1. In order to save labor in annual forage crop cultivation and to establish high producing grassland which will make year-round utilization possible by introducing annual forage crop, field tests were conducted to introduce Italian ryegrass by sod-sowing method to pastures of Rhodes grass, orchardgrass, Ladino clover and alfalfa on volcanic ash soil of the Central Experiment Station from 1963 through 1965. 2. Total dry matter yield of thus sod-sown Italian ryegrass was 90-120kg/a and the amount had not much difference to that of customary method (by plowing under former crop and single sowing of the ryegrass), whenever regrowth of the former existing crop had been poor. But when the regrowth had been rich, dry matter yield of the ryegrass was 70-90kg/a, showing 20-30% decrease to that of the customary method. 3. Sum total of yearly dry matter yields of existing Rhodes grass and introduced Italian ryegrass sod-sown was 140-190kg/a, and the amount was much higher than that of the existing perennial crop only. 4. Sod-sowing of Italian ryegrass took less labor than the customary method and this fact together with the higher yield than that of the perennial crop only made the sod-sowing method more promising. 5. It is necessary, however, in making successive cultivation possible by sod-sowing of Italian ryegrass to Rhodes grass pasture to examine following points : i) to improve germination and secure stable grass stand of Italian ryegrass sod-sown to Rhodes grass pasture, ii) to control competition between existing Rhodes grass and sod-sown Italian ryegrass in early growth stage of the latter and iii) to establish the best method of fertilizer application in sod-sowing.

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1. The authors reported in previous paper that introducing method of Italian ryegrass to Rhodes pasture by sod-sowing was promising because of its high yield than that of customary method and its labor saving merit. With similar objectives and technic, field tests were conducted to introduce Rhodes grass by sod-sowing to Italian ryegrass field on volcanic ash soil from 1964 to 1965. In the tests, various sowing periods and sowing systems of Rhodes grass on one hand, and various cutting heights of and amounts of top dressing to Italian ryegrass on the other were taken. Customary plots of plowing under existing Italian ryegrass and sod-sowing of introducing Rhodes grass were taken for comparison. 2. Total dry matter yield of Italian ryegrass was 10-60kg/a higher in non-plowed plot than plowed plot. 3. Total dry matter yield of Rhodes grass was higher in customary plot than any of sod-sown plots, and higher in May sod-sown plot than April and June sod-sown plots. In the plot where regrowth of Italian ryegrass was suppressed by lower fertilization at the time of Rhodes grass sowing, the latter showed better early growth and gave higher yield. In plots where Rhodes grass was broad cast and where it was sown in row, there was no yield difference between them. 4. Sum total of yearly dry matter yields of existing Italian ryegrass and introduced Rhodes grass was 240-260kg/a in May sod-sown plot, and 220-240kg/a in April and June sown Plots. In any of sowing periods, there was not much difference of yield between sod-sown plot and customary plot. 5. It was shown that sod-sown plot gave less forage supply interruption than customary plot throughout a year.

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Lime was applied before rice planting and seed of Italian ryegrass was sown on non-plowed soil in paddy field after rice harvesting. This experiment was carried out in 1963-'64 and the results obtaind were as follows : 1. Liming before rice planting did not increase soil pH as high as we expected, but brought 0.5-1.0 higher pH values than that of unliming in winter crop season. It was effective to produce remarkable high yields of Italian ryegrass. The increase of Italian ryegrass must be due to the secondary factors that liming make the soil nutritious substance more available by raising pH level. 2. Liming before rice planting did not result in lower yields but tended to produce some higher yields of rice. 3. Better germination, stands and higher plant height were obtained in sowing germinant seed than in sowing non-germinant seed of Italian ryegrass. The differences of plant height in both treatments was kept up till after passing the winter. Sowing germinant seed produced higher yields than sowing non-germinant seed, because the former had more main stems than the latter, in addition to above-mentioned matters. Interaction was recognized between sowing of germinant seed and nitrogenous level. 4. By natural soil packing, rate of gaseous phase in plowed soil became almost equal to that of non-plowed soil after passing the winter. It seemed, therefore, non-plowed soil did not give particular harm for growth of Italian ryegrass.

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The authors observed typical summer killing of northern type pasture plants which were sown in late spring and the processes of their withering to death. The killing was not recognized in plants grown under tree shadows nor in areas where plant growth was good, but it heavily took place in areas with poor vegetation exposed to direct sun light. This fact meant that the conditions that lessened tree cover to the ground brought about higher ground temperature and higher soil aridity, those factors in turn giving poorer growth of pasture plants, more frequent summer kiling and extension of naked area of the pasture. Moreover, the results of morphological observation showed that high temperature by direct sun light accelerated senility of plant somatic cells, quickened lignification, developed vessels, increased motor cell numbers, suppressed tissue thickening and thus resulted in bringing xeromorphic form of the plants. These were further confirmed by succeeding complementary experiment. It was recognized that these morphological changes in plant body induced by high temperature caused various hampering factors which gave damages to plant growth and grassland productivity, and promoted summer killing.

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A survey was made on the relationships between planting methods of Italian ryegrass and infection of spot diseases affecting the grass. 1. Infection rate was higher in broadcast plots than in point sowing plots and the rate was lower in cutting treatment plots than in non-cutting ones in spite of the sowing differences mentioned above. 2. Comparing the spot sown-none cutting combination which was selection terms of the grass and the broadcast-cutting combination which was farmer's cultivation terms in general, all of percentage of infected stems, percentage of infected leaves and degree of infection showed similar trend, had not much differences among them and gave highly significant correlation. From this fact, it seems to be preferable to make estimation of the infection in terms of loose individual planting. 3. The infective evaluation can be made by any of infected stem %, infected leaf % and infection degree, but the last one might be more effective. 4. In none cutting treatment plots, in both of broadcast and spot sown plots, infection rate was higher in the lowest leaves. In cutting treatment plots, on the contrary, it was higher in one or two leaves above the lowest one. 5. To make infective estimation by infection degree under the terms of selection then adapted, it was necessary to make it by observing whole leaves in stead of observing few leaves only.

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Qualiative and quantitative determinations were made of the reserve carbohydrates and the component sugars of hemicellulosic substances in the vegetative parts of various species of grasses and legumes. Plant materials employed in this study were leaf-sheathes and stems in heading stage of twenty-five species of grasses and were leaves and stems in the flowering stage of five species of legumes. As reserve carbohydrates in the aerial parts, most species of the grasses accumulated either fructosan or starch usually together with sucrose, and may be able to be classified into three groups by difference in the type and relative proportion of individual carbohydrates as follows. Group 1. Accumulating fructosan, together with sucrose but no starch Group 2. Accumulating starch with sucrose but no fructosan Group 3. Accumulating sucrose but no fructosan The fructosan-containing grasses in Group 1, the sixteen species of the Gramineae, were essentially species of "Northern type" native to cool, temperate climates, and the other eight grasses in Group 2 and 3, which accumulated either sucrose and starch or sucrose only, were species of "Southern type", being adapted to warm regions. According to the HUBBERD system of plant classification, grasses in Group 1 and Group 3 taxonomically belong to subfam. Festucoidea and subfam. Panicoidea respectively, and members in Group 2 belong to three subfamilies of Eragrostoidea, Panicoidea and Banbsoidea. Therefore, there were the two types of reserve carbohydrate in members of subfam. Panicoidea. of seventeen grasses classified to subfam. Festucoidea, red top, bent grass and timothy, members of the Agrostideae, accumulated highest fructosan in relative proportion of individual reserve carbohydrates, and four grasses in the Bromeae and in the Hordeeae contained more plentiful sucrose than members in other tribes of the same subfamily, Festucoidea, although all of them contained fructosan together with sucrose as reserve carbohydrates. The leaf-sheath and stem of most grasses were the same as underground parts with respect to the type of reserve carbohydrate compositions, but were not always similar to the leaf-blades or seeds, which contained higher amounts of starch and no fructosan in most species of the Gramineae. Hemicelluloses of some grasses and legumes were constituted in descending order of aboundance by xylose, glucose or arabinose and galactose, and rhamnose in trace. In comparisons among species of grasses, differences were noted in glucose and in corresponding xylose contents. In hemicelluloses of Southern grasses, glucose was present more plentifully while xylose correspondingly was less as compared with those of Northern grasses or subfam. Festucoidea. When the type and individual proportions of carbohydrate constituents in the aerial parts are considered in relation of taxonomic classification of the Gramineae, it is seen that qualitative and quantitative differences exist respectively with respect to the reserve carbohydrates and with respect to the component sugars of hemicellulosic substances among subfamilies of the Gramineae ; that members of some tribes were quantitatively distinct from members of other tribes in the same subfamily, Festucoidea, in amounts of reserve carbohydrates, such as fructosan and sucrose. Five members of legumes examined contained principally starch with sucrose in aerial parts as reserve carbohydrates and appeared to be distinct from members of the Gramineae in containing more galactose and rhamnose as the component sugars of hemicellulose.

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A study was made of the influence of 2 levels of nitrogen fertilization and stage of maturity on chemical composition and feeding value of soiling rape (Brassica napus L.). Soiling rape was harvested at the vegetative in winter, vegetative in spring, heading, blooming and seed forming stages as shown in Table 2. Each of these stages was treated with low (6kg/10a) and high (18kg/10a) nitrogen levels applied as ammonium sulphate. Digestion trials of soiling rape were carried out with male rabbits of about 2, 500 grams of body weight and its forage was fed in fresh form cut in small spieces to them. The effects obtained due to the high level of nitrogen fertilization were summarized as follows : 1. The contents of crude protein and nitrate increased throughout all the growing stages. 2. The digestibility of crude fiber increased significantly at each stage (except P<.05 at vegetative in winter, P<.01 at other stages of growth). 3. The content of DCP increased significantly (P<.01) and the content of TDN also increased significantly (P<.01) at each stage of growth except vegetative stage in winter. Both nutrients did not show a tendency of conspicuous decrease with the progress of growth. 4. In this study a significant correlation between the crude protein content and DCP content and between the crude lignin content and TDN content was found, their correlation coefficients having been 0.992 (P<.001) and 0.801 (P<.01) respectively. From above results, the crude protein (CP) was the prominent constituent for the prediction of DCP content and the crude lignin (CL) for TDN content, and their relationships are expressed by the following equations : DCP=0.910 CP-1.4 and TDN=82.5-3.471 CL where DCP, TDN, crude protein and crude lignin are shown in percentage of dry matter.

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In the present study, the influence of 2 levels of nitrogen fertilization (high level…24kg N per 10a vs. low level…8kg N per 10a) on chemical composition, digestible nutrients as well as nutritive yields of rye hay (Secale cereale L.) was determined in connection with stages of maturity (boot-leaf emergence, boot and bloom stage) and growth phase (first vs. regrowth). In digestion trials for the evaluation of feeding value of rye hay, rabbits were employed and its hay in meal form was fed to them. 1. Due to the high level of nitrogen fertilization, crude protein content increased at boot-leaf emergence and boot stages in the first growth as well as in the regrowth while NFE content decreased throughout all the growing stages. 2. The digestibility of dry matter, crude protein, crude fat, NFE and crude fiber increased at boot-leaf emergence stage due to the high level of nitrogen but the increase observed in the digestibility of feed constituents was not significant. 3. Due to the high level of nitrogen, DCP content significantly (P<.05) increased from boot-leaf emergence to boot stage and TDN content significantly (p<.05) at boot-leaf emergence stage. 4. DCP yield increased due to the high level of nitrogen fertilization throughout all the growing stages in the first growth while a significant (P<.05) increase was found only at boot stage. In both levels of nitrogen fertilization, DCP yield was highest at boot stage and TDN yield was highest at bloom stage in the first growth. 5. In rye hay by regrowth, the high level of nitrogen fertilization had no effect on the digestibility, digestible nutrients as well as nutrient yields. 6. Feeding value of rye hay drastically declined at bloom stage in the first growth independently of the level of nitrogen fertilization. 7. Correlations between crude protein content, and DCP and TDN contents were statistically significant, their correlation coefficients having been 0.958 (P<.001) and 0.808 (P<.01) respectively.

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1. A field trial was conducted in order to find out how far seed yield of orchardgrass would be influenced by such management as plant density, manuring, etc. 2. As for methods of cultivation, it was demonstrated that interaction between methods of plant density was significant both in the first harvest year and in two year's comprehensive result ; namely, in the case of "sown in situ", more seed yield was obtained in low density than in high density and vice versa in the case of transplanting. 3. As for manuring, the positive effect of manuring was detected all through the two year period. It was considered that increased number of fertile tillers by heavy manuring was responsible for the high seed yield. 4. In comparison of methods of planting, higher seed yield was obtained in transplanting than in "sown in situ". Interaction was detected, however, between years ; namely, the second harvest year outyielded the first one in "sown in situ" and vice versa in transplanting. 5. Analysed into several components of seed yield such as number of fertile tillers, number of seeds per panicle and seed weight, it was considered that increased seed weight was most responsible for the higher seed yield of the first harvest year, that manuring stimulated the increase of number of fertile tillers and that increased number of fertile tillers and that of seeds per panicle of the transplanted could surpass those of the 'sown in situ' in seed yield.

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Twenty-one timothy and 25 orchardgrass varieties replicated three times in solid stand were studied for the 3-year period of 1963-65 to secure information on the interrelationships among several characters influencing seed yield, and to evaluate seed-producing ability of domestic and introduced varieties of the two grasses. Domestic varieties produced more seed than those of introduced varieties in timothy. In orchardgrass, however, the seed-producing ability of the most introduced varieties exceeded that of domestic ones. The results from analysis of variance for all characters measured showed that highly significant difference existed among varieties in both years. By a simple correlation-coefficient method, culm length, seed weight of 100 panicles and weight of 100 seeds were found to be positively correlated with seed yield in timothy. Whereas two factors of culm length and panicle number were positively correlated with seed yield in orchardgrass. However, the path-coefficient analysis gave somewhat a different picture. It indicated that seed weight of 100 panicles and weight of 100 seeds had the greatest influence on seed yield, while culm length had only minor effects in timothy. In orchardgrass, panicle number was the only factor affecting both directly and indirectly upon seed yield, and culm length which had a strong correlation with seed yield by a simple correlation-coefficient method seemed to be less important factor.

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