○Research Subject and Objectives
Aim of research
The main goal of our project is to study the history of the relationship between agriculture and environment over a period of ten thousand years. In four different climatic zones that existed in and around Eurasia in the last ten thousand years, we try to assess how the origins and development of agriculture influenced the surrounding environment. We also seek to evaluate how the environment in turn impacted on agriculture, focusing on periods of social crisis caused by the collapse of agricultural production and consequent recovery. The four climatic zones are ‘monsoon’, ‘pasture (in Europe)’, ‘desert’ and ‘vegeculture’ (Figure 1). Based on historical evidence, we focus on swidden agriculture, often criticized as having destructive effects on the environment. We evaluate the sustainability of agriculture by analyzing its history and its influence on the global environment.
Although agriculture is one of the central issues of global environmental problems, there are still many misunderstandings and lack of knowledge concerning its history, especially about its interactions with the ecosystems in which it operates. Great danger may lie ahead if we ignore this problem and continue with blind faith in the sustainability of agriculture in the future. The goal of our project is to clarify the history of relationships between agriculture and environment, focusing on periods of social collapse caused by food production failure, and to explore the means by which people survived those critical situations. We will demonstrate the mechanism of recovery of the society along chronological order. Based on these results, we hope to establish a ‘general principle of collapse and recovery’ through case studies in on the four different climatic zones.
○Progress and Results in 2018
Our aim has been to verify the hypothesis that agriculture in different parts of Eurasia did not develop continuously without setbacks. We believe that this has been achieved. In the current fiscal year, we tried to reinterpret the historical evolution of agriculture, focusing on the ‘maintenance of (especially genetic) diversity’, which is the basic concept in our project. It has been traditionally believed that since the beginning of agriculture, the genetic diversity of crop decreased, thus causing various environmental problems and natural disasters. However, not only concrete data to verify that has hardly been academically presented, but also the genetic diversity has not just decreased but shown more dynamic transformation through the history. Therefore, we aimed to collect concrete data concerning changes of genetic diversity in different fields of research.
(1) Monsoon Zone Group
(a) We conducted morphological and molecular genetic analyses of indigenous wild and cultivated rice crops from Australia and from the region between Southeast Asia and Japan (space-axis analysis). The results showed a decrease in the variety of cultivated crops, which indicates that in Monsoon cultivation, people utilized genetic diversity effectively to extend their fields. Also, the diversity of rice crops in Japan (seed size corresponds to genetic variance) increased until the Meiji Period but decreased afterwards (time-axis analysis), demonstrating that social elements and people’s taste were reflected in the choice.
(b) Research was conducted on the soil strata in Ikeshima Fukumanji site (Yao City, Osaka Prefecture) and in Maekawa site (Inakadate Village, Aomori Prefecture) (time-axis analysis). Based on the results of phytolith analysis, it was known that in both sites people had attempted to adapt to environmental changes such as flooding by introducing various crops.
(c) By examining old maps and pictures, it became clear that flooding occurred frequently in the Ikeshima Fukumanji site from the Yayoi Period to the modern era. Especially between the Middle Ages and the modern era, the cutting down of pine trees around Ikoma Mountains, where the source of the Yamato River is located, seems to have caused frequent flooding.
As the result, it was found out that monsoon zone agriculture was not constantly developed through the history as previously discussed, but has gone through a number of collapse and recoveries using various shinogi (=adaptation) techniques.
(2) Mugi Zone Group
(a) We conducted pollen analyses on samples collected at two different locations of Xinjiang Uygur Autonomous Region. From the analysis of the mud-like substance coating the coffins of Xiaohe Tombs, we found the following: in the BM Period (3500-3400 years ago), there were no forests in the region but water was abundant and some types of grain were being cultivated. In the following M Period (3400-3200 years ago) the region became drier and more saline. The length and weight of wheat grains excavated from coffins show constant increase from the BM to M periods, but in the end of the M period both length and weight become varied, indicating unstable wheat production. This also shows degradation of environment from the BM to M periods. Results of pollen analysis of a soil boring sample near Rouqiang (80-100cm depth, age unknown) showed that there were no major environmental changes and that semi-shrub deserts, as can be seen today, have existed over a long period. From these results, it was assumed that human activities, especially agriculture, caused environmental changes such as desertification in this region. The need for more detailed and larger-scale analyses was also acknowledged.
(b) A cultivation experiment was conducted over 3 years in the dry region of West Asia in several regions, in order to assess the water consumption rate of different types of wheat. Rain-fed cultivation of bread wheat, Durum wheat, Emmer wheat and Einkorn wheat showed that the later the flowering season was, the lower the crop yield became. Einkorn wheat, whose flowering season was the last, hardly yielded at all. Thus we learned that the productivity difference depended largely on environmental issues such as water and temperature during the reproductive stage.
Through the archaeological research of the Xiaohe Tomb site and experimental studies, it was verified that the Xiaohe Tomb area used to have rather rich vegetation and fauna, which enabled pasturage and cultivation of particularly water-requiring bread wheat. With the research result, our original assumption of the project: desertification (=environmental degradation) was caused by human activities rather than natural causes, was verified on concrete data. Further studies on destructive factors created by human activities, such as salinization, will be done in the final year of the project to complete the research.
(3) Vegeculture Zone Group
(a) In the Philippines, we conducted research on the origins of taro cultivation. It is believed that agriculture was introduced to the Philippines from south China and Taiwan. However, when we examined the diffusion of modern taro crops and their usage, we discovered wild and cultivated varieties that have not been reported previously. Also, a semi-wild variety seems to be widely diffused and is utilized in daily life. This suggests that the cultivation of taro began in the Philippines.
(b) Ethnographic research on tuber crop cultivation was conducted in the Eastern Highlands of Papua New Guinea, focusing on the diversity of cultivation. We learned that various types of yam and taro are being utilized and that they are used on different occasions, depending on their function and importance. People are encouraged to cultivate different types of sweet potato and no agricultural methods exist to cultivate high-value varieties intensively.
(4) Slash-and-burn Agriculture Group
(a) We began to analyze historical records concerning land usage from the former Hakumine Village (current Hakumine, Hakusan City), Ishikawa Prefecture, which date from the entire Edo Period (Echizen kaga hakusan jûhachikamura toritsugi-moto Yamagishi Jûrôemon-ke monjo, etc.). In this document, there are many sale agreement papers of land where slash-and-burn agriculture was practised. They are therefore important materials to learn about the reality of this technique, whose yield was usually not included in the official annual rice yield (add: accounts or figures?). The document is currently being examined, while at the same time study is being conducted on the changes of crops cultivated.
(b) The Third Slash-and-burn Agriculture Summit took place in Oita City. We demonstrated the importance of our research in connection to contemporary agricultural issues in Japan, especially in relation to the problems of intermediate and mountainous areas.
Connection with final results
As the above-mentioned research report on taro cultivation demonstrates, there is still a strong possibility that our understanding of the historical evolution of agriculture may change further in the future. The ultimate goal of our project is to fundamentally rewrite the history of relationships between agriculture and environment and to make suggestions concerning the future of agriculture. We are confident of having made a large step towards achieving our goal, through the different achievements of this year and the establishment of contacts with researchers in a range of regions and fields at different symposia. We were also able to publish four volumes of the ‘Agricultural History in Eurasian Continent’ (5 vol.), the last volume of which will appear during the current fiscal year.
Some parts of our achievements were broadcast in the NHK program ‘Science ZERO’. The research report from the Tian-luo-shan site in Zhejiang Province was published as the project member’s achievement in Science journal. Also, an article written by one of the project members appeared in the last year’s Nature Genetics journal. He currently leads international discussion about early agriculture in Monsoon Asia.
■Monsoon Zone Group
■Mugi Zone Group
■Swidden Agriculture Group
■Vegeculture Zone Group
■v) Research Results Promotion Group
Problems we faced during the current fiscal year and suggested solutions:
Since the next fiscal year will be the last year of our project, we do not plan to perform any large-scale research abroad. However, since we could not conduct research in Xinjiang Uygur Autonomous Region this year, we hope to undertake it next year, if the local situation permits, even if only to a limited extent.
Issues for next fiscal year:
1) We will try to determine the factors that, after natural disasters, either allowed the continuation of agricultural activity or caused its collapse, while focusing on people’s occupation, type of disaster and power structure of each period. From this, we will establish a general principle that could inspire future agricultural activity.
2) In the process of (1), we will make use of photographs taken by Sven Hedin, in order to learn about paleoenvironmental change in the Xinjiang Uygur Autonomous Region. We will digitize these photographs and create a database to preserve them as cultural heritage.
3) Weeds, harmful insects and disease-causing organisms appeared when agricultural activity first began. These are more or less uniform beings, selected to survive in a homogeneous agricultural field. They have been eliminated by the use of chemical substances (pesticides), which also have the effect of harming or destroying the environment. The Slash-and-burn Agriculture Group, on the other hand, demonstrated that fire not only prevented the increase of weeds, harmful insects and disease-causing organisms, but also caused chemical substances, which plants could use, to increase in the soil. We plan to organize a symposium entitled ‘Weeds, harmful insects and disease-causing germs’.
4) We will publish our achievements, which have been made public this year in the form of publications and symposia, also in English (we will also prepare a book in English). Our short-term goal is to successfully organize an exhibition at the National Museum of Nature and Science (September to November 2010), which is planned as part of our final project report. We also plan to produce a scientific publication on the domestication of plants and animals. Since agriculture is a theme closely related to our everyday life, we have organized the ‘Seminar on environmental thoughts’ more than twenty five times now. These results will also be published in book form.
5) Different knowledge related to life culture, such as agriculture and food, will largely contribute to making concrete suggestions in RIHN’s basic fields of research, whose ultimate goal is to identify advantageous ways of future human life. Therefore we hope to transfer our knowledge, based on the achievements of our project, to other projects. In this way, the research quality of the whole institute will benefit.