Density of soybean canopy was measured by the image analysis of color and infrared pictures taken by 35mm cameras and its applicability to the estimation of biomass of soybean canopy was examined. The measurements of the density were based on the gray level of pixels on digital image data in which the original information of the density of the canopy was non-linearly biased through several signal conversions such as photographing, videotizing, decoding of composit video signal, A/D conversion and etc. In this study, in order to compensate the bias, a multi-step gray-scale was photographed in the identical pictures with those to be analyzed for measuring the density of the soybean canopy. The gray level of the digital image was standardized so that the gray level of the steps of the gray scale in the digital image was proportional to the actual density of the steps. Then, the density of the objective canopy was calculated from the average gray level of the canopy in the standardized digital image. For an objective canopy, digital images in three different spectral bands were obtained from a color picture and a digital image in a near-infrared band was obtained from an infrared picture. Consequently density values in 4 different bands corresponding to those digital images were measured. The soybean canopies for 3 types of varieties, 3 kinds of planting density and 4 different growth stages were examined and the exponentially transformed values of the density or the functions of those showed somewhat linear relations with the soybean canopy biomass such as LAI, fresh weight, dry weight and dry leaf weight. The results were similar to those given before by the studies with spectral-meters and indicated that the procedure in this study was applicable to estimate the soybean canopy biomass.

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Although the standard growing season of pasture plants in the Konsen Area in the north-eastern part of Hokkaido occurs from April to October, it changes year by year depending on the meteorological conditions. In this study the seasonal changes in 10-day mean air-temperature monitored over a period of 62 years were divided into 7 typical patterns, for which plant growth was calculated based on a system model describing temporal changes in the pasture herbage biomass. Although long term meteorological predictions cannot be easily obtained, it may be possible to pick up one or two, as predicted pattern, out of the 7 patterns of seasonal changes in meteorological conditions, and herbage biomass can be predicted using the patterns. 1. At the Hokkaido Prefectural Konsen Agricultural Experiment Station, annual meteorological data have been accumulated for 62 years since 1928. Using the 10-day mean air temperature data collected during the period from April to October, which corresponds to the growing season of pasture plants, the 62 years were divided into 7 year groups by applying a numerical classification method (k-means). 2. A complex system model describing seasonal changes in pasture plant biomass at Nishinasuno, Central Japan, had already been developed. This Nishinasuno model was revised to fit the data obtained at the Konsen Agricultural Experiment Station. Using this new model, the seasonal changes in plant biomass were calculated for each of the 7 meteorological patterns. 3. By fitting a simple logistic growth curve to the seasonal plant biomass changes analysed above, seasonal changes in the growth coefficient, r, were estimated. Farmers and cooperatives of farmers can use this simple logistic model and the r series obtained in the above calculations instead of the complex system model. The logistic model is expressed by the equation: dx/dt = rx (1-x/K)-a, where x denotes the herbage biomass at time t, K is the carrying capacity and a the herbage consumption by cattle.

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In this paper, the structure of a nation-wide information database for vegetables and fruits, NAPASS (Nation-wide Agricultural products Price Analysis Support System) is presented and the evaluation of the system is made. The database covers the daily quantity and price data for 55 commodities of vegetables and 68 commodities of fruits from January, 1977 to December, 1990 in 77 major wholesale markets in Japan. More than 9.8 million records with 570MB volume are stored in magneto-optic (MO) disks on a UNIX workstation, and the data retrieval and the processing operation under various condition is available with an interactive program coded in FORTRAN 77. The source data for the database is originally surveyed by the Ministry of Agriculture, Forestry and Fisheries (MAFF) and stocked into monthly computer compatible magnetic tapes. Since total volume of source data is more than 5.4GB, a data compression techniques with code conversion is applied, where the data compression ratio is 10.7%. Finally the system is evaluated from the view points of response time, networking between the database and personal computer, the function of the database and portability to other OS. The results imply that the database is reasonably practical as a research support system.

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In this paper, the accuracy of the market information which is stored in NAPASS (Nation-wide Agricultural products Price Analysis Support System) is evaluated using the detailed account information of pear products of an agricultural cooperatives branch in Toyama prefecture. The daily market information of six markets from 1988 to 1990 (August and September) are compared with the detailed account information and the relations are analyzed. The results indicate that the daily quantity of market information is almost same to corresponding quantity of the detailed account information in four markets through the analyzed period. On the other hand, the daily price of market information is almost same to corresponding price of the detailed account information in two markets. In the other markets, the major types of relations between market information and the detailed account information are categorized as follows: (1) price of the market information is almost same to the price of the detailed account information in certain standard (quality and size) in a given market and month, (2) the former is likely same to the latter, (3) the relations between the former and the latter are not clear. However, at least the patterns of daily movements of the former and the latter are almost same. The above results imply that users of market information (or NAPASS) should recognize the characteristics of the daily market information. Then the market information is useful in researches on price and quantity movements, supply response, and so on.

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The use of coastal resources is expected to become more diversified and advanced in the near future, as reflected in the recent industrial and public interests toward waterfront areas. This increased use of coastal land and shallow sea area, inevitably, leads to various conflicts, such as a competition for coastal zone development and marine preservation among traditional users and new comers. To help decision makers in evaluating adequate policy issues for integrated management of sustainable resource use and environmental preservation, this paper presents a system of economic -ecological models that deal with such complexities of multiple resource use, dynamic inter-dependence of marine ecosystem, and so on. An empirical model is constructed based on the case study of Harima-Nada (eastern part of Seto Inland Sea) in such a way that combines an input-output model of coastal economy with an ecological model of marine resource in order to coordinate resource allocation and environmental pollution. The constructed model, validated by the economic-ecological data in 1985, is used to evaluate policy options in terms of regional economic growth, construction of sewege system, and preservation of natural coast.

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