The growth and responses to nitrogen (N) fertilization were investigated in timothy varieties with different heading stages in Konsen district of Hokkaido. Three timothy varieties were used in this experiment ; Kunpu (K, extremely early variety) for use of three cuts, Nosappu (No, early) and Hokushu (H, late) for use of two cuts. Each of those varieties was established as pure swards. Results obtained were summarized as follows : 1. Comparing growth among three varieties, K was similar to No, but H was different from both K and No. Namely, the prostrate type H was longer in plant length and had more number of tillers at 1st cutting. 2. H showed the highest yield of 1st cutting and total yield per year among three varieties. This could attribute to longer growing period for H under the optimum temperature during the 1st growth. 3. H showed lower proportion of heading tillers to all tillers and had more elongating tillers than the others varieties. In spite of late variety, H was similar to K and No in TDN content (about 56%) at the 1st cutting. This accouted for partly by differences among varieties in composition of tillers. 4. Dry matter yield of three varieties increased with the increasing application rates of N fertilizer. H required more amounts of N for obtaining the highest yield. Also, luxurious absorption of N at the 1st cutting stage was observed from about 1.3% in N concentration for K, about 1.5% for No and about 1.8% for H. When each of grasses had the same N content by percent, the highest dry matter yield was obtained in H. These were seemed to be the causes leading high yield of H. 5. From the above results, the longer growing period under the optimum temperature and the higher dry matter yield on condition of the same N content were considered to be an important factors affecting in high yield of Hokushu (late variety of timothy) in Konsen district of Hokkaido.

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The aim of this paper is to show the morphology of macropores of water-retention and drainage in the root zones under the chestnut soil of the Inner Mongolia semidesert steppe in China. The structure of macropores was studied three-dimensionally by examining the physical condition of the soil, the morphology of macropores by X-ray and contrast media. Soil samples were collected from four soil layers of the rootzone shallower than 60 cm in a natural range. The physical condition of each soil layer was sandy soil, dense and solid, and the solid phase rate was 51-55%. The morphology of macropores were classified by each soil layer. First soil layer (0-10cm) formed by wavy shape on the basis of cracks, insect burrows, pores formed by roots, and pores outside of the particles and aggregates. The second soil layer (10-15cm) to the fourth soil layer (55-60cm) consisted of pores formed by roots, and pores outside of the particles and aggregates. Macropore of the drainage zone (pF≦1.5) originated from cracks, insect burrows, and pores formed by roots. But macropore of the water retention zone (pF 1.8, pF 2.0) was shaped by pores formed by roots, and pores outside of the particles and aggregates. The above results of the pore morphology in the chestnut soil show that almost all were shaped by the pores formed by roots, the same as that described for the Andosole case. Accordingly, tubular root pore which originates from the grass roots played an important part in the macropore forms of the grassland soil.

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For better utilization of forage as a protein source in ruminants, red clover (Trifolium pratense L.) was ensiled with chemicals and stored at 20℃ for 50 days to make formic acid・formaldehyde treated silage (FFS), formic acid・tannic acid treated silage (FTS) and ethyl alcohol treated silage (AS), and their protein degradation characteristics in the rumen were compared with that of control silage (CS). Both formic acid and formaldehyde were added to red clover at 0.25% weight on fresh matter basis, tannic acid at 2.5% and ethyl alcohol (50% in concentration) at 8.0%. Silage protein degradability in the rumen was measured using a nylon bag technique with three Tokara goats fed on alfalfa hay and concentrate in the ratio of 8 to 2. Essential amino acids (EAA) composition was determined for herbage, silages and their undegraded residues after 24 hr incubaion in the rumen. The residual protein after ruminal incubation was digested with pepsin-pancreatin solution to estimate the digestion of rumen undegradable protein in the lower digestive tract. The results obtained were as follows : 1. The ratio of protein nitrogen (PN) to total nitrogen (TN) in silage was higher with FFS and FTS than in AS and CS. The ratio of ammonium nitrogen (AN) to TN was lower in chemicals-treated silages compared with CS. These results were due to the depression of protein degradation by chemicals during storage for making silage. 2. Silage crude protein degradability with 24 hr incubation in the rumen was lower in chemicals-treated silages than in CS. Degradability of true protein in the rumen decreased in the order CS, FFS, AS and FTS, which was caused by the chemicals. There were little or no differences in the ratio of EAA to total amino acids between silages and their residues after 24 hr incubation in the rumen, and this observation suggested that EAA composition of silage protein after incubation in the rumen was similar to that of undegraded residual protein digested in lower digestive tract. 3. After 24 hr incubation of silage in the rumen, the digestibility of residual protein with pepsin-pancreatin had higher value in chemicals-treated silages compared with that of CS, in which it was suggested that chemical treatment for silage could have better effect for bypass protein from rumen. The results described above suggested that ensiling forage with chemicals resulted in the depression of silage protein degradation during storage and in the rumen, and therefore contributed to the increase and better use of bypass protein in the lower digestive tract of ruminants.

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Three experiments concerning rumen degradation (Expt 1) and rumen fluid (Expt 2) characteristics and rumen retention time (Expt 3) were conducted to examine the physical effect of steamed larch as a roughage using sheep. In Expt 1, the degradability of larch treated with steam under different treatment conditions, 10, 12.5 or 15 kg/cm^2 of steam pressure for 20 min, and 5, 10, 15 or 20 min of treatment time at 10 kg/cm^2, was measured according to both polyester bag technique (in situ) and incuation method with cellulase (in vitro). And barch steamed at 10 kg/cm^2 for 20 min was used as a control. Samples of each larch preparation were incubated in polyester bags in the rumens of three sheep for 8, 16, 24, 48, 72 and 96 h to estimate potential degradability and degradation rate using the expression p = a + b (1 - e^<-ct>) where p is degradability at time t and a, b and c are constants. In Expt 2, the rumen fluid characteristics, being pH and volatile fatty acid concentration, were measured using three diets containing steamed larch at 10 (W-10), 20 (W-20) or 30% (W-30) levels, and two diets containing orchard grass hay at 30 (H-30) or 10% (H-70) levels as the control. And in Expt 3, W-10, W-20 and W-30 diets and H-70 diets as a control were used for the measurement of the ruminal outflow rate and rumen retention time. The data were described using the equation y = Ae^<-kl(t-TT)> - Ae^<-k2(t-TT), in which Cr (chromium mordanted fibre) marker concentration (y) and faeces sampling time (t) were fitted, where TT, k_1^ (1/k_1) and k_2 (1/k_2) are time for first appearance of marker or transit time, ruminal outflow rate (rumen retention time) and hindgut passage rate (hindgut retention time), respectively. Consequently the total mean retention time (TMRT) is TT + 1/k_1 + 1/k_2. The results obtained were as follows : 1) Expt 1 : Treatment with steam had little or no effect on the both degradabilities in vitro and in situ of larch irrespective of treatment condition. In contrast, the degradability in vitro and potential degradability in situ (a + b) of steamed barch markedly increased from 13.5 to 46.6 and 11.3 to 80.6%, respectively. 2) Expt 2 : The mean value of the rumen fluid pH was the highest 6.55 in W-30 feeding, showing higher value than that of both H-30 or H-70. Acetic/Propionic acid ratio for steamed larch feeding ranged from 2.03 (W-20) to 2.75 (W-30) and W-30 was between H-30 and H-70. 3) Expt 3 : There were significant differences in 1/k_1 and 1/k_2 between the various steamed larch feeding. The 1/k_1 decreased significantly with increase of the proportion containing steamed larch, W-30 having the shortest time of 42 h. But for H-70 the time was 26 h. On the contrary the 1/k_2 increased significantly with increase of proportion of steamed larch. This value was shortest also for H-70. Consequently the TMRT was the short for W-20 and W-30 diets, but about two times longer for H-70. 4) It is concluded that steam-treated larch can not be used as an energy source for ruminants but is likely to have a sufficient physical effects as a roughage at even low containing level of 30% in diet.

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Eleven strains of adley were harvested three times a year in order to obtain maximum foliage yield. Harvested foliage were divided into green juice and pressed cake by pressing them with a twin roll screw press with the aim of using the former as a health food and the latter as a roughage. The strains were divided into early and late maturing types and the latter was superior to the former in both foliage and green juice yields. Okayama, a Japanese domestic strain, was selected from the late maturing strain and used for the further study of three years. The best seeding time for Okayama was May 10th and April 20th and May 29th were too early and too late, respectively, for obtaining as much foliage yield as possible. Three harvesting per year gave 1ton/a fresh yield and 500-600?/a of green juice. The green juice contained 4% dry matter. About 25% of the dry matter in green juice was lost during the spray drying process. The spray dried green juice contained about 20% crude protein, 40% nitrogen free extracts and 35% minerals. For shortening the drying time, green juice was heated, settled, and only the precipitate was dried. By discarding the liquid portion, the yield of the powder was reduced by 70% but the crude protein content of it was nearly doubled because of the great reduction of the mineral content. Green juice containing 6.4kg of dry matter was recovered from fully matured forage with 25.5kg of seed per are.

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Two experiments were conducted to confirm the response to serum mineral concentrations in sheep which have grazed on pasture comprised of different orchardgrass cultivars. Experiment 1 was conducted in order to compare four orchardgrass cultivars with the other species, and Experiment 2 was to compare two orchardgrass cultivars. In Experiment 1, mineral concentrations of forage were significantly different among orchardgrass cultivars in Ca, but not in N, P, K and Mg. Yatugane perennial ryegrass indicated the highest Ca concentrations followed by Hokuryo tall fescue and four orchardgrass cultivars. Among orchardgrasscultivars, Okamidori had the highest value and Akimidori the lowest. When serum in sheep was compared based on the changing values between the first and the last day of the grazing period, there were significant differences among grass cultivars in K, Ca, and Mg. For all of K, Ca and Mg, the changing values were positive for cv.Okamidori, but negative for cv.Kitamidori. In Experiment 2, there were significant differences between cultivars in N, K, Ca and Mg for forages, and cv.Okamidori was higher in these minerals than cv.Akimidori. The changing values of serum minerals were considerably higher in sheep grazing on pasture comprising cv.Okamidori for total protein, Ca, Mg and Cl than those grazing on cv.Akimidori, although the differences were not significant. The difference of some mineral concentrations seen between orchardgrass cultivars was important enough to affect serum mineral concentrations in sheep.

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In order to clarify the ecological situation of broadleaf dock (Rumex obtusifolius L., Rx in the following), an aggresive weed in sown patures, vegetations in 15 pastures of 8 farms have been surveied. The following results have been obtained. 1) The surveied pastures were classified into 3 groups according to abundance of frequency of Rx, namely less than 1096, 11-20% and more than 21% and these were disignated as the low group, the medium group and the high group respectively. 2) Frequency of species appeared in these pasture groups were compared. Echinochloa crus-galli, which occurred abundantly in the high group pasture, had a high positive cor relation coefficient with Rx, whereas orchardgrass, tall fescue, red clover and Artemisia princeps, had a high negative correlation coefficient with Rx. 3) Rx grew thickly in pastures situated in the low land and the pasture where a large amount of farmyard manure was applied. These results indicated that Rx occurred abundantly in the sites fertile and high moisture where Echinochloa crus-galli is common but Artemisia princeps is unusual. 4) Few Rx occurred in the new pastures which had been only several years after establishment, but abundant Rx occurred in the old pastures which 10-20 years had passed since establishment. 5) It is concluded from these results that Rx invade into sown pastures rather slowly and that it grow luxuriously replacing Orchardgrass and tall fescue, etc. after more than several years since pasture establishment. 6) It is discussed how ecologically control Rx and the followings are pointed out ; maintaining the grass stand healthy, avoiding pasture condition tends to be eutrophic excessively and eradicating Rx in the early stage of invasion.

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The association of Z. japonica and D. glomerata is useful for a low-input and stable pasture for beef cattle grazing in the mountaneous area of Japan. The methods of the association establishment and management were studied from an ecological view point. Seeds of Z. japonica, D. glomerata and several weed species which generally appeare on a secondary sere in Japan were oversown without tillage on the cutover land of deciduous broad-leaved forest in Sep., 1980. The three different amounts of chemical fertilizers were applied to the treatment plots (the non, low and high fertilized plots) every year. The vegetations in each of three treatment plots were grazed by beef cattle for 5 years. This report presents the effect of fertilization on vegetation changes under the grazing condition. The results obtained are summarized as follows : 1) D. glomerata established well and grew vigorously in the all plots. The dominancy of D. glomerata lasted for 5 years under grazing condition, although it declined slightly in the non fertilized plot in the last year. 2) Z. japonica expanded the plant cover year by year in the non fertilized plot. However, it stopped expanding the cover in the low fertilzed plot, and disappeared in the high fertilized plot in the second year. Thus the favorable association, which had the equilibrium of coveage between Z. japonica and D. glomerata, was constructed only in the non fertilized plot. 3) The sown weed species which occured frequently in the non fertilized plot were Setaria lutecens and Echinochloa Crus-galli in the first year after start of grazing, and Miscanthus sinensis after the second year. These species were capable to use the indicator plants to succeed in the establishment of the favorable association, because their occurences were not evident in the other plots. 4) Both of the stability in vegetational composition and the high diversity in plant species were shown in the low fertilized plot. The importance of this result was emphasized concerning with the possibility to increase the herbage production of Z. japonica -D. glomerata association in the non fertilized plot by the low fertilization.

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The herbage productivity, chemical composition and in vitro dry matter digestibility (IVDMD) of guineagrass (Panicum maximum JACQ. var. natsukaze), green panic (P. maximum JACQ. var. trichoglume EYLES), colored guineagrass (P. coloratum L.) and rhodesgrass (Chloris gay ana KUNTH var. katambora) under a seasonal 3-cut regime and during regrowth were examined. Guineagrass was the highest yielding species and colored guineagrass was relatively low yielding. The total DM yield of the 3-cuts amounted to 330, 226, 220, and 197kg/a, for guineagrass, green panic, rhodesgrass and colored guineagrass, respectively. The DM yields of guineagrass, green panic and colored guineagrass relative to rhodesgrass, which was a control, were 150, 103, and 90%, respectively. The crude protein content ranged from 8.3 to 14.2% ; colored guineagrass consistently had the highest values. The ranking of mean crude protein content was : colored guineagrass > green panic > rhodesgrass > guineagrass. However, due to the superior performance of other species in terms of DM yield, the ranking order of crude protein yield was : guineagrass > green panic > colored guineagrass > rhodesgrass. Colored guineagrass which gave significantly lower yields of fresh and dry matter, had the highest IVDMD at each cutting. Guineagrass maintained the highest DM yield throughout the regrowth period, whereas the crude protein content and IVDMD, especially at very advanced stage of regrowth, were relatively low. During regrowth, high and negative correlations were found between the cell wall constituents and IVDMD. To obtain a reasonable balance between yield, crude protein content and dry matter digestibility, cutting after 4 weeks may be the best cutting interval for these species. The herbage yield of the panic grasses, especially guineagrass, compared favorably with rhodesgrass. The suitability of these species for making hay and silage, and evaluation of their nutritive value as a ruminant feed are essential and remain to be considered.

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The percentage of each of the three germinating types and adhering strength of coleorhiza hairs in tall fescue were measured to determine the effects of leaf litter forms (slightly decomposed leaf litter and humus layers) and leaf ash layers on germination and establishment of surface-sown grass seeds. The germination characteristics were also investigated on the leaf litter forms of two tree spesies (Japanese red pine, white oak). 1. The rate and percentage of germination of surface-sown tall fescue seeds were high with all of the leaf litter forms and leaf ashes two tree species. The percentage of germination reached over 75%, even on the surface of leaf litters. The germination values on the hnmus and ash layers were similar to those of seeds sown on the soil surface. 2. All types of leaf litter layers, however, increased the percentage of the exposed-root type on the germinating behavior, although the decomposed matter increased slightly the percentage of the rising type. 3. The adhering strength of coleorhiza hairs of tall fescue seed sown on the humus layers was high under the hard conditions of the surface ; the values at the hardness value of 4 g as measured by the silk needle method, was 1.04g with Japanese red pine and 0.47 g with white oak, whereas these values under the hardness value of 1 g was 0.38 g and 0.12 g, respectively. Thus, the percentages of the lying and rising types were raised under the hard surface conditions of the humus layers. 4. Seed pressing was effective to increase the adhering strength of coleorhiza hairs when seeds sown on the humus and ash layers, and improved the germinating behavior.

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