To clarify the snow endurance in winter annual forage crops through reserve carbohydrate metabolism, storage of nonstructural carbohydrates (NSC) was measured in barley, rye and oats at weekly intervals during fall in the present experiment. Ninety percent ethanol was used to extract mono- and oligosaccharide while fructosans were extracted with 70% ethanol and water. Concentrations of NSC (NSC%), especially of fructosans gradually increased throughout the fall growing season, untill the beginning of snow cover. Regarding with plant parts NSC% was higher in the stems than in the leaf blades and roots. Among the three species, storage of NSC and degrees of polymerization of fructosan were supposed to be superior in the order of rye>barley>oats. Changes in the concentrations of NSC bore a close resemblance to that in the dry matter contents (%). It is considered that NSC as a component of dry matter directly affected the fluctuation of dry matter content.

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To clarify the snow endurance in winter annual forage crops through carbohydrate metabolism, nonstructral carbohydrate (NSC) storage of several species and varieties was investigated in relations to their snow endurance in the present experiment. Twenty-one varieties of oats, barley and rye were used. Concentration and compositon of NSC before the beginning and just after the thawing of snow, and the degrees of damage by snow mold diseases were measured. Results are sumarized as follows. 1) Among the three species, concentration of NSC (NSC%) was the highest in rye, the intermediate in barley and the lowest in oats. The storing capacity of NSC was considered to be higher in the order of oats<barley<rye. 2) NSC% significantly differed among the varieties in each species. The differences was very large in rye, for instance, the NSC% of the highest variety was more than two-fold of that of the lowest one. But the differences were less in barley and very small in oats. Regarding maturity, NSC% of the medium and late maturing varieties were higher than that of the early maturing ones. 3) NSC of the species and varieties were considered to be mainly consisted of low molecular fructosans and lesser amount of sucrose. 4) The species and varieties higher in NSC% before beginning of snow cover were lower in the degrees of snow damage and higher in the NSC% just after the thawing of snow. 5) The storing capacity of NSC seemed to be controlled by genetical factors. The strains having high NSC may be avilable through plant breeding efforts.

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The factors on the seasonal variation of the dry matter production were investigated in the grazed pasture of Agrostis alba. The value of crop growth rate (CGR) varied from -6.0 to 11.4, and it attained its maximum in spring. As CGR was divided into net assimilation rate (NAR) and leaf area index (LAI), the value of NAR varied from -4.2 to 10.2, and that of LAI varied from 0.30 to 4.15. Values of CGR showed a strongly positive correlation with NAR values (r=0.748, P<0.01), but not with LAI values. These correlations in the grazed pasture were the opposite ones in the cutting sward. Values of relative growth rate (RGR), varied from -0.009 to 0.016, were very small, because the ratio of the amount of regrowth to that of the standing crop was extremely small. As the CGR was divided into the growth rate of each plant part (leaf, stem, standing dead and underground part), the values of the growth rate of underground part were highest correlated with CGR values (r=0.729, P<0.01) and secondly, those of leaf were also correlated (r=0.344, P<0.05). Although CGR values did not show a significant correlation with the mean maximum temperature (Mx.T), NAR values showed a negative correlation (r=-0.576, P<0.01), while LAI values showed a positive correlation (r=0.758, P<0.01) with Mx.T. Thus, following equations were obtained. NAR=-0.358Mx.T+8.182 LAI=0.155Mx.T-0.985 They did not show a significant correlation with the mean daily rainfall (RAIN) nor the mean daily solar radiation (RAD), but only NAR values showed negative correlation with RAIN (r=-0.336, P<0.05). Values of the growth rates of underground part and leaf showed a negative (r=-0.354, P<0.05) and a positive correlation (r=0.295, P<0.05) with Mx.T, respectively. As only concerning with the effect of temperature, the dry matter production in the grazed pasture was dependent on NAR in the period of lower temperature and also on LAI in the period of higher temperature within a year.

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The shoot and root growth of tropical pasture plants (nine legumes and nine grasses) and the nodule formation of the legumes were assessed when plants were grown in Red-Yellow acid soil modified by additions of calcium carbonate. The optimal ranges of soil pH for the tropical grasses and legumes appeared as below. They varied significantly among the species tested and showed generally lower pH optima than those for the temperate counterparts. Grasses: buffel grass≒Rhodes grass≒molasses grass (pH 4.5-6.5)<para grass≒Guinea grass≒pangola grass (5.0-7.0)<setaria grass≒star grass≒dallis grass (5.5-7.0). Legumes: Endeavour styo≒Verano stylo (4.5-6.5)<centrosema≒siratro (4.8-7)>lotononis≒silverleaf desmodium≒greenlaf desmodium≒Cooper neonotonia (5.0-7.0)<leucaena (6.2-7>), however, either lotononis or siratro showed wider pH optima for their growth and acid torelance being comparable to those of Endeavour and Verano stylos. Optimal pH ranges for the nodule formation by legumes were in higher values than those for the growth of host plants. The adaptation to the acid soils of the grasses seemd to be derived from the enhanced rates of soil nutrients up-take by the root systems whereas those of the legumes from the extension of the root systems. With the results above, discussions were directed to seeking an econmical liming method in Red-Yellow soils in subtropical Japan.

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Siratro was cultivated in mixture with Guinea grass (Gatton), pangola grass, or setaria grass (Kazungula) and cut every 3, 5, 7, and 9 weeks to 3cm above the ground for two years in Ishigaki Island, subtropical Japan. Dry matter and digestible dry matter yields and the legume percent (Siratro) were measured. Annual total dry matter and digestible dry matter yields of each Siratro/grass mixture tended to increase with longer cutting intervals ; the highest yield with 9 weeks for pangola grass or setaria grass and with 7 weeks for Guinea grass mixed with Siratro. The percent Siratro in the mixture markedly dectined with cutting interval of 3 weeks. Cutting intervals longer than 7 weeks were recommended for exploiting full potential of Siratro in the mixtures. Dry matter digestibilities of the grass species declined with higher temperature and with longer cutting intervals in the following order ; pangola grass<Guinea grass<setaria grass Those of Siratro were less affected by temperature and cutting intervals.

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Sorghum (Sorghum bicolor (L) Moench), Soybean (Glycine max L. cv. Kurosengoku) and Siratro (Macroptilium atropurpureum cv. Siratro) were grown in the field of which soil is derived from granite residual under mono- or mix-cropping system with or without application of fertilizer nitrogen (N). Their dry weights, dinitrogen fixations and N contents in various parts at their successive growth stages were examined to assess the dry matter production in relating with the nitrogen supply status and transference of fixed-N from legumes to sorghum in the mixture cropping. The following results were obtained. 1) The total dry matter yield was not necessaril greater in the mixing cropping. Sorghum was leading species to increase the total dry matter yield the mixing culture regardless of nitrogen application. 2) The dinitrogen fixing activity was consistently higher in soybean than in siratro. That of soybean was remarkably higher under mono- than mix-cropping system during its grain filling period, in contrast, that of siratro was rather slightly higher under the mixthan monoculture cropping system during its corresponding period due to the difference of light condition between them. 3) Total N amount in the plant was the greatest in the mono-culture of legumes regardless of fertilizer-N application. Without fertilizer-N, the total N amount in the mix-cropping was remarkably larger than that of sorghum in the mono-cropping but there was no difference between them with fertilizer-N. 4) The amount of N derived from dinitrogen fixation estimated by the difference method in using N amount of sorghum grown without application of fertilizer-N as a none N_2-fixing system was greater in soybean than in siratro. Proportions of fixed-N transferred to sorghum from soybean or siratro to their whole amount of fixed N were approximately 18 and 15%, respectively.

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In order to clarify the variation of regrowth after cutting and the factors affecting it, fifteen genotypes of tall fescue were examined over a period of thirty days after cutting. In the early stage of regrowth, the number of tillers was of considerable importance, because the genotypes with many tillers had large amounts of carbohydrates available for regrowth due to the photosynthesis of the large residual leaf area and a large volume of stored tissues remaining after cutting. As time passes, however, the tiller size became progressively important, because plants with large tillers showed high rate of leaf elongation.

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Two experiments were carried out to evaluate the loss of volatile matters in sillage during toluene distillation and to correct the error of dry matter determination of silage by the toluene distillation method. In experiment I, the samples of 60 silages made from various materials and with various treatments were subjected to the toluene distillation. The silages consisted of various fermentation qualities and moisture contents. The graduated receiver of the distillation apparatus was designed to collect easily the distillate samples for analytical use. Samples of 50g of chopped silage were accurately weighed into the distillation flask and heated with toluene in apparatus till the distillates became constant volume according to the AOAC method. The volume and weight of distillates were determined and then volatile fatty acids and ammonia in the distillates were analyzed. Volatilites of volatile matters during the distillation were calculated from the amounts of volatile matters present in silages and their distillates. In the silages examined, mean values of percentage volatility of acetic acid, propionic acid, i-butyric acid and n-butyric acid were 58.4, 19.8, 14.5 and 11.7, respectively, ranging from 2.8 to 114.2. The volatility of ammonia during the distillation process ranged from 18.9 to 80.8% with a mean value of 44.5%. Negative correlation was found between the volatility of volatile matters and the fermentation quality or volatile matter concentration of the silages. In experiment II, silage samples of 15 which were made from Italian ryegrass were subjected to the determination of dry matter content by the toluene distillation method. These silages consisted of various fermentation qualities, ranging in the score by FLIEG's method from 10 to 100. The apparatus and procedure for the toluene distillation were similar to those described in experiment I. The samples of distillate were analyzed for individual VFA, ammonia and ethanol. The content of apparent dry matter in each silage by the distillation method was corrected for the amount of volatile matters present in the distillate. The mean values of dry matter content of the silages determined by various methods were 28.21% in oven drying method, 30.17% in uncorrected distillation method, 30.98% in weight-corrected distillation method, 30.75% in volume-corrected distillation method and 30.51% in the method of DEWAR and McDONALD. Significant difference was fond between the dry matter values by the oven drying method and toluene distillation method, whereas no significant difference was shown among the values determined by each distillation method. From these experiments, it was confirmed that the considerable loss of dry matter owing to the volatility of volatile matters in silage could occur during toluene distillation and the error of dry matter determination could be corrected accurately by the determination of volatile matters in distillate.

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An experiment was conducted to find the drying method of analytical sample for the accurate evaluation of nutritive value of silage. Silages used for the experiment were made from Italian ryegrass without additive (C-silage), with 0.4% formic acid (F-silage) and with 1% glucose (G-silage). The silages were fed individually to 3 wethers by a 3×3 Latin square design for digestion trials. On the other hand, the silage samples of analytical use were treated as follows: freeze dried at a 5 micron pressure for 24 hours and then ground in a Wiley mill to pass a 0.5mm screen (F); oven dried with forced air at 60℃ for 8 hours and then ground in the Wiley mill to pass the 0.5mm screen (L); oven dried with forced air at 100℃ for 8 hours and then ground in the Wiley mill to pass the 0.5mm screen (H). Residual mosisture in freeze dried samples was determined by vacuum drying to constant weight over P_2O_5 at 40℃ at a pressure of less than 20 microns (V), while the moisture in oven dried samples was determined by oven drying to constant weight at 105℃ (O). The chemical composition of these samples was determined by proximate analysis and the apparent digestibility of the silages was calculated from results of the trial and analysis. Furthermors, in vitro digestibilities for the dry matter and crude protein of each sample were determined by artificial rumen method and WEDEMEYER method. Resultant silages had different fermentation qualities and contained various amounts of organic acids, ammonia and ethanol according to treatments at the ensiling. The contents of dry matter, crude protein, crude fat and nitrogen free extract (NFE) were appreciably higher in the silages dried by FV method than in the silages dried by LO and HO methods. Digestibilities of dry matter, crude protein, crude fat and NFE determined by wethers were significantly higher in FV dried silages than those in oven dried silages. Such tendencies were detected in the in vitro digestibilities of dry matter and crude protein. The values of digestible crude protein (DCP) and total digestible nutrients (TDN) of the silages evaluated by FV method were significantly higher than those evaluated by oven drying methods. And further, these nutritive values by LO method were higher than those by HO method. The results may show that the FV method is more advantageous to the oven drying methods for the accurate evaluation of nutritve value of silage.

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The present experiment was undertaken with a ^<15>N ammonia tracing technique to examine the effects of various carbohydrates and two kinds of lipid materials on the release of ammonia from the grass nitrogen constituents by rumen microorganisms and on the microbial ammonia incorporation simultaneously occurred, under the condition of non-steady-state of ruminal ammonia concentration in vitro. The strained rumen fluid, obtained from a goat fed on alfalfa hay, was incubated with freeze-dried Italian ryegrass and (^<15>NH_4)_2_SO_4 solution for 90min. Compared with control incubation (without additives), the addition of all of carbohydrates used and corn oil did not vary the quantity of ammonia release from the grass nitrogen. Corn 'oil foots' exceptionally lowered it. The effects of carbohydrates and lipid materials on the microbial ammonia incorporation were as follows: In the case of polysaccharides, xylan and inulin increased appreciably the microbial ammonia incorporation. Xylan was the most effective one. Cellulose showed no effect while corn starch and pectin showed a little effect. Among the disaccharides used, cellobiose was superior to maltose while sucrose and trehalose showed a little effect. Among the monosaccharides supplied, galactose, arabinose and xylose were more effective than glucose, mannose and fructose. In the two lipid materials, corn oil had no effect while corn 'oil foots' tended to lower the microbial ammonia incorporation. From these results, it was concluded that the certain carbohydrate which was effective on lowering the ruminal ammonia production was not functioning as a depressor of the ammonia release from grass nitrogen by rumen microorganisms but was functioning as a stimulator of microbial ammonia incorporation simultaneously occurred. On the effect of corn 'oil foots', it was indicated that the material not only depressed the ammonia release but also lowered the microbial ammonia incorporation.

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It has widely been recognized that lucerne is the most suitable crop for the preparation of leaf protein concentrate (LPC) in temperate region. But in the southwest part of Japan as the Shikoku District, Italian ryegrass grows vigorously in autumn and spring seasons with high protein contents in young leaves. So, it was expected that ryegrass might be rather superior to lucerne as the material crop for LPC production. To prove the above supposition, LPC yield from lucerne was compared with that of Italian ryegrass from October, 1983 to June, 1985, where lucerne was successively harvested from that sown in October, 1983, while ryegrass was sown again in October, 1984.

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