Fresh and wilted Italian ryegrass samples were ensiled at a heavy (unit quantity of 600kg/m^3, …H) or light (unit quantity of 300kg/m^3, …L) compaction level respectively and resultant silages (two high moisture and two wilted ones) were fed to castrated male goats in order to compare the digestibility and efficiency of nitrogen utilization between silages made at different compaction levels. The chemical quality of silage was exceedingly higher for the (H) in a high moisture silage, but there was little difference in quality between the (H) and (L) in a wilted one. Digestibilities of dry matter, crude protein, NEF and crude fibre in a high moisture silage and those of crude protein, NEF and crude fibre in a wilted one were all significantly higher for the (H) than the (L). DCP and TDN contents were significantly higher for the (H) than the (L) both in high moisture and wilted silages. Significantly more nitrogen was retained for the (H) than the (L) both in high moisture and wilted silages. The differences in the digestibility and efficiency of nitrogen utilization between the (H) and (L) silages are seemed to be mainly due to the difference in chemical quality between these silages.

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In the present paper, the mode of changes of nutritive value and production was examined in orchardgrass, tall fescue, meadow fescue, perenial ryegrass and timothy, harvested at different cutting schedules. Grass samples used in the experiment were supplied in the two cutting schedules: Cutting schedule 1: This is the schedule of early and frequent cutting with shorter intervals. Cutting schedule 2: This is the schedule of late and prolonged cutting with longer intervals. Results obtained were as follows: 1. DCP and TDN content in grasses had increased in accordance with increasing cutting frequencies. TDN content in regrowthed grasses during summer-time was decreased irrespective to kind of grasses and cutting schedules. 2. TDN production was higher in the cutting schedule-2, however, DCP production was higher in the cutting schedule-1. 3. Weighted average (production per dry matter per cent) of DCP and TDN was higher in the cutting schedule-1.

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This experiment was carried out not only to understand the relationships between population densities and individual variations but to estimate the nature of the interractions among individuals in a population indirectly from the type and the time trend of the frequency distribution of the agronomic characters of timothy. Two kinds of population namely, a variety, which is genetically heterogeneous, and a clone, which is genetically homogeneous but more or less variable among plantlets, of timothy were grown at three densities, 5, 10 and 15cm square respectively, under high and low fertilizations and were cut two times in one year over four year experiment. The plant height, the tiller number and the dried plant weight were recorded for individual plants. 1. The frequency distributions of the plant height changed with cutting times. The appearance of the negatively or positively skewed distributions together with the normal ones led to a supposition that the equalization and the competitive interaction of the plant height may be at work in opposing directions. 2. The frequency distributions of the tiller number were positively skewed under all treatments. The developments of the skewness for the variety population were greater than that for the clonal population. In many cases, the positive skewness of the frequency distribution was promoted by increasing plant density under the high fertilization. 3. The frequency distributions of the plant weight were more skewed than those of the tiller number. The responses in the development of the skewness for the plant weight by the treatments were identical with the pattern for the tiller number. 4. The relationship of the plant height and the tiller number to the plant weight was investigated. The tiller number showed a higher association with the plant weight than the plant height. 5. The marked variations of the size of plants at dense populations planted at 10cm or 15cm square could be of value to selection by a clearer distinction between low and high-yielding plants.

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Two experimental parts for influence of temperature on the growth of three cultivor of alfalfa, were conducted and are discussed as part I and part II. One-year-old plants of "Vernal", "Cody", and "Florida 66" were grown in three growth chambers set at different temperature regimes ; (1) hot (H) 32℃ during the day and 27℃ at night ; (2) warm (W) 27/21℃, and ; (3) cool (C) 21/15℃ All chambers had an 18-hour photoperiod of ca. 21, 500lux (ca. 6.3g Cal/cm^2/hr.). In part I, plants were harvested on a time basis. Each variety were harvested, when "Florida 66" reached first flower at 27 days. In the second part, all cultivars were harvested, when each variety reached first flower. In part I, the maturity of three cultivar was delayed as temperature decreased from 32/27℃ to 21/15℃. Shoot height and weight of plant parts for each cultivar were greatest in the (W) regime. The highest weight of all plant part was obtained in (W) regime except for weight of root and crown, followed in descending order by the (H) and (C) regimes. Total plant yield was highest in the (W) regime and was progressively lower in order with the (H) and (C) regimes. TNC concentrations of leaves and stems were increased as temperature decreased. Among cultivars, "Florida 66" had the highest concentration of TNC, in each plant part, while differences between "Cody" and "Vernal" for concentrations of TNC were insignificant. In part II, "Vernal", "Cody", and "Florida 66" reached the first flower stage after 27 to 32 days in the (H) regime, after 32 to 36 days, in the (W) regime, after 42 to 49 days in the (C) regime. "Vernal" flowered significantly later than the "Florida 66" and "Cody" in all three temperature regimes by 3 to 5 days. Average shoot height for each cultivar at the first flower stage was greatest in the (W) regime followed in descending order by plants in the (C) and (H) regimes, but there were no significant differences among cultivars. The highest weight of all plant at the first flower stage for three cultivars was obtained in the (C) regime, except for weight of stem from "Cody." Among cultivars the highest weight were obtained in the "Vernal" except for weight of roots in the (W) regime. Total plant yield was highest in the (C) regime and progressively lower in the (W) and (H) regime, and among cultivars, "Vernal" alfalfa was highest. The TNC concentrations of leaves and crown were highest in the (C) regime, except crown of "Vernal." There were no significant difference in percentage of TNC of stems and roots in the three regimes. Plant growth rate (mg/pot/day) of leaves and roots were increased as temperature decreased. Among cultivars, the rate of "Vernal" was highest, and the difference between "Cody" and "Florida 66" was not clear. The accumulation rate for leaves and stems was highest in the (C) regimes and among cultivars "Vernal" was higher than the others.

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Effects of the various treatments on reducing the temperature and the light requirements for germination of Japanese lawn grass (Zoysia japonica Steud.) were studied in some detail following the previous papers. In the first experiment, diverse germination responses corresponding to the treatments employed and the germination conditions prepared were demonstrated (Fig.1). In the next experiment, interrelations between duration of chilling period and kind of the chemical treatments combined were also clarified concerning the regulation of germination responses (Fig.2). Some important facts verified from these experiments were: 1) the combined chemical treatments, NaOH+(GA_3+KNO_3), for adequately chilled seeds-a prescription which has previously been given by the author tentatively-were the most favorable in their effects on acceleration of germination, 2) the same effects as those described above, on the other hand, were obtainable even by NaOH treatment alone, when the seeds were chilled as long as about 90-day period instead of the 30-day's. Besides these experiments mentioned above, some additional problems concerning the effects. of drying to prevent the loss of vigor in prolonged chilled seeds, and the variations in the effects of the treatments due to the differences of the origin of seed populations were examined. Finally, the ecological significances in application of these treatments were briefly touched upon.

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In order to open up the possibilities of the extention of the grazing season in early spring for the cold and snowy districts of Japan, the effects of promotion of snow melting by broadcasting carbon black powders on to the snow surface on grass yield and on early spring grazing were investigated. Results obtained were as follows: 1. Promotion of snow melting was effective for the grass yield in early spring. The largest causes for the effective grass yield were sharp rise of soil temperature and enabling the grass receive direct sunlight after snow melting. 2. By combining such rise in soil temperature and N-fertilization, it is possible to secure grass growth required for grazing in early spring. 3. Based on the results obtained from the abovementioned studies, a field trial on the extention of grazing season was undertaken in pasture, and it was possible to advance the spring grazing earlier than 10 days as compared with conventional grazing. Such grazing in early spring is not only effective for gain of body weight of stock, but also for evening up spring flush for grazing.

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Subtropical grasses were compared in pot culture experiment in their responses to nitrogen fertilizer as a first step to investigate the effect of nitrogen fertilization on controlling the competition among species in subtropical pasture. The grasses used were Rhodesgrass (Chloris gayana Kunth.), dallisgrass (Paspalum dilatatum poir.) and bahiagrass (Paspalum notatum Flugge.). They were grown in a glasshouse at Faculty of Agriculture, Miyazaki University from 10 July to 29 August 1973. Nitrogen fertilizer was applied at five levels, 0, 0.25, 0.50, 1.00, 2.00g-N/pot, in the form of ammonium nitrate solution on three weeks after seeding and plants were harvested four weeks after nitrogen application. The average daily maximum and minimum temperature in the glasshouse during the experimental period were 35.8 and 20.7℃, respectively. Results were summarized as follows: 1. Rhodesgrass showed the highest dry matter yield with increment of N rate, followed by dallisgrass and bahiagrass. Also, N rate at which dry weight reached the maximum was the highest in Rhodesgrass and the lowest in bahiagrass. Similar trends were shown in their stem numbers. 2. The nitrogen yield of Rhodesgrass was increased almost linearly up to the highest N rate (2.00g-N/pot) and recovery of applied-N in whole plant of Rhodesgrass was ranged from 84.0 to 76.0%. Nitrogen yields of dallisgrass and bahiagrass, however, were not always increased with increasing applications of nitrogen, and their nitrogen recovery was declined from 87.0% at 0.25g-N/pot to 44.6% at 2.00g-N/pot in dallisgrass and from 71.0 to 17.3% in bahiagrass, respectively. 3. The value of dry matter yield per N yield (W/N) was declined with increase of N-applied in all species, however, Rhodesgrass always showed the highest W/N value at the same N-applied level. These results suggest that differences of W/N value in relation to species and Napplied are one of important factors which influence the efficiency of dry matter production and the plant competing ability for nutrient under high nitrogen fertilization in the pasture. Therefore, further study will be needed to clarify the factors influencing W/N value.

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During 1972 and 1973 a field experiment was conducted at Fukuoka, Kyushu, using the mixed stand of Setaria sphacelata cv. Kazungula (Ks) and Desmodium intortum cv. Greenleaf (De) and the individual components grown in pure under two different clipping treatments, i.e., 50 and 70cm clippings, which were conducted when Ks plants in pure reached to the height of 50 and 70cm, respectively. Items studied include growth habits, dry matter and nitrogen yields, and canopy structures together with light interception profiles through canopies. The plants were arranged in 20×20cm grid in pure stands and alternately in the mixed stands. Fertilizer was dressed in the form of compound fertilizer (16% each of the three elements) and the rates of dressing were 8 and 13.5kg/10a in 1972 and 13.5kg/10a in 1973 for each element. Results obtained were as follows, 1) Mixed stands outyielded either De and Ks in pure in dry matter and averaged 1000-1100kg/10a in 1973. Fifty cm clippings increased dry matter production of the mixed stands more than 70cm clippings. This favorable "Legume effect in terms of the increased dry matter production" was calculated by subtracting dry matter yield of Ks in pure from total dry matter yield of the mixed stand and estimated in 1973 to be 86-130kg/10a. 2) As for nitrogen contents in plant tops throughout seasons Ks in mixture exceeded Ks in pure whereas De showed an opposite trend. Fifty cm clipping exceeded 70cm clipping in nitrogen yield in the mixed stand, showing that somewhat frequent clippings may be effective to increase nitrogen yield. Except for 70cm clipping in 1972, mixed stand exceeded De in pure in the total amount of nitrogen yielded in plant top. It is attributable to "Legume effect in terms of the increased nitrogen yield, " which was estimated by subtracting nitrogen yield of Ks in pure from the total nitrogen yield of the mixed stand. Amounts estimated were equivalent to 6-24kg/10a of nitrogen fertilization provided two-thirds of applicated nitrogen could be recovered in plant top. The transfer rate of nitrogen from De to Ks component were less in early stage of establishment than in other growing periods, suggesting that some nitrogen application right after the seeding of De may be practical to promote total production of the sward. 3) Canopy structures and light interception profiles through canopies in the mixed stands showed a somewhat combined type of individual pure stands and were supposed to have some advantage over them in regard to the efficient utilization of solar energy and the above ground space. 4) Results above obtained in addition to prevailing characteristics of tropical legumes and grasses could suggest that legume species such as De might be promising in southwestern Japan especially when grown with suited tropical grass like Ks.

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A rank, which was based on the number of vascular bundle rings of roots, was given to each root as follows ; "I" was given to the root with one vascular bundle ring at its base. In the same manner as above, ranks II, III, …were given to each root. The root of the highest rank in a root system was designated as the indicator root. Moreover, different kind of rank, which was based on the rank of the indicator roots, was given to each root system as follows ; R-I was given to the root system carrying the indicator root of I. In the same manner as above, ranks R-II, R-III, …were given to each root system. This method was applied to classify and to present root systems in a natural population of Kudzu vines which had passed through about 25 years since its invasion. The range of the ranks obtained from this investigation was R-I to R-VIII. The following characteristics in composition of the root systems were recognized ; The average number of the indicator roots decreased gradually with the rise of the rank of the root system and was 1.00 in the root systems above R-VI. The average number of roots belonging to relatively higher ranks except the indicator root also tended to decrease gradually. In most ranks of root system, the average number of these roots was less than 1.00. On the other hand, the aveoage number of roots belonging to II did not change very much. The average number of roots belonging to I tended to increase. It was suggested that the rank of the root system in our method had some relation to the developmental stage of the root system. This method will enable us to classify quickly and to present root system in a simple way.

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The Notsukezaki sand spit pasture has been considered as a typical pasture vegetation of Subartic climatic zone in Japan. We investigated the seasonal and yearly trend of the vegetation during the years of 1972-1974. The results of investigation are as follows: 1. The flora of the pasture vegetation was consisted of about fifty species. The dominant species of the community were Festuca ruba, Thermopsis lupinoides, Carex verna var. microtricha and Agrostis hiemals, and the other major species were such as Rosa rugoa, Geranium yesoense var. pseudapalustre, Potentilla egedei var. groenlandica, Galium verum var. trachycarpum and Calamagrostis langsdorffii, mast popular constituents of the semi-natural coastal grassland in Hokkaido. In addition, Poa pratensis and Trifolium repens which were widely colonized in the island were also present. 2. The maximum number of species was recorded in July, and the ground was primarily covered by Festuca rubra and Thermpris lupinoides which dominated throughout the whole growing season. In spring, summed dominant ratios (SDR_3) of Polygonatum humile, Fritillaria camtshatcensis and Poa mcrocalyx var. scabiflora were increased. Thermpris lupinoides, Agrostis hiemalis, Ranunculus francheti, Geranium yesoense var. pseudo-palustre and Trientalis europaea var. europaea were prevailing in summer. In fall, Poa pratensis, Stachys japonica var. villosa, Scutellaria strigillosa, Trifolium repens and Elymus mollis were increased in the sward. 3. The dominant species in the grassland were essentially unchanged since 1972. But some species such as Thermopsis lupinoides and Calamagrostis langsdorffii gradually declined with advancing years. On the contrary Carex verna var. microtricha, Trifolium repens and Luzula capitata incleased their density. 4. The vegetation of Notsukezaki sand spit pasture seems to be changed from Thermopsis lupinoides-Calamagrostis langsdorffii community of tall-grass type to Festuca rubra community of short-grass type by trampling of domestic animals and motor cars. 5. Degree of succession of the pasture vegetation in summer was rather stable since 1972 to 1974, but the difference in DS values between grazed plots and protected ones indicates that the degree of succession of Notsukezaki sand spit pasture has been lowered by the grazing of beasts and other artificial pressures.

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