Twenty years have passed since the Japanese Agricultural Systems Society (JASS) was established. It is really a matter of mutual congratulation. I want to be pleased with this 20th anniversary from heart with members. This paper is the beginning lecture of the 20th anniversary convention of the establishment. Since it was such an opportunity, the circumstances of the establishment of JASS seldom introduced are stated to a center. It starts to explain International Institute for Applied Systems Analysis (IIASA), which has an inseparable relation to the establishment of JASS. First, the research environment of IIASA is described as dispatch of Japanese researchers to Food and Agriculture Program (FAP) of IIASA. Then, it describes activities in the Japanese IIASA committee, where the establishment plan for JASS was produced. Such a Japanese IIASA committee became an establishment preparation committee of the society, starting in autumn of 1983, and JASS was established in April, 1984. The society was established within the short period of establishment preparation which is not filled in half a year. A short comment is added from recognition that it is finally coming at the time to consider the research field of the science of agricultural systems. First, the characteristic of the science of agricultural systems is described. Then, if a research field is examined referring to the presented paper by today, it will be divided roughly into technology, management and environment. Moreover, on the other hand, it is emphasized that the science of agricultural systems is one of the most important scientific fields about the "global environment issues" human-beings are facing today. Finally, it describes that the science of agricultural systems has deep relevance with Land Use/Cover Change (LUCC) which is one of the global environment issues.
Sustainable agriculture has been widely discussed as key elements to determine the future of food and environment in both developed and developing countries, while sustainable agriculture is defined as the alternation of agricultural system from the conventional agriculture with high-inputs to the one of ecologically sound, economically feasible and socially acceptable. Since the 1970s, agriculture in most of the developed countries such as EU, the USA and Japan has changed to a more intensive type with greater chemical inputs per unit of farmland. As a result, agriculture has caused various negative impacts on natural environments and those on food safety for human beings. Food safety issues are also considered closely related to the deterioration of agricultural resources such as soil and water. Paddy rice farming in Japan, under the Asian monsoon climatic conditions, has been continued and sustained for many centuries without jeopardizing natural resources. In other words, paddy rice farming in Japan has been extremely sustainable, which has maintained the high yield level of rice production for a long time. In recent decades, however, Japanese agriculture in general has also changed drastically to affect various negative impacts on natural resource conditions, due mainly to sharply increased use of chemical inputs or highly intensive nature of livestock operations. In order to improve these negative impacts from agriculture, the government of Japan has started to implement sustainable agricultural policies since 1993 by assisting farmers to adopt environmentally friendly technologies. Soil and water conservation and recycling of organic materials have also been encouraged with the partnership of general citizens (NPOs) and local industries.
Animal itself and the industry are complicated systems, because they are composed of many segments and components. In this study, systems-analysis techniques were applied to the following three subjects of animal husbandry. (1) As livestock production in Japan has become more intensive, livestock wastes tend to cause serious environmental problems. Nitrogen (N), phosphorus (P), and potassium (K) flows in livestock farms were estimated to obtain fundamental data for solving these problems. Simulation of N, P, and K flow models in dairy farms showed that the higher the milk production performance of cow is, the lower the N surplus per kg milk is. This result indicates that enhancement of milk production contributes to the reduction of environmental loss of nutrients. Life cycle assessment (LCA) was used to assess all the environmental impacts on livestock management, feed production, applied chemical fertilizer production, and manure management. Imported feed, such as corn and barley, showed higher global warming impact and acidification impact than self-supplied feed and by-product feed. (2) Three types of production models were characterized and compared; growth curve models, ad libitum feeding and growth models, and system simulation models. The growth curve models are the most simple ones which represent a relationship between age and weight and the animal is considered a black box with only output. The ad libitum feeding and growth models involve feed intake as well as weight and the animal is considered a black box with input and output. In the system simulation models, the animal is regarded as a white box of which internal relationships are known. In general, system simulation models have been developed based on popular energy systems and some of them permit us to estimate body and carcass composition and extend to bio-economic models by taking account economic variables. In this review, the historical perspective of the modeling effort and application of a bio-economic model for beef cattle production systems were illustrated. (3) It is important to improve animal performance of total population itself because of long generation interval, high value of an animal and low reproducibility. Optimization of a breeding system including performance test, selection method, production system and so on is essential. Here, the rate of genetic gain of the Japanese Brown Cattle population were compared between the station system and the field system for progeny test. It was the field system that was effective for improvement of carcass traits which had been considered to be difficult. A more efficient breeding system for the beef cattle has been perusing to optimize another factors. As described here, systems analysis is an effective tool to resolve complicated problems in animal industry and will play an important role in the future more and more.
Recently, biotelemetry for aquatic animals has become popular technique to measure their ecological and environmental data with the advance of microelectronics technologies. Especially combination of large scale integrated circuits and large memory devices has made us to measure more various and larger data than we used before. We are performing biotelemetry studies to measure ecology of several aquatic animals. In this paper, I introduce preliminary results of field studies on sea turtles, Mekong giant catfish and dugongs in Thailand.
“Periods for Integrated Study” has been introduced to the elemental school in Japan since 2002 by Ministry of Education, Culture, Sports, Science and Technology. The environmental education was adopted as the part of this class in some schools. We developed the supporting system for the environmental education in the elementary school. The objectives of this system are to support the direct experience (observation) in the natural field and to support the indirect experience (class room session). This system has the aspect of geographic information system (GIS) by means of attaching the positional information to the observation notes and photos made at the natural field. This system consists of some parts listed as follows; 1) The appropriate information is displayed on the personal data assistance (PDA) at the spatial location to encourage the observation in the natural field (teaching materials display system) and making the observation note easily at the natural field (observation note making system). 2) All observation notes and photo images created at the natural field are browsed by classmates and every student shares the information in the class room (information shearing system). 3) Every student creates HTML documents using observation notes and photo images which have the positional information (teaching materials creating system). The distinctive features of this system are 1) students can create the observation notes attached the positional information freely, 2) these observation notes are easily utilized as the GIS data, because these observation notes has the positional information, 3) appropriate information which accumulated the previous lesson can display the special location in the natural field, so these information lead to student’s attention to the objects and encourage to the observation in the special points.
Remote sensing ecology is a new paradigm fusing improved satellite remote sensing technology and ecological process study using system models. Satellite remote sensing has made a dramatic progress during nearly half a century of the history. The technology was promoted according with surrounding environment such as sensor development, renovation of computer science and the spread of Geographical Information System (GIS) software and Global Positioning System (GPS). Especially it shows outstanding results in earth environment research and timely collection of wide area agricultural information. However, this technology could not apply for elucidation of matter dynamics and eco-physiological actions occurring in a local ecosystem. On the other hand, the ecological process study, which can measure precise function and minute matter dynamics in vegetation at the target point, but it is difficult to expand environmental scale. Therefore, it makes difficult to combine remote sensing technology and ecological studies which make possible for the inclusive solution. Entering the 21 st century, improvements in spatial, spectral and temporal resolution of satellite sensor permitted not only higher accuracy of land-cover classification, but also measurement of eco-physiological functions and chase of matter dynamics in the ecosystem. Here, we propose “remote sensing ecology” which permits to apply remote sensing technology and ecological process study to observe on a same target with same spatial scale, using system models, and illustrated with some new research.
The productivity of the semiarid grasslands in Inner Mongolia, China has been decreasing rapidly due to the vegetation degradation. Using vegetation as an index, this research analyzed the changes in the characteristics of the vegetation community along a profile from inhabitants to protected non-grazing areas, and evaluated the affects of grazing to the grasslands. With an increase in grazing intensity, the dominance of Aneurolepidium chinensis and Stapa grandis in primary communities have decreased, while the dominance of Artemisia frigida and Potentilla acaulis have increased. With the increase in grazing intensity, physical properties of surface soil changed, i.e., the soil hardness and capacity increased, and the soil porosity decreased. Such changes can be used as an index to evaluate grassland degradation. The growth and development of vegetation communities depend on their biological characters and environmental conditions. The height of plant and the biomass in a vegetation community decreased with the increase in grazing intensity, while the composition of the community remained unchanged. Effects on synusias depend on grazing intensities. In the sub-shrub synusia composed of diverse species, Artemisia frigida was the most grazing-resistant. In terms of the moisture ecological type of vegetation, arid-growth species dominated in the community, communities and were complemented by mid arid-growth type of vegetation according to grazing intensity. The mid-growth and arid mid-growth types of vegetation were affected by grazing intensity, i.e., an increase in grazing intensity caused decreases in the biomass and diversity of mid-growth and arid mid-growth types of diverse vegetation.
As soil is the largest pool of carbon storage in the terrene, it is important to measure the amount of storage of soil carbon in each ecosystem. But there exist many difficulties, because it needs both data of bulk density and carbon content at each soil layer. A simple survey method of soil carbon storage is proposed based on the characterized soil horizon, is "characterized soil horizon survey method". The new method is developed using the results obtained in the previous study. It was done by the precise field investigation method of soil carbon storage with 100 plots in the 1-ha experimental cool-temperate forest ecosystem. The characterized soil horizon reflects the soil nature, which lies at a specific depth of soil layers. To estimate carbon storage in the whole soil layers, 50-60 cm layer was selected by the stepwise multiple regression analysis, which contributed 77.2% of accuracy. The equation obtained by the characterized soil horizon survey method was:
y= 5.298a + 1670.839
where, y is total carbon storage in whole soil layers (kgC/ha), and a is carbon storage in 50-60 cm layer (kgC/ha). In the validation test, soil profile samples at 50-60 cm layers taken at random 20 points were enough to estimate the remaining 80 points with the accuracy of 76.7%. To decide the characterized soil horizon in the whole study area, it requires much information at many points of the areas. So the improved soil sampler puts teeth in the new survey method, which can collect soil samples just in the original field state. As the new method combined with soil sampler can reduce time and labors comparing the existing digging method, it could substitute the existing method, contribute to the standardization of soil survey and become a powerful tool for the comparison obtained by other methods such as model and remote sensing.
To investigate the effect of artificial nitrogen load on soil respiration, the experiment was carried out in a cool-temperate forest in Japan. Three experimental sites, which consists of a coniferous forest, a broad-leaved deciduous forest with Sasa community and a broad-leaved deciduous forests without Sasa community, were established in the cool-temperate forest. We loaded 0 kg N ha-1 yr-1, 20 kg N ha-1 yr-1 and 40 kg N ha-1 yr-1 as NO3NH4 in each experimental site. The treatment of nitrogen load was started from 1999 to 2001, and soil respiration rates were measured in 2000 and 2001 using the closed chamber method. Soil respiration rates showed clear seasonal changes in both years of 2000 and 2001, irrespective of the amount of nitrogen load. The soil respiration rates in 20 kg N load treatment were higher than those in 0 kg N load in 2000 in all experimental sites. On the contrary, in 2001, the soil respiration rates in 0 kg N load were higher than those in 20 kg N load in both of the broad-leaved experimental sites, although the soil respiration in the coniferous site showed the same result as in 2000. Moreover, developing a statistical model based on the relationships between soil respiration and soil temperature, we compared temperature sensitivities obtained from each experimental site. Temperature sensitivities obtained from 20 kg N load site had a largest sensitivities in all experimental forests, whereas that from 0 kg N load site had a smallest sensitivities. These facts suggests that temperature sensitivities of soil respiration might become stronger by the nitrogen load treatment. In addition, considering global environmental issues which are both of global warming and increase in nitrogen deposition, we compared the differences in soil respiration among the experimental sites. The amount of soil respiration increased in 33%-47% when soil temperature was raised by 3 ℃ than the present condition. The effects of the global environmental issues on soil respiration were different among vegetation types and nitrogen load treatments.
In order to develop a distribution model of food resources in a local level, material flow on food industry, which used original weight, nitrogen-base and carbon-base as index, was investigated. Flowing quantity was estimated based on official statistics and survey data so that everyone can construct a flow model easily. This study focused on material flow of Ibaraki prefecture in the year 1990 and 1995. The results showed that there were three features, which were associated with food self-supporting ratio, food wastes and food service industry. Food self-supporting ratio with original weight was about 24% in 1990, but decreased to about 14% in 1995. The discharge of food wastes hardly changed during five years, but about 30% of food consumed in Ibaraki prefecture were thrown away as food wastes. Therefore, it is necessary to tackle the problem against reduction of the food wastes. The growth rate of the quantity of food distribution into the food service industry was high compared with food manufacturing industry and food distribution industry, suggesting a promotion of eating out. The material flow model developed by this study made clear the flow of food resources in a local level. It is possible for everyone to make easily this material flow model, because this model is made basically by official statistics. In addition, this material flow model is effective as a model analyzing a local area.