Neolithic site at Jiahu, rice phytoliths, rice cultivation, cradle.
Neolithic rice sites play an important role in the study of the origin, evolution and propagation of cultivated rice (1). Of >100 Chinese Neolithic rice sites, 80% and all earlier ones (Hemudu & Luojiajiao, ca. 7 ka B.P.; Pengtoushan, ca. 7.5-9 ka B.P.) are in the Yangtze River area. Is there earlier, cultivated rice near the Yellow or Huai Rivers? This problem has received great attention academically. Jiahu is on the alluvial plain east of Funiu Mountain in central Henan. Based on the analysis of excavated stone and pottery, early Jiahu people may have lived mainly by agriculture (2), but cultivated type and features remain a mystery.
In recent years, phytolith analysis has found wide archaeological and Quaternary application. Many world scholars concentrate on rice phytolith study (3-5) and now rice species, even subspecies, are identified by phytolith morphological traits (5-8).
This note describes the analysis of 9 samples from earlier sediments with rice phytoliths. Morphologically, we conclude people mainly planted japonica (Oryza sativa keng Ting.).
1. Material and method
The site is east of Jiahu Village and 22 km north of Wuyang Town. Using the east section of pit T23 as example (Fig. 1), sediments are dozens to 200 cm deep and divide into 7 levels. Artifacts divide into 3 stages, corresponding to levels 4, 3C and 3B. Radiocarbon ages of level 4 are 7960±150, 7920±150 and 7561±125 B.P.; the range of their calibrated (cal) age 8942-8338 B.P. Level 3C dates 7137±128 and 7105±122 B.P.; its range (cal) 7919-7907 B.P.; level 3B is (7017±131) B.P. and cal ages are 7870, 7868 and 7801 B.P.
The nine samples analysed were collected from three levels (Fig. 1).
Fig. 1. East section of pit T23 and sampling position. 1, level 4, dark yellow silty clay, 2, level 3C, greenish grey silty clay; 3, level 3B, dark grey silty clay; 4, level 3A, grey brown clay, 5, level 2B, pale yellow clay; 6, level 2A, pale yellow silty clay, 7, modern plough horizon; 8, sampling position; 9, sample number; 10, graves; D, ditch.
Weigh 10 g sample, grind it and put it carefully into H202, and then into dilute (5-10%) HCl and boil for 10 min. Then, wash out acid with distilled water and float phytoliths with heavy liquid (spec. gravity 2.35). Prepare slides for every sample and identify them microscopically.
Three types of phytoliths belong to Oryza. They are fan-shaped, dumbbell-shaped parallel to each other along the long axes, and phytoliths from caryopses (9).
Some fan-shaped phytoliths from leaves and dumbbell-shaped phytoliths occur in the 9 samples, and many phytoliths from caryopses are in samples Jh2, Jh3, Jh6 and Jh 9 (Fig. 2).
Fig. 2. Photographs of phytoliths. a, Fan-shaped phytolith from sample Jh6, x 1000; b, d, fan-shaped phytoliths from sample Jh6, x 800; c, fan-shaped phytolith from sample Jh9, x 800; e, fan-shaped phytolith from Oryza rufipogon Griff. (produced in Dongxiang of Jiangxi Province), x 800; f, fan-shaped phytolith from sample Jh2, x 800; g, i, phytoliths in caryopses from sample Jh2, x 400; h, dumbbell phytolith from sample Jh2, x 400; j, phytolith in caryopses from sample Jh6, x 400; k, dumbbell phytolith from 0. rufipogon Griff. (produced in Jiangxi), x 400; 1, m, phytolith in caryopses of 0. sativa keng Ting (0. s. japonica) (breed: Balila), x 400.
The caryopses epidermis is almost silicified to produce special polymerized identifiable phytoliths. Watanabe described them as hollow bumps with several nipples at the edge. Based on modern rice analysis, phytolith shape from caryopses may be described as mound-shaped bumps with foamed-netted stripes and smooth edges. On their projection are double nipples (Fig. 2(1)). Nipples of cultivated japonica (0. sativa keng Ting) are blunter and smaller than 0. s. indica rice (0. sativa hsien Ting), with wild rice (0. rufipogon Griff.) traits in between. Most caryopses phytoliths are like keng rice in traits.
Sato Higekane divides modern cultivated rice (0. sativa) into O. s. indica (hsien) and 0. s. japonica (keng). Based on the study of fan-shaped phytoliths variations in modern leaves, Kuzuhara Hirdoshiet et al. said most O. s. indica is "smaller with thin round shape" (a-type, Fig. 3(b)) and most O. s. japonica is "large with thick sharp shape" (b-type, Fig. 3(c)). Sato (1990) measured many shape parameters (a, b, c, d, Fig. 3(a)) of fan-shaped phytoliths from 96 breeds, providing a discriminant 2=0.049(a+b)-0.019c+0.197d-4.792(b/a)-2.614. Differentiation results are most 0. s. indica as a type, Z < -0.5, error < 8%; most 0. s. japonica as b type, Z >0.5, error <6%; and transitional types between a and b indistinct for subspecies amount to 25%.
Fig. 3. Measurements and types of fan-shaped phytoliths. (a) Parameters: (b) a-type; (c) b-type.
To differentiate rice subspecies at Jiahu Site, we reanalysed samples Jh2, Jh3, Jh6, Jh9 (take 30 g, treat with acid and float with heavy liquid as usual, all phytoliths floated, observed and measured on slides microscopically without preparing fixed slides). More than 30 grains of trait fan-shaped phytoliths from rice were measured for every sample. Differentiation results of statistical data with Sato’s discriminant was 0. s. hsien (a-type) for 22%, 0. s. keng (b-type) for 49% and transitional type for 29%.
It can be inferred from the study on fan-shaped phytoliths and caryopses that most rice cultivated by early Jiahu people is 0. s. japonica.
Inspired by the phytolith study, many carbonized caryopses were found in samples Jh2, Jh3 and Jh6 by diffusing-sieving (Fig. 4). Most old caryopses were identified as 0. s. japonica or close by Professor Wang Xiangkun. In addition, caryopses vestiges occur in sample Jh9, most like cultivated 0. s. japonica as observed under SEM. As aforementioned, the inference from phytolith study is that most rice cultivated by early Jiahu people was O. s. japonica or similar, and further verified by carbonized caryopses and their vestiges.
Fig. 4. Carbonized caryopses from sample Jh6 in Jiahu. a, ca. x 3.5; b, ca. x 1; c, ca. x 10; d, SEM photograph, x 300
3 Discussion and significance
It is unquestionable that Jiahu rice remains are cultivated, owing to the discoveries of the phytoliths and carbonized caryopses and vestiges of caryopses in all 9 samples from all 3 earlier periods. Moreover, many farm tools like stone axes, stone shovels, bone spades, zigzag stone sickles, blades, nether millstones and stone-pestles, were excavated. Their function was felling trees, shovelling soil, and reaping and grinding rice. Therefore, it is evident early Jiahu people created a fairly developed large scale rice culture.
Jiahu rice cultivation allows at least 2000 years of tracing rice cultivation along the Yellow and Huai Rivers. It challenges the hypothesis that the lower Yangtze basins, south China or the Yunnan-Guizhou Plateau were cradles of cultivated rice.
This finding is very significant. It is not only the earliest cultivated rice along the Yellow and Huai Rivers, but among the world’s earliest. Jiahu’s first period is the same as Pengtoushan culture in Hunan Province, considered the earliest evidence of Chinese cultivated rice. Jiahu people can be considered more advanced than others in the same period, as seen in primitive script and a 7-tone bone flute. Considering palaeoclimatic edge effects, we deduce early Jiahu people planted rice earlier than Pengtoushan, and the Huai River and Jiahu may be the cradle of Chinese cultivated rice or one of the cradles.
Much needed data were lacking because little has been preserved and analysis difficult. Many farm tools were excavated in many Chinese Neolithic sites without crops, a regrettable obstacle to the study of early cultivation. Phytoliths of crops and other plants were much more easily preserved in sediments and other sites than sporopollens, and easily identified. For this reason, phytolith analysis has become an important technique in agricultural and environmental archaeology, and will play a very important role in future studies of the origin and propagation of cultivated rice.
Acknowledgment. We are indebted to Peking University, State Cultural Relic Administration and State Bureau of Seismology for radiocarbon dating; to Xue Jia and Zhou Chuyuan, Peking University, for photographic assistance; to Prof. Wang Xiangkun, Beijing Agricultural University, for providing modern rice samples, determining old rice and guidance. We would like to thank Dr. Jiang Qinhua of Peking University, Dr. Wu Naiqin and Dr. Tong Haowen of Chinese Academy of Sciences for their discussion. We are grateful to Profs. Jia Lanpo, Zhou Kunshu and Kong Zhaochen of Chinese Academy of Sciences, Profs. Yan Wenming. An Taixang, Ren Mingda and Wang Xianzeng of Peking University for their guidance and assistance.
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