Research On Farmland Management Technology In The Late Longshan Period In North Region Of Shanxi Province

Farmland management techniques are one of the important ways to improve crop yields and are closely related to the original accumulation of agriculture.With the development of history,fertilization and other farmland management techniques have become more and more common in the process of agricultural development,which not only solved the problem of human sustenance,but also laid the material foundation for the development of complex society.However,domestic research of ancient farmland management techniques is still lacking,and more information is needed to supplement and improve them.The archaeological data in north region of Shanxi province,which is at the junction of traditional Chinese farming culture and nomadic culture,is of high research value.In this paper,carbon and nitrogen stable isotope tests and analyses were carried out on 10 cases of charred Setaria italica,10 cases of charred Panicum miliaceum,1 case of Chenopodium album sp.and 1 case of Corispermum excavated from the Jijiazhuang site and 11 cases of charred Setaria italica and 4 cases of charred Panicum miliaceum excavated from the Xinzhang site during the Late Longshan period in north region of Shanxi province.And the remains of carbonized plants excavated from the relevant sites were also selected for comparative analysis in order to understand the development of farm management techniques in different spatial and temporal contexts.The carbon and nitrogen stable isotope results show that the charred Setaria italica（-9.8‰～-9.2‰,-9.5‰±0.2‰,4.2‰～7.0‰,5.2‰±0.9‰,n=10）is higher than the values of charred Panicum miliaceum（-10.4‰～-9.5‰,-10.0‰±0.3‰,3.1‰～6.0‰,5.0‰±0.8‰,n=10）)at the late Longshan period in north region of Shanxi province.Theδ¹³C values of Chenopodium album sp.（-24.8‰,4.3‰,n=1）and Corispermum（-24.4‰,6.0‰,n=1）are also consistent with typical C₃plants characteristics.The distribution range ofδ¹³C andδ¹⁵N values of charred Setaria italica（-9.7‰～-8.8‰,-9.3‰±0.3‰,3.9‰～7.1‰,5.4‰±1.0‰,n=11）and Panicum miliaceum（-10.0‰～-9.3‰,-9.7‰±0.4‰,2.5‰～5.8‰,4.4‰±1.4‰,n=4）excavated from the Xinzhang site is close to that of Jijiazhuang site.The distribution ofδ¹³C values of charred Setaria italica and Panicum miliaceum is more concentrated relative toδ¹⁵N values at both sites,and the meanδ¹³C values of charred Setaria italica are higher than the charred Panicum miliaceum,which may be due to the different characteristics of foxtail millet and broomcorn millet.The distribution ofδ¹³C values of charred foxtail millet and broomcorn millet at both sites is consistent with the range of values for C₄plants,but due to the lack of a systematic model of the relationship betweenδ¹³C values and water for C₄plants,it is not possible to accurately infer whether the ancestors in north region of Shanxi province had ever managed the crops with irrigation in the late Longshan period.From theδ¹⁵N values,theδ¹⁵N values of charred millets excavated from the two sites in north region of Shanxi province are higher than the environmental benchmark values.Drawing on the fertilization model for wheat crops delineated by Boggard et al,it indicates that the ancestors had begun to manage the crops with long-term fertilization in the late Longshan period,and most of the samples are at the level of moderate and high fertilization.In addition,smaller standard deviation of theδ¹⁵N values for charred millets in the north region of Shanxi province,indicating that the fertilization management experienced by crops is relatively similar and uniform.Compared with the standard deviation of theδ¹⁵N values of charred millet in other sites of the same period,the standard deviation of foxtail millet and broomcorn millet in the north region of Shanxi province is of the same size,indicating that the ancestors did not differentiate in the fertilization management of crops.