1. The chemical analysis of the crude protein, ether-soluble materials, cellulose, lignin, other carbohydrates, hot- and cold-water-soluble fractions for the litter in the grasslands of P. longivalvis, R. sachalinensis and S. purpurascens were made. The decay rates of these organic constituents were compared among the grassland types, and then the organic constituents that might hold the key to the differences were examined by the theory. 2. The theoretical models used to analyze the decay rates are the equations (1), (2), (4) and (6). The models of each organic constituent for the decomposition and accumulation were shown in Table 3 and 4. 3. The decay constants of crude protein, ether-soluble materials, cellulose, lignin, other carbohydrates, hot- and cold-water-soluble fractions were 0.146, 0.412, 0.452, 0.238, 0.733, 0.333 and 0.918 in the P. longivalvis grassland, 0.235, 0.730, 0.512, 0.298, 0.868, 0.621 and 1.625 in the R. sachalinensis grassland, and 0.076, 0.324, 0.157, 0.110, 0.245, 0.272 and 0.516 in the S. purpurascens grassland, respectively. 4. The periods required to reach half ways to the asymptotic levels of decomposition and accumulation for crude protein, ether-soluble materials, cellulose, lignin, other carbohydrates, hot- and cold-water-soluble fractions of the litter were 4.74, 1.68, 1.53, 2.92, 0.95, 2.08 and 0.76 years in the P. longivalvis grassland, 2.95, 0.95, 1.35, 2.32, 0.80, 1.12 and 0.43 years in the R. sachalinensis grassland, and 9.09, 2.14, 4.41, 6.28, 2.82, 2.55 and 1.34 years in the S. purpurascens grassland, respectively. 5. The decay velocity of crude protein of the litter was the slowest of all those of the organic constituents and that of lignin was slower than those of other organic constituents except crude protein. 6. On the other hand, cold-water-soluble fractions were decomposed most rapidly of all the organic constituents and other carbohydrates more rapidly than other organic constituents except cold-water-soluble materials, while cellulose was decomposed slowlier than other carbohydrates and cold-water-soluble materials. 7. Hot-water- and ether-soluble materials had not a certain tendency but these were decomposed more rapidly than lignin and crude protein and slowlier than cold-water-soluble fractions. 8. Each decay rate of organic constituents had highly significant differences among species.

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1. This investigation is carried out to clarify the cycles of organic nitrogen under the grassland ecosystems of P. longivalvis, P. sachalinensis and S. purpurascens at the Satsunai Riverside. 2. The basic differential equation for the rate of change in nitrogen storage is [Table] illustrated by build-up and turnover of organic nitrogen, particularly in three grassland ecosystems. The equations of (9), (10), (11), (12), (13) and (14) are derived from the the basic concepts of the equations (1), (2) and (3). 3. The turnover velocity fractions of nitrogen for the P. longivalvis, R. sachalinensis and S. purpurascens grasslands were r=0.148, r=0.239 and r=0.077 respectively. 4. The times required to reach 50, 95 and 99 percent to steady state levels and turnover values of nitrogen on the grassland floors are as follows: 5. The amounts of annual cycles of nitrogen are 4.047, 6.993 and 1.528g N/m^2 in the P. longivalvis-, R. sachalinensis- and S. purpurascens grasslands respectively.

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The vegetative propagation methods of alfalfa by stem cutting using the sand rooting medium were studied and the varietal differences for rooting ability were investigated. Eight varieties used in this experiment were Du Puits, Common, Williamsburg, Moapa Grimm, Rambler, Rhizoma and Narragansett. Data were taken on the rate of living cuttings, the length of the longest root and the number of roots at two weeks after planting and on the rate of living cuttings, the diameter of the cuttings, the habit of root development and the weight of leaves at five weeks after planting in the sand rooting medium. The results are as follows ; 1) The rate of living cuttings at two weeks after planting was over 80.0% in seven varieties (Rambler, Narragansett, Du Puits, Rhizoma, Williamsburg, Grimm and Common), but only 74.0% in Moapa. 2) The rate of living cuttings at five weeks after planting was over 80.0% in five varieties (Rambler, Narragansett, Du Puits, Rhizoma and Williamsburg), but less than 80.0% in the other three varieties (Grimm, Commom and Moapa). 3) The length of the longest root was apparently longer in the two varieties (Du Puits and Rambler) as compared with the other varieties. 4) In most cases, roots initiated to develope from the cutting surface of the lower part of stem. 5) Correlation coefficient, r=0.852, was found between the weight of roots and the weight of leaves, therefore it seemed that growth of roots was closely related to the regrowth.

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It seems to be very important for the good managemhnt of sown grassland to diagnose its current condition and to estimate tne trend of changes to come. In this experiment the changes in the conditions and the trend on orchardgrass sward were studied under different cutting frequencies (3, 4 and 5 times of cutting for a year) and the different levels of fertilizer application (1, 2 and 4kg/a of NPK were applied for a year) from 1968 to 1969. The results were summarized as follows ; 1) In the plots with 3 times of cutting and 4kg/a application the number of stubbles and the basal coverage decreased gradually but the diameter of stubbles increased comparing with the other treatments and grass type became more erect comparatively. 2) In the plots with 5 times of cutting and light fertilizer application (1k/a) the number of stubbles and basal coverage were maintained but the subbles were comparatively small in size, and prostrate plants became dominant. 3) As above mentioned, by the difference of cutting frequency and the amount of fertilizers, the condition of orchardgrass sward changed into various states in a short time of two years. Number of stubbles, diameter of stubbles, basal coverage and grass type changed remarkably corresponding to the yield level of sward and the management to grassland. 4) Plant height and length of leaf blade showed high correlations with weight of standing crops, but number of tillers did'nt.

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From 1957 to 1965, the author investigated the environmental characteristics of 50 natural alpine grasslands in Tokushima Prefecture. The results of the investigation were as follows. According to the classification of the lands, all of them are woodland, and most of them are more than 500m above the sea level. Therefore, most of them are steep sloped lands with gradient of 10°〜20° at 28 locations and with gradient of 21°〜40° at 22 locations. And size of grasslands was less than 50ha. at 35, less than 100ha. at 11, and less than 200ha. at 4 locations, respectively. When the grasslands were devided according to vegetation type, the number of the locations of MT type was 37, that of the SA type was 7, that of the MT-BU type was 4, and that of the WE type was 1. As for the productivity of the MT type grasslands was greatly different according to the period and the place, namely the amount of product per 10 areas ranged from 700kg to 6, 300kg. On the other hand, the productivity of SA type grasslands was not very different according to the period and the place, the amount of product per 10 ares being 500kg to 1, 550kg. The soil in the Shikoku Mountains was volcanic ash soil which contained much humus and water, and the soil layer was thick. On the other hand, that of the grasslands in the Sanuki Mountains was collvial or residual soil made of Izumi sand rocks, and it contained small quantity of water and was easily dried, for there were many small stones and existed only a little humus in it.

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Propagated plants of a clone from "Du Puits" alfalfa were grown under two day-lengths ; short day--8hr natural daylight and long day--8hr natural light plus 8hr artificial light, and four temperature regimes; day 30°-night 25°, 25-20°, 20-15℃, and 15-10°, before or after cutting to observe the effects of these treatments on the regrowth process. 1) At the initial or first harvest when the pre-treatment was finished, the yield of herbage was greater at higher temperatures as the following order 25-20°>30-25°>20-15°>15-10℃. The yield of the second and third harvest, however, increased as the pretreatment temperature was lowered. Dry matter production of whole plant during the experiment period also increased with decrease of temperature. This seems to be caused by higher rate of photosynthesis based on greater total leaf area per plant resulting from higher rate of leaf expansion with a greater leaf size and darker green color in the plant pre-treated with lower temperatures. 2) Regarding with the effects of daylength and temperature during the regrowth period, the herbage production was greater under short day compared to that under long day, and the dry weight of roots increased with decrease of temperature and day length. Under long day and higher temperatures, the tops grew more, but under short day and lower temperatures, the roots grew more than the roots or the tops, respectively. The size of leaves formed after cutting, was greatest at 20-15° under long day and at 25-20° under short day, respectively, being decreased at higher or lower temperatures.

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This investigation was conducted to clarify the daytime behavior of grazing cattle herd on the pasture, particularly of the resting form, as a part of analysis of pasture ecosystem. Holstein and Aberdeen Angus breed were used for this investigation. To analyze the resting form of grazing cattle herd, we defined resting ratio and laying ratio as follows: Resting ratio (%)=<resting cattle numbers>/<total grazing cattle numbers>×100 Lying ratio (%)=<lying-down cattle numbers>/<resting cattle numbers>×100 1) According to the investigation of seasonal variation, the highest resting ratio was shown in midsummer, followed by spring and fall. On the other hand, lying ratio showed the lowest value in midsummer. 2) It was recognized that lying ratio showed a tendency to decrease as the environmental temperature was getting higher. 3) With appearance and activating of parasitic insects, especially of horseflies, lying ratio decreased remarkablly and there was recognized a significant negative correlation between activity of parasitic insects and lying ratio. 4) A significant negative correlation was recognized between daily gain of body weight and resting ratio, while a significant positive correlation was recognized between daily gain and lying ratio. In these facts, the author disccused on the relationships between resting form of grazing cattle herd and environmental conditions. 5) From the results described above, the author classified the resting form of grazing cattle herd into five types according to the environmental conditions.

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