These experiments were made to clear seasonal growth pattern and growth analysis of Ladino clover (Trifolium repens L., race giganteum). 1. Maximum root emergence and axillary bud initiation were observed at a time when herbage growth was generally slow or ceased, viz. from autumn to winter, while maximum herbage growth occurred when root initiation was very slow and decay of old roots took place. It suggests that depression of root may have been due to development of flower primordia, exhaustion by herbage growth and ill effect of high temperature. 2. It was confirmed that the wight of underground organs decreased from April (sprouting period) to August and increased from October to January in a Ladino clover sward. This reduction of underground organs in spring was associated with flowering and maximum herbage growth, especially it being rapid during rainy season. 3. On the relationship between the growth of roots and that of stolons in maximum growing season of underground organs, first stolons became enlarged as a result of high accumulation of reserve foods, part of the foods being consumed for initation and development of roots. Peak of root growth successively occurred after that of stolons in February. 4. Total dry matter production of autumn was almost equal to that of spring, but herbage yields were greatly lower in autumn that in spring. A great deal of assimilation products was translocated to stolon part in autumn, while stored substance in underground organs as well as assimilation products were consumed for herbage growth in spring. 5. Dry matter production was analysed by net assimilation rate (NAR for short) and leaf area index (LAI, F being mean LAI). The relationship between NAR and F was found to be NAR=a-bF, while optimum LAI=a/2b, b value depending vertical distribution of leaf layer and leaf shape. The maximium LAI reached to 5.7 in spring and near maximium LAI was again attained about 4 weeks after cutting. The regression line of NAR calculated was 41.4-7.2F for growing season and optimum LAI obtained was 2.9 in a Ladino clover sward. In order to obtain high yields, it is suggested that Ladino clover stands have to maintain plant height taller than 30cm for regrowth periods.

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Field plot experiments were conducted during 1962-1964 at Kawatabi farm, the soil of which had been covered with volcanic ash, to compare total dry matter yield, production of protein, distribution of their production over each year and change of botanical composition as well as that of density among the following three kinds of sward, i. e. orchardgrass, orchardgrass-perennial ryegrass and orchardgrass-perennial ryegrass-red clover-Ladino clover sward with each 3 levels of nitrogen fertilization. The results obtained are summarized as follows: 1. In the three swards tested, the production of dry matter and protein increased with the increased nitrogen application. The mixture of grass-legume was of higher yield in dry matter and protein than grass sward when applied with low level of nitrogen, but almost similar yields in their production were obtained by heavy nitrogen application. Therefore, it might be suggested that the grass swards could effectively be used to produce enough forage of almost same quantity and quality as the grass-legume swards provided much nitrogen be applied. 2. In grass swards heavily dressed with nitrogen, density of plants decreased through summer and at the last cutting, yield became less by invasion of much weeds compared to that of sward applied with low rate of nitrogen. However, in the next spring, the 1st and 2nd cuts recovered yield much due to heavy tillering and these two cuts produced 2/3 to 3/4 of the total yearly production. The less fertilized grass swards contained less weeds, sustained high density and were more uniformly productive through the season. In grass-legume sward, the similar tendency in responses to nitrogen fertilization was found as in the grass swards, but the former sward was more uniformly productive with less weeds than the latter regardless of the nitrogen amount applied. 3. The nitrogen seemed to depress the clover growth when heavily dressed, and the density of perennial ryegrass and clovers decreased more due to the hot dry weather in the summer of 1964 than that of orchardgrass.

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The conditions of grassland must be examined from two viewpoints, biological and economical. The former is the standpoint of pure science and the latter is that of applied science. The judgement of grassland condition required for the production of meat and milk is zootechnical and economical, but the basis of such a judgement must be biological or ecological. Here the author will propose several criteria of judging the grassland trend and condition ecologically basing on his years' field survey of Japanese semi-natural grasslamds for grazing and mowing use. The ecological judgement of semi-natural grasslands in the forest-climax area like Japan will be equal to the judgement of the progression of plant succession. As one of succession-judgements, the judging method of grassland condition by the biological spectra is firstly proposed. The biological spectra are expressed by the combination of the RAUNKIAER'S dormancy forms, the NUMATA'S migrule forms (disseminule forms D_<1-5> and radicoid forms R_<1-5>) and the NUMATA'S growth forms modifying the GIMINGHAM'S system. The growth forms consist of t, b, e, r, pr, p, 1 and pseudorosette form (ps) as an intermediate type between r and e. Besides these, the spiny or thorny form (sp) will be noticed. The biological spectra are examined according to the species percentage (Sp %) and the dominance percentage (SDR %). We can compare and discuss the biological spectra of short-grass or Zoysia type (Table 3, 4, 5), high-grass or Miscanthus type (Table 7, 8), Sasa-type (Table 9), bracken type (Table 10, 11) and annual type grasslands (Table 12). On the basis of such data, a diagnostic criteria of the grassland condition by the biological spectra is proposed (Table 13). A grassland type covers some wide range of conditions as a seral stage. The figures in the Table 13 indicate the typical or standard state of each grassland by most characteristic items. These judgement are done according to the species percentage and in practical use the difference between the species percentage and the dominance percentage must be discussed. The grassland trend will be estimated by comparing grassland types as seral stages.

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One of the cheepest ways of pasture establishment may be sheep grazing method. Sheep is effective in two respects for establishing pasture: the hoofs press seeds into the ground and subsequent grazing protects seedlings from weeds. In the former experiment of 1961, an improved pasture was established by this method. But because of extremely heavy grazing, the body weight of sheep decreased remarkably. The present study was attempted to achieve both the establishment of an improved pasture and the increase of body weight of sheep by moderate grazing. But an improved pasture failed to be established due to the following reasons: (i) a mass of dead grasses (like mulch) had not been eliminated before sowing and so forage seedlings could not develop their root well into the ground. (ii) after sprouting, forages were covered by native grasses because of light grazing. But in the course of the present study some problems of pasture establishment., i.e., the behavior of sheep, grazing stress and grass species eaten by sheep were clarified.

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Using rabbits as testing animals, the study was done in orchard grass and red clover with the view of finding out the influences of different soil moisture upon the yield of digestible nutrient constituents, such as growth, feeding value and ratio of digestion. 1) In growth of plants, the best condition of soil moisture was at 70-90% of the maximum water capacity in orchard grass and at 50-70% in red clover. 2) In the decrease of absorbing plant nutrients owing to soil moisture shortage, phosphoric acid indicated the largest decrease in orchard grass and nitrogen was next but potassium was comparatively small. In red clover, any obvious effect could not be observed in each constituent. On the other hand, in case of excessve soil moisture, nitrogen was rather remarkable in orchard grass and phosphoric acid in red clover. 3) The difference in percentages of feeding constituents in dry matters was comparatively little. But owing to the fact that the percentage of water in green matters became higher as soil moisture increased, the percentage of each nutrient in green matters of the above-mentioned two plants was the highest in the low soil moisture plots, then in the medium soil moisture plots and the lowest in the high soil moisture plots. 4) The difference between digestibilities by feeding rabbits with two plants was little in protein. In other constituents, the values in the medium soil moisture plots were a little lower than in the low soil moisture plots But the difference between the low and the high soil moisture plots was not remarkable. 5) Every digestible nutrient, TDN and nutritive ratio in the above-mentioned two plants were the highest in the low soil moisture plots, then came the high soil moisture plots and the lowest in the medium soil moisture plots. 6) The yields fo each digestible nutrient and TDN in both of the two plants showed the least in the low moisture plots and increased as soil moisture became higher. This tendency, however, showed some difference among the constituents.

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The subterranean organ of Miscanthus sinensis was analyzed on the basis of four analytic habits: root morphology, root depth root area and vegetative propagation. Characteristics of the subterranean organ of Miscanthus sinensis are summarized as follows: Rm5, RdI, Rs2 and Rv9. The extention of the rhizomes occurs radially from the center of the clone and a dead center is formed in old stub. The expansion and branching of rhizomes are prevented by adjacent rhizomes. In the accumulate sand dune soil, the terestrial organs produced numerous adventious buds and roots and expand obliquely upward. In the grazed habitat, the rhizomes of Miscanthus sinensis occupy a shallow layer, are more or less thin and branching buds decrease. In the ungrazed habitat, the roots occur between 0 and 120cm depth and the working range is 0-50cm. In the grazing habitat the roots occur between 0 and 60cm and working range is 0-10cm, especially, the upper layer being occupied with thinner roots than those in lower layer. But it may be true that there are some shallow rooted plants which can invert the above and well suppress Miscanthus.

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Each one rooted cutting of seventy Ladino clover individuals derived from seven sources was transplanted in an insect-free cage, 2.5×5.5×2.0m, on May 20, 1964. Plants were irrigated frequently after transplanting to develop well-established plants for maximum self-fertilized seed yield and all the heads were picked immediately after fading of flower-stalks. The results obtained are as follows: 1) Twenty eight individuals produced self-fertilized seeds. Less than one seed per head were produced on 26 individuals except 2 individuals which produced 8.9 and 4.4 seeds per head respectively. 2) The rates of emergence of individuals which produced self-fertilized seeds did not vary with sources. 3) It was ascertained that the first flowering dates had no relation to the rates of self-fertility and the number of head had also no influence upon the number of fertilized seed. 4) Both numbers of head and flower which produced self-fertilized seeds were correlated with number of fertilized seed (r=+0.673 and + 0.923) respectively.

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