This trial was carried out to clarify the composition and the rate of disappearance of neutral detergent fiber of the stem and sheath, and the leaf of soiling sorgo forage and Italian ryegrass hay by the in vivo and the in vitro method. The results obtained were summarized as follows. 1. There were little differences in neutral detergent fiber (NDF) contents of the three forages, but the apparent digestibilities of NDF of the stem and sheath, the leaf of sorgo forage and Italian ryegrass hay were 51.7%, 67.9% and 82.0%, respectively. Therefore, the apparent digestibility of cell contents of Italian ryegrass hay was very low, and lower than that of the stem and sheath of sorgo forage. If the digestibilities of cell contents of the three forages were all 98%, the digestibilities of NDF of the stem and sheath, the leaf of sorgo forage and Italian ryegrass. hay were 36%, 46% and 58%, respectively. 2. There was an increase in NDF, ADF and lignin content of the stem and sheath, and the leaf with growing, except NDF content of the leaf almost remained constant. 3. After 60 hours in the rumen, the rates of disappearance of dry matter of the three forages coincided with each dry matter digestibilities by the total feces collection method. But the rates of disappearance of dry matter of the three were nearly equal to those of each NDF, therefore, those of NDF were very different from the digestibilities of NDF by the total feces collection method. 4. The rate of disappearance of NDF after 72 hours incubation coincided with the digestibility of NDF by the total feces collection method. Also the rates of disappearance of individual NDF were definitely different in the order shown below. Italian ryegrass, the leaf, the stem and sheath of sorgo forage The rates of disappearance of dry matter and NDF of the feces were much lower than those of the forages. 5. Comparing NDF with NDF removed lignin, the rate of disappearance of the latter was higher than that of the former by the in vitro method. Especially, in the case of the feces of the stem and sheath, the rate of disappearance of the NDF removed lignin was nearly two times greater than that of the NDF.

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In order to solve the technical problems of a newly-improved beef production system which composed of rearing on pasture and finishing in drylot, for reducing the cost of feeds and saving labor, a series of experiments has been conducted since 1960 to 1972 at Kyushu Agricultural Experiment Station. The study reported herein is the 1st report of this series, and the objective of this study was to know the relation between body weight gain and nutrient intake by fattening young steers on the temperate grass pasture. Two 8-month-old Japanese Brown steers, 209.5, 206.5kg of body weight, were employed in rearing test under rotational grazing at 15 days interval on the experimental pasture with no supplemental feeds from April 1 to September 27 in 1960. The experimental pasture of 37.5 a was divided into fifteen paddocks of 2.5 a having mixture or Orchard grass, Tall fescue and Ladino clover (seeding rate: 0.2, 0.1 and 0.1kg per a, respectively). The experimental results obtained were summarized as follows: 1. Vegetation and its nutrient contents were changed according to conditions, in particular, to growing seasons. During summer, the percentage of grasses in pasture decreased gradually, and that of legume rapidly increased. The crude fiber percentage of grazed herbage on dry matter basis increased gradually from April to June, and subsequently, decreased rapidly with decline in percentage of grasses from July to September. The change of crude protein percentage was in contrast to that of crude fiber throughout the experimental period. These trends were apparently influenced by the changes of botanical composition in pasture. 2. The average daily gain was greatly varied from 0.14kg to 1.65kg between split periods, and less body weight gain was obtained in the latter half of June and the former half of September. The average daily gain in the whole grazing periods was 0.78kg, and the change of body weight gain roughly corresponded to that in digestibility of the organic matter of the forages. 3. Forage intake of young steers on pasture depended on the air temperature, rainfall, and quality and quantity of forage. The green forage intake estimated by chromogen method ranged from 16.3kg to 32.8kg per head a day. The herbage intake on air dry matter basis per head a day averaged 1.8kg per 100kg live-weight in the whole grazing periods. 4. The digestibility of grazed forage was decreased owing to higher air temperature and higher percentage of crude fiber of herbage. The digestibility of organic matter of pasture herbage varied from 81.8 percent in early spring to 42.1 percent in midsummer. 5. Daily gain in each grazing period was in precisely accordance with ADM, DCP and TDN intake. The ratios of ADM, DCP and TDN intake to the Japanese feeding standard for short yearling averaged 71, 136 and 59 percent, respectively, in the whole grazing period. Especially, ADM and TDN intake were insufficient throughout the grazing periods, except in April. 6. Water intake of the steers ranged between 3.5kg and 23.5kg and increased with higher air temperature, less rainfall and lower percentage of the moisture in the herbage. Total consumption of water derived from water bowl and herbages was between 24.1kg and 40.0kg per head a day, corresponding to about 10 percent of the body weight in each grazing period.

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The experiments were carried out in greenhouse from November 1967 to May 1968 to investigate the environmental conditions affecting reproductive growth of red clover plants, using Kenland as early-flowering variety and Altaswede as late-flowering variety. The temperature in greenhouse was 25℃ in the daytime and 15℃ at night and fluorescent lamp (mean light intensity was 360 luxes) was used as supplementary light. The plants were grown under the conditions of short day (12 hrs.), long day (17 hrs.) and combinations of short day, long day and low temperature (2〜7℃). After the investigations in the greenhouse were over, Altaswede plants were sampled and weighed for top and root dry weight. The results are summarized as follows: 1. Growth and flowering of both early- and late-type were accelerated by long day. It was considered that long day was a basic condition for induction and acceleration of flowering. 2. Flowering of both early- and late-type was accelerated by low temperature treatment, when they were grown under their critical day-length. 3. The accumulation of accelerating effect of low temperature on flowering of early- and late-type was largest, when the plants were three months of age after germination. 4. The effect of day-length before and/or after low temperature treatment on flowering of Altaswede was greatest when plants were grown according to the following procedure ; Short day→Low temperature→Long day 5. The effect of day-length at low temperature on flowering was relatively small. 6. Altered day-length (short day→long day) delayed the growth of both types as compared with continous long day. However, in the case of Altaswede when the plants were three moths of age after germination, the ratio of plants with elongating-stems was increased more by this alteration of day-length than by continuous long day treatment.

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1) Experiments were carried out to compare the combined effects of coating methods of pasture seeds with tall fescue (var. Ky 31) and covering of seeds after sowing on the seedling growth and the herbage production. When the seeds were covered with soil after seeding, the number of seedling emergence was two to three times higher compared with surface sowing. Coating treatments were effective under surface sowing and wet coating plot was srperior if the seed was covered with soil after seeding. If the density of the emerged seedlings exceeded 400/m^2, it decreased rapidly by three months. The density seemed to astringe to about 200/m^2 in the summer of the 1st year in case of tall fescue stand. Stubble formation began to appear at the expense of the smaller seedlings. The yields of the control plot and wet coating plot under covered conditions were higher than the other plots in the seeding year but the difference disappeared in the 1st cut of the next year. Swards of the comparatively uniform tiller number of the seedlings and higher production can be expected if the seeds were coated or tabletted before surface sowing. Tabletting seeds is promising if the lowered germination were improved by modifying the direct compression method. 2) The applicability of the coated seeds were investigated on the paddy field soil with Italian ryegrass (var. Mammoth) seeds for spring- and autumn sowing. Germination of coated seeds were lower than that of the control but both yields were high. There was the same tendency for autumn sowing trial. A higher yield was harvested in shallow-tilled plots for uncoated seeds while uncultivated plots gave better results for coated seeds plots in the next spring. The yields of the dry coating plots were high in spite of lower seeding emergence and lager densities.

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In order to find out the most effective method of seedbed preparation suitable for oversowing, an improvement trial was conducted on Miscanthus-dominant grassland with seeds of 5kg/ha white clover and orchardgrass 25kg/ha under 2^4 split plot design involving hoof cultivation, disking, rate of basic fertilizer and pelleting seeds. Lime was applied at the rate of 5t/ha and N, P_2O_5 and K_2O were applied 49, 92 and 46kg/ha respectively for low fertilizer treatment and 3.5 times of these for high fertilizer treatment. The results obtained are as follows ; 1) plant density Plant density of two months after seeding were in the order of HC-D, hc-D, hc-d, HC-d, where HC signifies hoof cultivation, hc control of HC, D disking and d control of D, respectively. Orchardgrass seedlings increased than white clover if the seedbed was well prepared as HC-D and hc-D treatments one month after seeding though they decreased gradually thereafter. Seedling emergence was lower in other treatments and the density did not decrease as the former treatments. Establishment could be judged two months after seeding though the seedlings still decreased thereafter. 2) yield High yields were harvested in the following order ; [table] Vegetation could be improved if the newly developed pasture was properly managed and utilized under high topdressing. 3) effect of disking Disking was most effective as the seedbed preparation and establishment was guaranteed under high fertilizer placement. Vegetation could be even improved successfully with seeding and fertilizer placement in proper season without hoof cultivation nor disking, which shows that the breakdown of vegetation was not always necessary for surface sowing. 4) effect of hoof cultivation Hoof cultivation was effective in breaking the vegetation with grazing and treading wild grasses, but it was not considered to be effective in promoting emergence of sown seeds by treading them into soil. 5) effect of fertilizer High amount of basic fertilizer was not very effective in promoting the emergence of white clover seedlings under disking treatment probably because of fertilzer burn. Orchardgrass seedlings were tolerant to the high rate of fertilizer. Nevertheless higher fertilizer was indispensable for the seedling growth and early production of the sown species. 6) effect of seed coating Though it was not clear whether pelleting seeds of orchardgrass and white clover could be effective in seedling emergence and insuring seedling density thereafter, it was considered promising if the weather condition was unsettled or in a longer spell of dry weeks.

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In the cold region, as in Nemuro-Kushiro district, we have not a lot of days in year to graze cattle on the grassland, because period of frost free is for only 120 days a year. So, it is necessary to prolong the period of grazing which results in a cut down the cost of dairy and beef production. There are two methods to prolong the grazing period: One is to make the beginning of grazing in spring as early as possible and the other is to finish grazing as late as possible in autumn. Although it has been usually recommended to apply fertilizers as early as possible in spring, the deeply frozen soil makes much trouble on the operation of farm tractor and forces to apply fertilizer too late in earlier spring. In this study, we tried application of fertilizer in autumn to hasten the regrowth of grasses in the following spring. The experiment was carried out on humic volcanic ash soil in Nemuro-Kushiro district by using orchardgrass (Dactylis glomerata) and timothy (Phleum pratense) from 1969 to 1970. The results were summarized as follows: 1. Some part of elements of the fertilizers applied in autumn was absorbed by grasses even in late autumn. Absorbed elements were assimilated to the growing leaves when the fertilizing time was the middle of October, whereas the elements absorbed in_ late autumn were stored at the storage organs such as leaf base, stem base, young shoots, corm and roots of plants. 2. The other part of fertilizers applied in autumn remained in the soil without leaching until the following spring, particularly urea remained more than ammoniumsulfate and ammoniumchloride. Potassiumsulfate remained as much as potassiumchloride. 3. Compared with fertilization in spring, autumnal fertilization was favorable for regrowth of grasses in early spring of the following year and caused some increases of the yield of grasses in May, but showed no more difference in the yield in June. This was because the effects of autumnal fertilization extended no longer, while the same amount of fertilizers applied in early spring become more effective in June when the forages were growing rapidly. 4. The effects of fertilization in autumn were a little of difference between orchardgrass and timothy. Namely, by the application of nitrogen in early autumn, orchardgrass was accelerated more in growth and its leaf color got more green in autumn and also in spring. On the other hand, timothy was not so much accelerated by the application of three elements (N, P and K) in autumn, but it reserved these elements more at storage organs before wintering and its growth was accelerated in spring largely. The reason for mentioned above would be explained by some difference in the growing habit in autumn. 5. The contents of total available carbohydrate (TAC) in storage organs of grasses at late autumn decreased by the autumnal fertilization, particularly in orchardgrass fertilized at early autumn. This tendency was accelerated by nitrogen application, but not by potassim. Accordingly, it is necessary to take care of grasses from winter-killing by the reasonable fertilization in autumn.

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A study was conducted to determine the suitable cutting stage of orchardgrass sward from the standpoint of dry matter production. The regrowth of the 1st and 3rd harvest year sward were investigated weekly or fortnighly in each season, under conditions with high precipitation and with top dressings of fertilizer (0.6kg/a each of 3 elements at early spring, and 0.6kg/a each of nitrogen and potassium per cuttjng). The changes of dry matter yield, dry weight of top and whole plant, plant height, logarithmic value of incident light, LAI, number of tillers, dry weight and TAC of stubble in each season were represented well by each cubic regression curve. In spring and summer, the curves of dry matter yield showed similar shapes, and the curves of dry weight of top and whole plant were almost proportional to the curves of yield. Therefore, the curves of dry matter yield might be used as representative indices to determine the suitable cutting stage in spring and summer. In order to obtain the highest yield during these seasons, the average productivity (dry matter yield/regrowth duration) through the seasons must be the highest, and the swards should be cut at the peak of average productivity in each regrowth. The maximum stage of average productivity (C'_<opt>) was calculated by the differentiation of an equation of average productivity (y/x=±b+cx-dx^2) which was obtained from each third order equation of dry matter yield (y=±bx+cx^2-dx^3). The maximum stage of yield growth rate (L'_<opt>) was also calculated by repeated differentiation of the third order equation of dry matter yield. The stages of C'_<opt> and L'_<opt> were calculated by the above methods as c/2d, c/3d, respectively, where c and d represent the regression cofficients. By substituting these c/2d and c/3d into each third order equation, the plant height, LAI, incident light were calculated to be about 74cm, 7.4, 1% at the suitable cutting stage (the maximum stage of average productivity), and to be about 50cm, 4.5, 5% at the the maximum stage of yield growth rate, respectively, except for the very high density sward in the spring regrowth of the 1st harvest year. From the results described above, it may be concluded that the suitable cutting stage in spring and summer can be estimated at the maximum stage of yield growth rate by means of the measurement of plant height, LAI and incident light.

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Growth analysis of orchardgrass swards were conducted using cubic regression equations of dry matter increase for whole plants and LAI which were obtained in the previous paper. Equations of CGR were obtained by the diffrerentiation of the regression equations of dry matter increase. By substituting a value of regrowth duration into the equations of CGR and LAI, the relation between NAR (CGR/LAI) and LAI was obtained as a point. And the curves of NAR to LAI were obtained by the replication of the above procedure changing the substituting values of regrowth duration, successively. The curves of CGR to LAI were also obtained by the same practices. In the early stages of regrowth, the dry weight of the whole plants were decreasing and the values of CGR were negative. Therefore the curves of NAR to LAI showed negative values at the start, and increased rapidly to attain a peak and thereafter decreased gradually under the influence of the progressive intensification of mutual shading of Ieaves, and decreased rapidly around the maximum LAI. These curves of NAR to LAI were quite different from the regression lines obtained by traditional practices. The curves of CGR to LAI and optimum LAI obtained by the above procedure were also different from those obtained by traditional ptactices. The curves of NAR and CGR obtained by the procedure using cubic regression equations were in good agreement with the measured values, and the lines of NAR and curves of CGR obtained by traditional practices did not agree very well with the measured values. The results described above indicate that for the growth analysis in regrowth of grass swards, traditional practices are not appropriate, and more reliable results can be obtained by the proposed procedure using cubic regreession equations of dry matter increase and LAI.

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In order to analyse the growth of autumn seeded dallisgrass and bahiagrass, dry matter production and its distribution among plant parts in relation to plant age and temperature were investigated during autumn and early winter. The results are summarized as follows. 1. The later the seeding time, the more suppresed the increase of the plant age because of the lowering of the temperature. 2. Up to the third leaf stage, little difference in dry weight increase occured due to the seeding time, but a difference occured after the sixth leaf stage. The rate of dry weight gain was higher for early seeded plants, but it decreased rapidly for the late seeded plants. This tendency was seen more clearly in dallisgrass than in bahiagrass. 3. Following the fall in the temperature, the plants become unsuitable for dry matter production because the dry matter distribution to the leaf blades decreased while that of root increased. The dry matter distribution to the various organs in plants was sensitively affected by temperature from the sixth leaf stage, and plant became productive under high temperature, and conversely, unproductive under low temperature. 4. From the above, in order to acquire the potentiality of wintering, it seems desirable that the plant should be grown under higher temperature for some period enough to take a storage type with the lowering of the temperature after about the sixth leaf stage, when the rate of dry weight gain increases sensitively under high temperature.

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In order to analyse the growth of autumn seeded dallisgrass and bahiagrass, the photosynthesis, shoot respiration and some other plant factors relating to those physiological activities were investigated during autumn and early winter. The results are summarized as follows. 1. The later the seeding time, the lower were the photosynthetic capacity and respiratory activity per plant. This result mainly came from the reduction of leaf area enlargement of a plant owing to the lower temperature and hence to the reduction of plant dry weight. Reduction of leaf area per plant was caused mainly by the reduction of dry matter distribution to leaves, of green leaf numbers and of area per leaf. 2. In dallisgrass, photosynthetic capacity per unit leaf area decreased with aging of plant and with lowering of the temperature following the delay of seeding time, and it was little affected by the first frost time. In bahiagrass, on the contrary, photosynthetic capacity per unit leaf area remained fairly constantly high until the first frost time, being affected severely by it. These facts seem to show that dallisgrass can acclimate itself to temperature fall more easily than bahiagrass. In both grasses, respiratory activity per unit dry weight decreased with aging of plant and was little affected by temperature fall following the delay of seeding time, with the exception in the period of the sixth leaf stage when respiratory activity decreased with lowering of the temperature. 3. Some plant factors including the factors mentioned above, vary according to seeding time and the variations become remarkable after the period of about the sixth leaf stage. This tendency seems to be underlied by the susceptibility of respiratory activity (in this paper) and dry matter distribution (in the previous paper) at this stage to the influence of temperature. From the discussion on this situation, it may be gathered that in autumn seeded dallisgrass and bahiagrass, environmental conditions at about the sixth leaf stage critically affect the growth after this stage and the potentiality of wintering.

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The effects of seedling rate, fertilization, cutting time and frequency upon the yields of dry matter and nutrients were studied. It was not hard to obtain 2 to 3t dry matter per 10 are (more than 10t fresh matter) and 1.2t TDN, 0.14t DCP when the initial harvest was cut at heading stage followed by once or twice utilization, provided the field was fertile with much fertilization and the planting density was rather high. More frequent cuttings (4 times during the season) whenever the plants reached around 1m high decreased the yields (1t dry matter, 0.8t TDN and 0.1t DCP). However, sudangrass. may be still profitable in termes of yield as compared with other temperate grasses. It is suggested that sudangrass is a valuable crop to be grown in the southern Tohoku District during the summer time when the temperate grasses suffer from "summer depression".

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In order to investigate the effects of addition of molasses and exhaustion of air on the chemical quality and volatile constituents of fresh rice starw silage, four kinds of experiments concerning 1) control 2) air exhaustion 3) addion of molasses (2% of fresh rice straw) 4) addition of molasses (2% of fresh rice straw) and exhaustion of air at ensiling respectively were planned. The fresh rjce straws harvested with a threshed machine were ensiled in a polyethylene bag silo (0.025cm thick, 40cm diam., 150cm height) at room temperature for 62 days. The methods of packing and chemical analysis were essentially the same as those described earlier. The volatile components were determined using a mass spectrometer equipped with gas chromatograph. 1. Decrease of pH value and increase of lactic acid content were observed in the fresh rice straw silage treated with air exhaustion. Moreover, the addition of some molasses showed a tendency to improve the chemical quality of silage. 2. The contents of higher VFA, above all the valeric and capryric acid contents in the control silage prepared without treatment were very high. 3. Twenty-four or thirty-four peaks were noticed remarkably on the gas chromatograms of volatile constituents of fresh rice straw silage. In these peaks, the following components existed: Acetic acid, n-butyric acid, ethyl alcohol, n-butyl alcohol, sec-butyl alcohol, isoamyl alcohol, linalool, ethyl acetate, n-butyl acetate, isoamyl acetate, phenyl ethyl acetate, ethyl n-butyrate, n-butyl n-butyrate, ethyl palmitate, tridecane, heptadecane, n-octadecane, n-nonadecane, eicosane, 6, 10, 14-trimethylpentadecane-2-one, and phenol. Differences in the peak area distribution among treated silage were observed.

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For the assessment of the gross metabolism in a plant population and community, this paper develops a mathematical method of an interpretation to the theoretical model of the weighted growth of each chemical composition, organ, individual, population and community of the plant, and demonstrates precision and generality of that method according to application of fitting the parameters to this model on a pure population of Sasa paniculata (Sasa type grassland) in Kamishihoro Naitai Grassland, Hokkaido, Japan. The results obtained in this study are summarized as follows ; 1. The general equation of the weighted growth of a plant population and community is defined as the equation (16). When the area studied converges to a point which can be modified by man, the environmental factors contribute to a certain function which can be solved, and the general equation (16) are limited by the simple growth equation (2). 2. The productivity of a plant population and community at any instant in time is calculated by the equation (17). Therefore, the production throughout the period t_1 to t_2 is given by the equation (18). Similarly weekly, monthly and annual productions are defined as the equations (19'), (19'') and (19''') respectively. 3. The maximum growth rate or productivity occurs at the time given by the equation (21) and is given by the equation (22). The yield at that time is obtained by the equation (23). 4. The harvest time for the maximum yield of some chemical compositions and organs of the plant required for man and livestock is selected by the equations (26), (27) and (30). 5. The assimilation, dissimilation and translocation of the carbon and the other elements are estimated as the equations (32) to (38) and application of the equation (17) to the growth analysis on a plant individual, population and community are expressed as the equations (39) to (42). 6. Seasonal data of the dry matter, crude protein, crude fat, crude fiber, NFE, crude ash, C, N, P, K, Ca, and Mg in leaves, stems and above-ground parts of the Sasa type grassland in Kamishihoro lead to the commonly observed sigmoid curve. The weighted logistic equation is fitted by a modification of the iterative procedure of Recklefs (1969) and the least square method to the data obtained (Table 2). 7. The growth spots (for the maximum growth rate) of leaves, stems, above-ground parts and each chemical composition differ from one another. The growth spot of leaves is longer than that of stems (Table 3). 8. The net annual productions of leaves, stems, and above-ground parts of dry matter were 490, 692 and 1, 182g per m^2 respectively, while those of CP were 50.52, 17.30 and 67.82g per m^2. 9. There was no significant relationship between leaf-area index and growth rate in the Sasa type grassland but the correlation coefficient between leaf-area indexes and DM yields was 0.93 and highly significant at the 1% level. 10. At the Naitai Grassland in Kamishihoro, harvesting Sasa paniculata at 104〜107 days from the initial growth stage was selected as the criterion which provided the highest DM yield of leaves in conjunction with high and cosistent levels of CP, the other organic compositions, major and minor elements from harvest to harvest as well as providing persistence of the species.

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