Stem length per unit area, the number of rooted nodes per unit area, and the magnitude of root systems etc. were compared among kudzu stands differing in spacing (40,80 and 120cm spacings) just after overwintering (March 1-10). Forty-nine to 60 one-square meter quadrats were placed in the kudzu stands and then stems, crowns and rooted nodes were sampled within each quadrat. Despite greater living stem length per unit area in 120cm spacing than in 40cm spacing, the number of rooted nodes per unit area was smaller in the former than in the latter. These results can be attributed to a higher proportion of rooted nodes to total number of nodes in the closer spacings and a greater number of nodes per unit area in the closer spacings due to a greater number of nodes per unit living stem length. Thinner stems, shorter stem length and smaller number of nodes per plant, and smaller root systems on crowns and rooted nodes were produced in the closer spacings, suggesting that individual plants were smaller due to more severe interplant competition in the closer spacings. These results indicate that a dense network of stems and root systems is formed in the close spacing, but the stem and root system are poorer than in the wide spacing.

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The influence of metabolic inhibitors on the uptake of sodium (Na) was examined by using five herbage species; Rhodesgrass (Chloris gayana KUNTH.), green panic (Panicum maximum JACQ. var. trichoglume EYLES), Italian ryegrass (Lolium multiflorum LAM.), African millet (Eleusine coracana (L.) GAERTN.) and timothy (Phleum pratense L.). Eeach species was grown in culture solution added with sodium azide (NaN_3) or 2,4-dinitrophenol (DNP). Uptakes of phosphorus (P), potassium (K), calcium (Ca) and sodium (Na) were estimated from the residual amount of each element in the culture solution. The results were summarized as follows: 1) The application of NaN_3 strongly inhibited the uptake of P, but less inhibited Ca uptake. The extent of inhibition of Na absorption by NaN_3 varied among species with the following descending order; Rhodesgrass and green panic>Italian ryegrass>African millet and timothy. 2) The influence of DNP on uptakes of P, K, Ca and Na varied among elements. Uptakes of both P and K were strongly inhibited at concentrations above 10^<-5>mol/l DNP and showed even a negative absorption above 10^<-4>mol/l DNP. However, the uptake of Ca was weakly inhibited over an examined range of concentrations of DNP. The uptake of Na by Rhodesgrass and green panic decreased by DNP as was the case of P or K. Also the uptake of Na by Italian ryegrass was inhibited to some extent by DNP. However, for African millet and timothy, the absorption of Na was weakly inhibited by DNP in the same way as Ca. From these results, it was suggested that the uptake of Na had a close relation to the plant metabolism for such herbage species with higher Na content as Rhodesgrass or green panic.

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Rhodesgrass (Chloris gayana KUNTH.), Italian ryegrass (Lolium multiflorum LAM.) and African millet (Eleusine coracana (L.) GAERTN.) were grown in culture solutions without sodium (Na) and potassium (K), and with 1.2me/l Na (as NaCl) or 1.2me/l K (as KCl) for 5 days and evaluated in terms of chlorophyll concentration in leaves, dry weight of plant tops, and constituent and content of nitrogen (N). Following results were obtained; The chlorophyll concentration in leaves of each species increased steadily in course of time after receiving K treatment. The chlorophyll concentration in leaves of Rhodesgrass clerarly increased after reciving Na treatment and reached about 1.7 times as much as that of the Na and K deficient plants by the 5th day. Also the chlorophyll concentration in leaves of Italian ryegrass gradually increased after receiving Na treatment. However, no increase was observed for African millet. Rhodesgrass plants alone showed a distinct increase in dry weight of plant tops by receiving Na treatment. Proportions of ammonia-N, amide-N and amino-N to total-N contents in plant tops of each species decreased by an addition of K. In contrast to this, proportions of nitrae-N and protein-N increased by an addition of K. This tendency was also observed in Rhodesgrass and Italian ryegrass plants which received Na treatment.

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Heat treatments in preparing roughages affect the nutritive value of feed protein. This study was undertaken to elucidate heat damage from a viewpoint of changes in amino acid content. Second cutting Italian ryegrass (Lolium multiflorum LAM.) dried at six levels of temperature (freeze, 40℃, 60℃, 80℃, 100℃ and 120℃) and ensiled at two levels of temperature (20℃ and 60℃) was prepared, and described as dried materials and ensiled materials, respectively. 1. The grand total of free-amino acids showed lower values in the materials dried at higher temperatures; 1.2% at 120℃-treatment as compared with 6.6% at 40℃-treatment. The reduction rate from 40℃-treatment to 120℃-treatment showed over 90% in free-Ileu, -Leu, -Tyr, -Phe, -His and -Arg. In materials ensiled at 60℃, the grand total of free-amino acids increased after ensiling, however, the contents of free-Thr, -Ser, -His and -Lys decreased after ensiling. Free-amino acid pattern similarities among 60℃-, 80℃-, 100℃- and 120℃-dried materials showed high values of about 0.9. The similarities of freeze- and 40℃-dried materials to other materials showed under 0.8. In ensiled materials, the similarities between the materials ensiled at 20℃ and 60℃ showed under 0.7. 2. In dried materials, total-Lys content was the significantly lowest at 120℃-treatment. However, the definite relationship between the rise of the drying temperatures and the changes in total-amino acid contents except for Lys was not recognized. In materials ensiled at 60℃, however, the peculiar declines of total-Ser, -Ala, -Cys, -Ileu, -Tyr, -His, -Lys and -Arg contents were observed. Total-amino acid pattern similarities were shown over 0.9 among almost all of the treatments. 3. Available lysine contents decreased in over 80℃-dried materials and showed the lowest value in 120℃-dried materials and showed the lowest value in 120℃- dried material. In 60℃-ensiled materials, the contents decreased to show under half of the values of pre-wilted grass.

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The objective in a series of our field experiments is to improve the low-input method of pasture establishment by using effectively the tree litter resources. In this report, the effects of litter layers on the establishment and growth of orchardgrass (Dactylis glomerata L.) sown on the cutover land of larch-tree (Larix leptolepis MURRAY) forest without chemical fertilizer was investigated. L, F and H litter layers on the forest floor remained completely in the experimental field just after clear cutting. Weight of fresh litter was 1.47kg DM/m^2 in L and F layers and weight of decayed litter mixed with soil particles was 1.55kg DM/m^2 in H layer. Three different litter layer treatments were applied to seed-bed plots. They were; I: Seeds were sown on the forest floor, removing the all three litter layers. II: Seeds were sown on the H litter layer, removing L and F layers. III: Seeds were sown on the litter layers (without disturbance). Orchardgrass seeds were sown without chemical fertilizer in each plot, one week after seed-bed preparation. Nitrogen mineralization activity of tree leaf litter was also estimated by incubation, in order to evaluate the nitrogen supply in each litter layer. Results are summarized as follows: 1. Litter layers suppressively influenced the emergence of orchardgrass by their physical factors. However, the seedlings established on the bare soil suffered from frost damage due to retarded growth by the low levels of nutrients released from litter layers. The mortality during the winter was much higher in the I Plot compared with the other plots. The population numbers of orchardgrass after 10 months of sowing were 8,260 and 108 plants/m^2 in the Plots I, II and III, respectively. 2. Growth of individual orchardgrass was obviously stimulated by chemical factors of litter layers, so that the maximum weight per tiller after 10 months of sowing was obtained in the Plot III. However, dry matter weight was about 30g/m^2 in both plots II and III due to relatively high population. 3. The amounts of inorganic nitrogen released from tree leaf litter after 8 weeks of incubation were 0.24, 1.18 and 0.30mg/g litter in L, F and H layers, respectively. Those were equivalent to 0.8, 13.2 and 4.7kg N/ha. However, nitrogen mineralization activity of the surface soil was much lower than that of tree leaf litter. Larch-tree forest litter was considered to be useful for the low-input pasture establishment, but their nitrogen effect was evaluated to be relatively low as compared with that of deciduous broad-leaved forest which was investigated in the previous report.

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The mineral status of breeding beef cows from three livestock stations in Tottori, Okayama and Kagawa Prefectures was investigated by evaluating mineral concentrations in diets and blood plasma of cattle. The Na concentrations in diets with the exception of October pasture grass from Tottori and December pasture grass from Okayama were lower than the requirement (0.08%). The P concentrations in the pasture grasses from three stations were as high as the requirement (0.22%) or lower than the requirement. The Ca concentrations in all diets were higher than the requirement (0.28%) with the exception of the supplemented hay from Kagawa showing 0.20%. The Mg concentrations in all diets were higher than the requirement (0.10%). The ratio of K/(Mg+Ca) in July and September pasture grasses from Okayama and April pasture grass and supplemented hay from Kagawa were higher than 2.2. The Cu concentrations in diets were regarded as marginal level ranging from 5.67 to 10.65ppm and the Zn concentrations in diets ranged from 24.9 to 80.2ppm in the three stations. The cows which showed lower plasma inorganic phosphorus (Pi) concentrations than the critical level (4.5mg/dl) were observed each month in all the three stations. The cows which showed plasma Ca concentrations below the critical level (8.0mg/dl) were observed each month in Okayama and in December in Kagawa. One third of the cows from Okayama and a half of the cows from Kagawa showed lower plasma Mg concentrations than the critical level (1.8mg/dl). A half of the cows from Okayama showed lower plasma Cu concentrations than the critical level (0.65μg ml). No cows showed plasma Zn concentrations below the critical level (0.8μg/ml) in any of the three stations. The low plasma Pi and Mg concentrations of cows were most likely due to the low P concentration and the high ratio of K/(Mg+Ca) in diets respectively. In Okayama, material antagonistic to Cu metabolism was suspected to exist in the diet. The relation of Ca concentrations between diets and plasma in Okayama was not clear.

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The authors reported a new ploughless method mainly using new machines. The main improvements of this method were cutting and crushing of native vegetation on the site for preparation of seedbed rich in crushed wood fragments. This method combined using a stumpcutter (SC) to cut stumps with bushcutter (BC) to crush bushes. The basic part of SC was a hydraulic shovel which was ordinarily used as an excavator in civil engineering work. Two scissor-like cutting edges were installed on the bracket part of the excavator in such a was as to be able to open and shut. This cutter was inserted around the stump and cut it. The BC was used to cut and crush young trees and tall bushes. At the same time it stirred the soil about 5cm below the surface, so it also cut and crushed rhizomes and roots of native perennial grasses. The limiting inclinations of operating of SC and BC were about 25 and 30°, respectively. The cutting time of SC was about 2.5min per stump and the total operating time was about 687min/ha. The total operating time of BC was about 35h/ha in the condition of repeated twice treatments. Most of the crushed wood fragments were less than 10cm in length after the treatment. This new method had no process of transferring of stumps, cut-branches and -trunks as well as soils. The altitude and roughness of the ground were almost the same as those established before. There was 581.9mm of precipitation in 29 times during 4 months after the establishment. However, soil erosion and the transfer of crushed wood fragments were not observed. There were no stumps and lines of excluded wood roots in the pasture so that tractor could be used freely.

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Voluntary DM intake, apparent digestibilities and rumen fermentation profiles were measured in diary heifers fed either sorghum silage or foggage ad libitum as the sole feed. The milk production and gross efficiency of two sorghum feeds under a concentrates supplementation were also investigated with three different rations: "0F" (silage 30kg FW), "7.5F" (silage 20kg FW+foggage 7.5kg FW) and "15F" (silage 10kg FW+foggage 15kg FW). The sorghum foggage had lower contents and lower digestibilities of dietary components except for NFE than the silage. The sorghum silage and foggage were identical in terms of rumen pH and VFA concentration, but the foggage gave rise to a much lower rumen ammonia-N level than did the silage. The voluntary intake of DM was 30% lower for the foggage ration in the lactation trial was, however, similar to that value (50.0g per kg W^<0.75>) of foggage in the ad libitum feeding trial with no supplements. Thus, the 3 foggage rations were similar in terms of milk yield and gross efficiency.

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Models describing pasture production are often constructed using a systems approach. However, as most of them contain too many variables to obtain the initial values for the equations for simulation, they cannot be useful for farmers and farmers' cooperatives. To overcome this shortcoming, models using the Logistic equation were developed in this study. Since pasture production depends heavily upon annual and seasonal changes in the meteorological conditions such as daily air-temperature, long-term prediction of seasonal changes in pasture production is difficult. If several typical changes in the patterns of meteorological conditions could be determined, it may become possible to predict roughly the course of pasture production with time for each pattern. In this study, the intrinsic plant growth rate changes in the Logistic equations for six patterns of daily air-temperature conditions wre derived, and aboveground pasture production at the Nishinasuno Area was calculated, as an example, for each of the six patterns.

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This study was conducted to determine an optimum grazing pressure on a temperate grass pasture in the southwest region of Japan. Each paddock was grazed seven times in each of six successive years under two levels of grazing pressure (high: H and low: L) per the amount of available standing crop. Annual total numbers of cattle grazed in H and L were 1368 and 1013 heads/ha and amounts of herbage dry matter (DM) consumed annually were 8174 and 7707kg/ha. The percentages of the amount of herbage consumed to the amount of standing crop were 47-86% in H and 36-62% in L. Herbage DM intakes per day per head (500kg of body weight) in H and L were 4.8-7.3kg and 6.5-9.8kg, respectively. In both treatments, those were high in spring and winter and were low in summer and autumn. The cover of tall fescue kept about 90% during this trial. The number of the grass species counted and the cover of all the grass species except tall fescue in H were a little higher than those in L. But, those in both treatments were almost stable after the second or third year of this trial. The concentration of several nutritive components in herbage differed with height of tall fescue, and the nutritive value was higher in short one. The quality of tall fescue was high in spring and decreased in summer, but it increased again in autumn and winter. Judging from the results described above, the percentages of herbage consumed to standing crop should be 60-70% in spring, 40% in summer, 50% in autumn and 70-80% in winter, though these values may change according to the fertilizer level or the number of rotation. These levels of grazing pressure are thought to be suitable for both animal performance and vegetation maintenance.

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A series of trials has been carried out to determine the level of voluntary intake and digestibility of clipped orchardgrass and alfalfa fed at several growth stages to wethers. The rectilinearity of the relationship between digestible dry matter intake (Y_<DDMI>: g/kg^<0.75>) and voluntary dry matter intake (X_<DMI>: g/kg^<0.75>) : Y_<DDMI>= a+bX_<DMI> and the curvilinearity of the relationship between dry matter digestibility (Y_<DMD>: %) and voluntary dry matter intake (X_<DMI>: g/kg^<0.75>) : Y_<DMD>=b+a/X_<DMI> seem to be the result of certain interrelationships among the potential dry matter digestibility (=b) and excretion of delayed residues flow through gastrointestinal tract (=a). The regression equations are shown below: orchardgrass: Y_<DDMI>=-13.9+0.86X_<DMI>, (r=0.97, P<0.01) Y_<DMD>=85-1352/X_<DMI>, (r=-0.83, p<0.01) alfalfa: Y_<DDMI>=-12.8+0.79X_<DMI>, (r=0.92, P<0.01) Y_<DMD>=79-1292/X_<DMI>, (r=-0.43, p<0.01) The fill of undigested dry matter (UDMF: g/kg^<0.75>) would equal the dry matter excretion added to (a). The rate of passage (Kp) can be represented by Kp=dry matter excretion/UDMF the rate of digestion (Kd) can be represented by Kd=(voluntary dry matter intake-UDMF×Kp)/UDMF Estimated average values of total amount of dry matter present in the gut (fill), Kp and Kd are shown below: orchardgrass: fill=72.4g/kg^<0.75>, Kp=0.62, Kd=1.05 alfalfa: fill=85.2g/kg^<0.75>, Kp=0.70, Kd=1.19

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To investigate the effect of steam treatment on the nutritive value of tropical grasses, mature guineagrass (Panicum maximum JACQ. var. maximum), green panic (Panicum maximum JACQ. var. trichoglume EYLES) and Rhodesgrass (Chloris gayana KUNTH.) were steamed at 170℃ for 30min of 180℃ for 10min, and chemical composition and in vitro dry matter (DM) digestibility of the treated samples were compared with those of the untreated samples. In vitro DM digestibility of the samples was measured by incubation with rumen fluid of goats and pepsin. The results obtained were as follows: Acetyl bromide lignin (ABL) content decreased with 170℃・30min and 180℃・10min treatments and showed little differences between treatments. Silica content tended to decrease with both treatments. In vitro DM digestibility generally increased with both treatments and showed little differences between treatments. ABL digestibility generally tended to decrease by 170℃・30min treatment however it made little changes with 180℃・10min treatment. The recovery of digestible DM showed no decrease in two samples with 170℃・30min treatment and in four samples with 180℃・10min treatment. The result suggested that 180℃・10min treatment was more effective than 170℃・30min treatment for improving the nutritive value of mature tropical grasses by steam treatment.

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To investigate the effect of wet treatment with sodium hydroxide on nutritive value of tropical grasses, mature guineagrass (Panicum maximum JACQ. var. maximum), green panic (Panicum maximum JACQ. var. trichoglume EYLES) and Rhodesgrass (Chloris gayana KUNTH.) were soaked in 0.75 or 1.50% NaOH solution (NaOH/grass: 4.5 or 9.0% in dry weight) at 20℃ for 24hr, and chemical composition and in vitro dry matter (DM) digestibility of the treated samples were compared with those of the untreated samples. In vitro DM digestibility of the samples was measured by incubation with rumen fluid of goats and pepsin. The results obtained were as follows: Acetyl bromide lignin (ABL) content generally tended to decrease with 9.0% treatment however it increased slightly with 4.5% treatment comparing with 4.5% treatment. In vitro DM digestibility tended to increase slightly with 4.5% treatment and showed a significant increase with 9.0% treatment. ABL digestibility tended to increase with treatments and showed a little higher value with 9.0% treatment than with 4.5% treatment. A slight increase in DM digestibility with 4.5% treatment seemed to be caused by the decrease of silica content. The significant increase in DM digestibility with 9.0% treatment was mainly caused by the decrease in contents of ABL and silica and the increase of ABL digestibility. The recovery of DM of all samples decreased with both treatments and showed lower value with 9.0% treatment comparing with 4.5% treatment. The recovery of digestible DM decreased in all eight samples with 4.5% treatment however that of five samples showed no decrease with 9.0% treatment. The result suggested that 9.0% treatment was more effective than 4.5% treatment for improving the nutritive value of mature tropical grasses by wet treatment with sodium hydroxide.

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To investigate the effect of ammonia treatment on the nutritive value of tropical grasses, mature guineagrass (Panicum maximum JACQ. var. maximum), green panic (Panicum maximum JACQ. var. trichoglume EYLES) and Rhodesgrass (Chloris gayana KUNTH.) were treated with anhydrous ammonia (NH_3/grass: 1.5 or 3.0% in dry weight) at 20℃ for 4 weeks, and chemical composition and in vitro dry matter (DM) digestibility of the treated samples were compared with those of the untreated samples. In vitro DM digestibility of the samples was measured by incubation with rumen fluid of goats and pepsin. The results obtained were as follows: Crude protein content increased with both treatments and showed slightly higher value with 3.0% treatment comparing with 1.5% treatment. Acetyl bromide lignin (ABL) content made little changes with 1.5% treatment, however it tended to decrease slightly with 3.0% treatment. Silica content showed a slight decrease with both treatments. In vitro DM digestibility increased greatly with both treatments and showed slightly higher value with 3.0% treatment than with 1.5% treatment. ABL digestibility increased with both treatments. The increase of DM digestibility in each treatment was correlated higher with the increase in ABL digestibility comparing with the decrease in content of ABL or silica. The recovery of DM of the sample made little changes with both treatments, therefore that of digestible DM increased and showed slightly higher value with 3.0% treatment than with 1.5% treatment. The result suggested that 3.0% treatment was more effective than 1.5% treatment for improving the nutritive value of tropical grasses by ammonia treatment.

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Recently, Japanese lawn grass (Zoysia japonica STEUD.) and Zoysia type grassland are again being watched, because of their prominant characteristics as a recreational green for citizens and a low cost grazing pasture for beef cattle. So, some subjects to investigate were discussed from the view point of better use of Japanese lawn grass and Z. type grasslands in Japan, by reviewing the research works on them. The subjects of the research works were divided into nine categories, that is; Classification of Zoysia grasses, Distribution of Japanese lawn grass in Japan, Physiology and ecology of the grass, Germination of seed, Variation and breeding of new cultivar, Establishments of Z. type grasslands, Succession of semi-natural grassland in Japan and the site of Z. type grassland, Productivity and carring capacity of Z. type grass land and Growth of stolen and root in an sloped land. Some conclusions and important subjects to be investigated for the better use of the grass and Z. type grassland in Japan were summarized as follows. 1. Possibility to expand the area of distribution by artificial works and introduction of new cultivars. 2. Investigation of the fundamental physiology of the grass such as differentiation of flower buds. 3. Improvements of the germination rate under natural conditions relating to the establishment of Z. type grasslands. 4. Estimation of characteristics and variation in different areas for the breeding of new cultivar. 5. Developments of the methodes for maintenance of stable Z. type grasslands, including the establishment of a proper degree of pressure (stocking intensity) in Japan. 6. Establishment of the correct method to estimate the carrying capacity and productivity. 7. Establishment of the rotational use of the Z. type grasslands with artificial pasture to improve the productivity and carrying capacity. 8. Fundamental studies on the growth of stolon and root in sloped lands relating to the soil conservation.

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