There are few ecologically "natural" grasslands in Japan which belong to the forest climate in terms of the phytoclimate. In a word, the grassland as a true climax in our country is only the alpine grassland above the tree line. The others are either seral stages or the grasslands maintained by human activities such as mowing, grazing, or firing. Semi-natural grasslands as those have been studied by many Japanese ecologists. However, artificial grasslands have not been studied so much ecologically. The authors have intended to analyse the community structure and succession of some artificial grasslands. The sown pastures of different ages in the field of the National Institute of Agricultural Sciences, Chiba were selected to study. The grassland vegetation was measured four times a year by means of the stratified random sampling method with 20 quadrats of 30×30sq. cm or 50×50sq. cm as a basic sampling unit. The nest quadrat method with sides of 7.5, 15, 30, 60, and 120cm was used too. As criteria to diagnose the condition and trend or the health and deterioration of the sown pasture, the floristic composition expressed by the summed dominance ratio: (D'+F'+C')/3(%) and the weight ratio, the number of individuals-rank of species relations in terms of the law of geometrical progression, the dispersive structure (modes and types of distribution), and the biological type spectra were examined. It is concluded that the relative importance of constituent species is to be estimated not only by the standing crop but by the summed dominance ratio; the relative importance including the homogeneity concept is estimated correctly by the coefficient of homogeneity (h) which is useful for the production ecology too; the linear relations from the number of individuals-rank of species standpoint indicate a kind of the stabilization of interspecific competition; and the increace of geophytes, hemicryptophytes, nanophanerophytes, and rhizome plants expresses the deterioration of the sown pasture.

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It is considered that about one-third of the range area is the vegetation of SHIBA grass (Zoisia japonica) in Japan. In our experiments it was found that the Zoisia range had a habit of ever produces the feed suitable for grazing by live-stock. If the Zoisia grass is cutted rather closely more than once during the month, the interval between such cutting must be sufficient for it to recover fully. Therefore the grazing capacity may be increased to 24,000kg a year by giving a small quantity of nitrogen, in spite of the poor appearance of standing crop of Zoisia grass.

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Variations in some morphological characters of Miscanthus sinensis ANDERSSON, M. sinensis var. condensatus MAKINO and M. sinensis form. gracillimus OHWI were studied in 1955. 1. Length of the leaf blade in M. sinensis and wild M. sinensis var. condensatus ranged from 47cm to 98cm and from 48cm to 87cm respectively. Breadth of the leaf blade in M. sinensis, its variety and form are 1.0-2.7cm, 1.1-3.1cm and 0.4-1.5cm respectively. Especially, cultivated varieties of M. sinensis var. condensatus are so wide as 3.1-4.2cm (Figs. 1 and 2). 2. Length of the culm and the ear in M. sinensis is generally larger than that of the varieties (Fig. 3). 3. Bush-type of these grasses may be classified into three types according to an index given by the formula T=D-D'/H (T=index of the bush-type; D=diameter of the maximum spread at the top of the bush; D'=diameter at the base of the bush; H=height), i.e. erect type (T<1), decumbent type (1<T<2) and prostrate type (T>2) as shown in Fig. 5. Most individuals of M. sinensis grasses belong to erect type, and its variety is either prostrate type or decumbent type (Fig. 4), but the grasses grown at sea cliff show extremely prostrate type. This type is regarded as edaphic ecotype by TURESSON (1925). 4. In this report the writers recognized the continuous variation in these morphological characters.

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The proper time treated with conc. sulfuric acid to break hard seed and hasten the germination were investigated, using the seeds of six wild leguminous plants. The results obtained were summarized as follows: 1. The proper time of conc. sulfuric acid treatment varied according to the kind of seeds. On Lespedeza juncea, 40min.: on Lespedeza cyrtobotrya, from 20 to 60min.: on Indigofera pseudo-tinctoria, from 20 to 40min.: on Vicia sativa, from 5 to 10min.: on Cassia mimosoides, 5min. and on Aeschynomene indica, from 5 to 60min. gave good results. 2. In these proper treatment, the germination were hastened and from 80 to 98 percent of the total germination weae obtained at the end of the sixth day and from 87 to 99 percent were at the end of the tenth day.

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1. This experiment was undertaken to determine the suitable methods and kinds of grass converting banks from natural grassland into artificial grass covers. 2. This experimental plots were as follows. A) Seeding in parts where cultivated as stripe along same heigh level. B) Seeding by broadcast method into many circle-ploughed parts. C) Seeding into little scratched hollows. D) Seeding by broadcast method on total area. 3. The results obtained were summerised as follows. i) In the above 4 methods A)-plots were the best, B)-, C)-and D)-plots showed somewhat similar achievements. ii) The difference between the methods was scarcely, but it between kinds of grass was obvious, that is, both the Orchard grass-Ladino clover and the Timothy-Red clover mixture was much better than Orchard grass, Ladino clover, Birds-foot trefoil and White clover alone by yields of green forage, weight ratio of grass per weed and cover degree. iii) The autumn ought to be selected for the optimum sowing time of grass.

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A study of the effect of low and high moisture conditions on the fertilization of Red clover was made in glasshouse and field. In this study, the following methods were designed. moisture: low (40〜50%), high (95〜100%) and field (70〜80%) conditions. date of harvesting: The 10, 15, 20, 25, 30th days after crossings. Above crossings were all done artificially. The crossings in low and high moisture conditions were carried out in glasshouse. (1). Ratio of fertilization Average ratios of fertilization were 50.10% in low, 36.12% in high and 45.00% in field conditions. More seeds were gained in low condition than in high condition. (2). Seed weight (a). Average weights per seed were 2.23mg in low, 2.05mg in high and 1.58mg in field conditions. (b). The seeds reached to almost equal maturity as well matured seeds on the 10th day after the pollination in low, 15th day in high and 30th day in field conditions. (3). Ratio of germination Ratios of germination increased rapidly on the 25th day after the pollination in low, 30th day in high and 25th day in field conditions, and better seeds were gained in low condition than in high condition. (4). Ratio of hard seed Ratio of hard seeds was 40.0% on the 10th day after the pollination in low condition, and less hard seeds were gained in low than in high conditions. The ratio of hard seeds was 30.2% on the 30th day after the pollination in high condition.

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