1. To know of the applicabilities of hoof-cultivation method as a grassland development technique on the area where heavy machines or implements cannot be successfully introduced, it was studied on natural grassland comparing with conventional improved pasture for three growing seosons. The whole experimental area was covered with typical natural grasses of tall type, such as zebra grass (Miscanthus Sinensis Andress), Japanese lespedeza (Lespedeza bicolor Turcz), sasa (Sasa Kurilensis Var. Uchidai Makino) and ferm (Pteridium aquilium Kuhn). And also, the second growth of white birch trees were grown 3,400 plants per ha, average height being 3.9 meters. 2) Average stand number of sown grass at the first year on hoof-cultivated pasture, stocked area had 78 grasses and 36 legumes per square meter, but in non-stocked area only the half. Conventional disked pasture had twice as much grass stand that of stocked area. 3) Hoof-cultivated and disked pasture were grazed twice in the first year, five times in the second year and six times in the third year depending on the vegetation conditions at the average 65% of grass utilization rate. As a result, first grazing time of second year on the hoof-cultivated pasture showed good vegetation, there being contented 83.7% of sown grass (54.3% of legumes). There was no large vegetation difference between hoof-cultivated and disked pasture. 4) Natural pasture produced 36.6 tons of utilizable green grass and allowed 693 cow days per ha for three years. Hoof-cultivated pasture did 107.5 tons of utilizable green grass and 1,646 cow days. In the case of disked pasture, it produced 117.4 tons of green grass and did 1,809 cow days. 5) Average of eaten nutritive quantities per cow per day were tested by clipping method for three years. Dry matter of 12.4 Kg, 1.56 Kg of DCP and 8.41 Kg of TDN were eaten on the natural pasture. Hoof-cultivated pasture produced 9.2 Kg of DM, 1.91 Kg of DCP and 6.79 Kg of TDN. Disked pasture did 7.6 Kg of DM, 1.89 Kg of DCP and 6.06 Kg of TDN. 6) It was found that hoof-cultivation method may be used as a new pasture technique for a grassland development on native hilly land. Principles of the method may be summarized as follow: (1) Burning; to make good soil surface, (2) Bacic fertilization; reasonable amount lime and phosphorus, (3) Sowing seed; legumes and grasses, (4) Stocking; 70 cow days per ha may be enough for good stand of the plants introduced and (5) Grazing; control grazing is very important. 7) It was shown that stocking time and rate, timing of first grazing after stocking and fertilization rates might be needed for further experiments.

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Some observations were made on insect and disease which were concerned with root decay of taproots of Ladino- and red-clover. Larvae population of clover weevil (Scepticus gricius) in the soil of Ladino clover sward was at the highest in the middle of May and it decreased towards the end of June. This coincided with the occurrence of surface gnawing on the taproot of Ladino clover as reported in the previous paper. Dusting of insecticide, aldrin 50 Kg per ha, was effective to reduce the population of this larva. Root rot fungus, Rhizoctonia solani KUHN isolated from red clover, was inoculated on red clover seedlings grown in sterilized soil to ascertain in what extent this fungus would be related to root rot. The same root decay was observed on the inoculated plant as well as by field survey, which indicated that this fungus could be one of the causes of root rot. Drenching of organic mercurial in the soil proved to some extent to control this disease of both clovers. When the soil was sterilized by heating, instead of chemicals, all plants survived completely throughout the experiment, none of their taproot decayed and their root weight reached nearly twice as much as that of untreated plant.

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The purpose of this trial was to determine the influence of levels of nitrogen fertilization, stage of maturity and growth phase on chemical composition and feeding value of Italian ryegrass forage (Lollium multiforum Lum.). A high level of nitrogen was applied at a rate of 18 Kg. per 10 a at sowing time and 6 Kg. top-dressing after first cut forage was harvested and a low level of nitrogen was one-third of the high level on each occasion. The first cuttings were made at vegetative, boot, head and milk stages of growth respectively. The aftermath forage was harvested at head stage. The harvested forage was fed in fresh form to rabbit. (1) High level of N fertilization increased protein content in the first cut forage throughout all growing stages and in the aftermath forage received top-dressing N fertlizer, and digestibility of the crude protein also increased significantly (P<0.01 except p<0.05 at milk stage) when compared to low level of N fertilization, but this effect was lost in the aftermath forage untreated. High level of N fertilization had no effect on content of crude fiber and crude lignin at different growth stages. There was, however, a statistically significant (P<0.05) increase in digestibility of crude fiber due to this treatment at vegetative and boot stages. This treatment also significantly (p<0.05) increased digestibility of dry matter at vegetative and milk stages, while this effect on those of crude fiber and dry matter disappeared in aftermath forage. (2) A variation of digestibility of all constituents of high level of N fertilization with advanced stage of maturity was similar to that of low level of N fertilization, but the variation of digestibility of crude protein and crude fiber of high level of N fertilization. Digestibility of all constituents declined markedly at head stage in the first cut forage. Regardless of top-dressing of N fertilizer, digestibility of dry matter, nitrogen-free extract and crude fiber in aftermath forage was lower than that of the similar stage in first cut forage, but those of other constituents were as high as those in the first cut forage. (3) There was a highly significant increase in DCP and TDN content due to high level of N fertilization at all growing stages in first cut forage and in aftermath forage which received top-dressing of N fertilizer. Both contents decreased sharply from boot to head stages and then remained almost unchanged. (4) There was a highly significant increase (P<0.01) in DCP yield per 10 a due to high level of N fertilization at all growth stages in first cut forage and in aftermath forage which received top-dressing of Nfertilizer. This effect on TDN yield was also found significantly (p<0.05) at head stage and milk stage in first cut forage and in aftermath forage untreated. Yields of DCP and TDN per 10 a obtained from both levels of N fertilization were greatest at milk stage. (5) Crude protein content was highly correlated positively (r=0.994) with digestibile crude protein content.

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This trial was carried out to determine the influence of nitrogen fertilization (8 Kg vs. 6 Kg per 10 a) and stage of maturity (boot, tassel, silk and milk) on chemical composition and feeding value in flint corn fodder harvested and fed in fresh form to rabbit. The results obtained were as follows: (1) The contents of crude protein increased by high level of N throughout all growing stages, while the contents of nitrogen-free extract decreased. (2) There was an increase in digestibility of crude protein due to the high level of N at any other stages expect milk stage, but a significant (p<0.05) increase was only at boot stage. A significant (p<0.05) increase in digestibility of crude fiber also was found at boot and tassel stages. (3) The influence of level of N on a variation in digestibility of all constituents with stages of growth was not recognized. The most rapid decline in digestibility of dry matter and crude fat occured while the corn fodder advanced from boot to tassel stages, then they remained constant to silk stage and again rose at milk stage. Those of crude protein, crude fiber and nitrogen-free extract showed the greatest decline to the silk stage and then turned to a slight rise. (4) There was a increase in DCP content due to high level of N at all growth stages, but a significant (p<0.05) increase was found at boot and tassel stages. The influence of high level of N on TDN content did not appeare at any growth stage. (5) The DCP content of high level of N declined sharply from vegetative to head stages and remained almost unchanged from silk to milk stages, while that of low level of N remained almost constant during the growing stage. The TDN content of high level of N declined sharply during the growing stage until silk stage and turend to a rise, but that of low level of N declined gradually from boot to silk stages and then turned to a rise. (6) The DCP yield per 10 a of corn fodder grown under high level of N increased significantly (p<0.05) throughout all the growing stages with compared to that of low level of N and the TDN yield also increased significantly (p<0.01) due to high level of N at tassel, silk stage and milk stages. (7) The crude protein content was highly positively with digestibility of dry matter, crude protein and crude fiber, and the DCP content. In order to predict the DCP content in corn fodder, the content of crude protein (CP) was the satisfactory constituent and could be predicted by the equation DCP=0.792 CP-2.20 (S. E. of estimate: 0.47).

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This study was carried out to determine the influence of a level of nitrogen fertilization in connection with stage of maturity on chemical composition, digestibility and nutrient yield of oats forage. Oats forage cultivated under a high level of nitrogen fertilization (25 Kg per 10 a) and a low level (8 Kg per 10a) was harvested at 4 successive stages of growth, namely: vegetative, boot, head and milk stages and fed in fresh form to whether sheep. The results obtained were summerised as follows: (1) The changes in chemical composition resulting from the high level of N fertilization were a marked increase in crude protein content at vegetative and boot stages, a decrease in NFE content at all growth stages and a slight decrease in crude fiber and crude lignin content at all growth stages with the exception of vegetative stage. (2) While plant was advancing from vegetative to head stage, crude protein content in oats forage with high level of N application sharply decreased when compared to low level, but the other chemical compositions had no effect due to high level. (3) There was an increase in digestibility of crude protein due to high level at all growth stages, but a significant (p<0.05) increase was found at vegetative stage. A slight increase in that of crude fiber due to high level was also found at vegetative stage, but its increase was non-significant when compared to low level. (4) The effect of the level of nitrogen fertilization on a variation in the digestibility of all constituents (except crude fat) with increasing maturation could not be found. These variations decreased gradually until head stage, and thereafter those of dry matter and crude protein remained constant, while those of NFE and crude fiber decreased slightly. (5) There was a highly significant (p<0.01) increase in DCP content due to high level at all growth stages, but non-significant in relation to TDN content. (6) The variations of DCP and TDN content with advancing stage of maturity were similar for the two levels of N fertilization. The DCP content decreased until head stage, especially that in oats forage grown with high level of N decreased sharply, and thereafter almost not changed. The TDN content of the high nitrogen stand straightly decreased as oats forage advanced in maturity from vegetative to head stage. That of low nitrogen stand remained almost constant until boot stage, and then, after reaching the lowest content of TDN at head stage, remained again constant. (7) There was a significant (p<0.05) increase in DCP yield per 10 a due to high level at all growth stages, but non-significant in relation to TDN yield. The DCP and TDN yield resulting from both levels of N increased with advancing of maturity and was greatest at milk stage. (8) The crude protein content was highly correlated possitively with digestibility of crude protein, dry matter and crude fiber, the DCP and TDN content. The crude lignin (CL) content closely related with TDN content and could be predicted from the equation TDN=80.78-1.453 CL (SE of the estimate: 1.87).

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This experiment was carried out to make clear the difference of the productivity between the improved and the natural grassland where chestnut trees were planted. For this purpose two kinds of plot were prepared in 1957. The chestnut seedlings were planted in the spring of 1957, and were grafted in April of 1960. Orchard grass and ladino clover were sown on the improved plot, and the same quantity of fertilizer was applied to the both grassland plots. This paper treats of the results obtained from 1960 through 1962, a part of which was formerly reported. The results are as followes. 1. Before 1960, the herbage yield in the improved grassland plot (I plot) was higher than that of natural grassland plot (N plot). From 1961 on, the herbage yield in N plot was equal to that of I plot on the basis of fresh weight, and the dry matter yield was bigger in N plot than in I plot. 2. The estimated figures show that from 1961 on DCP production in I plot was higher than in N plot and in TDN production two plots were equal. Nutritive Ratio was 3 in I plot and was 9-7 in N Plot. 3. In the feeding experiment on one cow, the difference of FCM yield per day or per acre in the two plots was not so clear. 4. The nut yield of the chestnuts in I plot was about three times as high as in N plot. 5. It can be concluded that the improved grass cover may be favourable for chestnut tree productivity. But from the grassland productivity point of view, the natural grassland may be worth while forfertilizing. Further feeding experiments on such grasslands shall be carried out.

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Several trials (No I-V) were carried out in order to find suitable ways of doing as to area and form of testing place, number of test animals, number of replications of grasses tested and so on, when cafeteria method was adopted for determining palatability of 8 silages using 4 dairy cows. Moreover one trial (No VI) was carried out in order to inspect method for determining order and relative quantities of palatability, when the cafeteria method wat conducted in a way of an omitsystem. And the results were summarized as follows: 1) The degrees of selectivity were compared with each other, when areas of testing place were changed among 25 m^2, 50 m^2 and 100 m^2 per one head and its forms were shifted from square to rectangle in a same area. In both cases of areaand form, they were much similiar among one another. So it was presumed that the area and form of testing place might be flexible following the conditions in practice. 2) The effects of number of test animals on degrees of selectivity were examined through the tests using respectively one, two and four heads in a testing place. Following increase of number of test animals, the differences of the palatability among silages tested became smaller. This was due presumably to mutual restraints among test animals. 3) The results of the tests comparing degrees. of selectivity between 2 and 4 replications of 8 silages in a place using 4 cows, was that with increasing replications the selectivity became more sensitive in a way similiar to the case of decreasing number of test animals. 4) From judging synthetically the effects of both number of test animals and replication of tested grasses, it was deduced that the more test animals and the less replications of tested grasses were suitable when the differences of palatability among tested grasses were expected to be determined roughly by only one test, and in the case expecting the more precise determination only one head of test aminal and as many replications of grasses as possible were desirable. 5) The cafeteria method following the omit-system which elminates successively the grasses exhibiting the highest palatability in each test, had no difficult problem as to the determination of orders. But it had several doubtful ways for determining quantitatively the relative palatability, because they had advantages and disadvantages in each case. The authors studied a way in which the sum of intakes of the most heavily eaten grass and that of other each residual grass would be caluculated as 100, which being shared to each grass following the ratio of intake. In consequence, the relative value of the palatatability of every greass was distributed between 0 and 100, and their mean velue being 50. And it seems likely that these figures show properly the mutual differences of the palatabilities of grasses tested.

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1) The silages and hays of orchard grass, originated from first cut grasses of early, middle and late growth stages and aftermath, were compared with each other on their palatability to dairy cows. 2) The ratings of palatability were in the orders of i) early, ii) middle of first cutting, iii) aftermath and iv) late of first cutting, in both silages and hays. The differences of palatability among them, however, were much clear in hays comparing with silages. This was due presumably to that the palatability of hays was mainly responded to general chemical constituents while the palatability of silages was governed more strongly by the flavours associated with the composition of organic acids produced through fermentation. 3) Judging from these facts, it is deduced that the first cut grass of high quality in early growth stage is much more effectively utilized as hay than as silage, while the grass in late growth stage, which missed the right time to cut, is desirable to be used as silage.

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This experiment was conducted to compare the growth habit of summer forage crops on upland field converted from paddy field with that on general upland field during summer of 1962, 1963 and 1964. The converted upland field was transposed from ddy field in autumn of 1961 after harvesting rice plant. The crops examined were corn, teosinte, Sorgo and NewSorgo. The following results were obtained: 1. There was higher soil humidity in converted upland field than in general upland field. With the progress of growth of crops, the differences of soil humidity between them gradually become smaller near soil surface, but it was kept up successively at the 10 cm depth in soil. The increase in soil temperature was delayed in converted upland field during early season of growth. 2. The early growth of crops on converted upland field was slower remarkably than on general upland field. Therefore, the first cutting produced lower fodder on the former than on the latter. The second and third cuts also produced lower fodder on the former than on the latter in Sorgo and New Sorgo, but produced rather high fodder on the former than on the latter inteosinte. 3. Four crpos produced higher amount of fodder on general upland field than on converted upland field in total of three years, but the rate of decrease of yields on conve rted upland field was different among crops. The rate of decrease in Sorgo and New Sorgo were the greatest (25%), that in teosinte was the smallest (5%) and that in corn was at the middle of them. 4. Roots of corn and teosinte were very winding and developed comparatively near soil surface and roots of Sorgo and New Sorgo were slightly winding and developed comparatively deep in soil.

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Some investigations were conducted to make clear the influence of soils on the growth and leaf structure of alfalfa. Three kinds of typical low productive soil in Hokkaido, namely, heavy clay soil, peat soil and volcanicaash soil were examined. The results obtined were as follows: 1) The plant height was especially short in the volcanic ash soil and peat soil. The plant height in the heavy clay soil was relatively suppressed in early stage of growth and rapidly recovered in later stage. 2) The change in number of plant leaf was similar to that of plant height. 3) The surface area of the leaf was small in all of the soils, especially in the volcanic ash soil and peat soil. 4) The leaf tissue was the thickest in the peat soil and the thinnest in the volcanic ash soil. 5) The size of the leaf cell was increased in the peat soil. 6) From above results, it is suggested that the growth and leaf structure of alfalfa are characterized with the kinds of soil used.

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