Field investigation and laboratory analysis of 22 ancient paddy soils excavated at Chuodun site, Kunshan City, Jiangsu Province, China were carried out in 2003 to （1） understand the basic characteristics of ancient ...Field investigation and laboratory analysis of 22 ancient paddy soils excavated at Chuodun site, Kunshan City, Jiangsu Province, China were carried out in 2003 to （1） understand the basic characteristics of ancient paddy soils, （2） compare the difference of soil fertility between ancient paddy soils and recent paddy soils, and （3） inquire into mechanisms of the sustainability of paddy soil. The oldest paddy soils at Chuodun site can be dated back to Neolithic age, around 6000 aBP. These ancient fields were buried in about 1-m deep from the soil surface and their areas ranged from 0.32 to 12.9 m^2 with an average of 5.2 m^2. The paddy soils with 〉 5 000 pellets phytolith g^-1 soil were termed intensively cultivated paddy soils （ICPS） and those with 〈5000 pellets phytolith g^-1 soil were called weakly cultivated soils （WCPS）. The contents of organic carbon （OC）, and total N in the former were significantly higher than that in the latter. Ancient paddy soils had higher soil pH and C/N, total and available P, and lower contents of OC, DOC, total N, S, Cu, Fe, and available K, S, Fe, Mn, and Cu compared with recent paddy soils, which were attributed to application of chemical and manure fertilizers, pollution and acidification in recent paddy soils. The variation coefficients of OC and other nutrients in ancient paddy soils with higher PI were greater than that in ancient paddy soils with low PI, which indicated that human activities had a great impact on the spatial variability of soil nutrients. The contents of OC, total N, P and S in ancient paddy soils were higher than that in ancient moss of the same age, which indicated that planting rice during Majiabang culture period was beneficial to the accumulation of those life elements.展开更多
Asian cultivated rice(Oryza sativa)has two main subspecies,indica(O.sativa sub.indica)and japonica(O.sativa sub.japonica).Japonica rice was domesticated in the middle and lower reaches of the Yangtze River in China,wh...Asian cultivated rice(Oryza sativa)has two main subspecies,indica(O.sativa sub.indica)and japonica(O.sativa sub.japonica).Japonica rice was domesticated in the middle and lower reaches of the Yangtze River in China,while indica appeared around 4000 a BP in northern south Asia after hybridization between introduced japonica and indigenous proto-indica.When and how indica rice spread into China is still barely understood,although it is cultivated widely in southern China today.Here we report on the earliest,definite indica rice remains in China,including charred seeds,phytoliths,and ancient DNA,from the newly investigated Kongsangqiao site at an elevation of 2676 m above sea level in Tibet,along with a charcoal study that reveals the vegetation and climate during of human occupation.AMS radiocarbon dating of charred indica rice grains suggests the remains are from the 8th century(700s CE).The dominant identified charcoal fragments are Himalayan pine(Pinus wallichiana),from which a rather cold climate is inferred where indica rice could not be grown in situ,suggesting it was likely brought to the site.Both archaeological and literature records thus support that indica rice,fully domesticated in northern south Asia,had spread to the southern margin of the Tibetan Plateau via parts of the ancient Tang-Tubo Road,Tubo-Nepal Road,by at least the 8th century CE.展开更多
基金The study was funded by the National Natural Science Foundation of China(40335047).We thank Professor Xu Zhihong,the Faculty of Environmental Science,Griffith University,Australia,for revising this manuscript.
文摘Field investigation and laboratory analysis of 22 ancient paddy soils excavated at Chuodun site, Kunshan City, Jiangsu Province, China were carried out in 2003 to （1） understand the basic characteristics of ancient paddy soils, （2） compare the difference of soil fertility between ancient paddy soils and recent paddy soils, and （3） inquire into mechanisms of the sustainability of paddy soil. The oldest paddy soils at Chuodun site can be dated back to Neolithic age, around 6000 aBP. These ancient fields were buried in about 1-m deep from the soil surface and their areas ranged from 0.32 to 12.9 m^2 with an average of 5.2 m^2. The paddy soils with 〉 5 000 pellets phytolith g^-1 soil were termed intensively cultivated paddy soils （ICPS） and those with 〈5000 pellets phytolith g^-1 soil were called weakly cultivated soils （WCPS）. The contents of organic carbon （OC）, and total N in the former were significantly higher than that in the latter. Ancient paddy soils had higher soil pH and C/N, total and available P, and lower contents of OC, DOC, total N, S, Cu, Fe, and available K, S, Fe, Mn, and Cu compared with recent paddy soils, which were attributed to application of chemical and manure fertilizers, pollution and acidification in recent paddy soils. The variation coefficients of OC and other nutrients in ancient paddy soils with higher PI were greater than that in ancient paddy soils with low PI, which indicated that human activities had a great impact on the spatial variability of soil nutrients. The contents of OC, total N, P and S in ancient paddy soils were higher than that in ancient moss of the same age, which indicated that planting rice during Majiabang culture period was beneficial to the accumulation of those life elements.
基金supported by the National Natural Science Foundation of China(Grant No.41930323)the Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0601)+1 种基金the Basic Science Center for Tibetan Plateau Earth System(Grant No.41988101)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA2004010103).
文摘Asian cultivated rice(Oryza sativa)has two main subspecies,indica(O.sativa sub.indica)and japonica(O.sativa sub.japonica).Japonica rice was domesticated in the middle and lower reaches of the Yangtze River in China,while indica appeared around 4000 a BP in northern south Asia after hybridization between introduced japonica and indigenous proto-indica.When and how indica rice spread into China is still barely understood,although it is cultivated widely in southern China today.Here we report on the earliest,definite indica rice remains in China,including charred seeds,phytoliths,and ancient DNA,from the newly investigated Kongsangqiao site at an elevation of 2676 m above sea level in Tibet,along with a charcoal study that reveals the vegetation and climate during of human occupation.AMS radiocarbon dating of charred indica rice grains suggests the remains are from the 8th century(700s CE).The dominant identified charcoal fragments are Himalayan pine(Pinus wallichiana),from which a rather cold climate is inferred where indica rice could not be grown in situ,suggesting it was likely brought to the site.Both archaeological and literature records thus support that indica rice,fully domesticated in northern south Asia,had spread to the southern margin of the Tibetan Plateau via parts of the ancient Tang-Tubo Road,Tubo-Nepal Road,by at least the 8th century CE.
