A pot experiment was conducted to evaluate the effects of nitrogen fertilization on dry matter production, nitrogen uptake and nitrogen fixation in mixed culture of forage sorghum (Sorghum bicolor) and soybean (Glycine max). Three nitrogen fertilization treatments were provided as follows : ON ; supplied N-free nutrients solution through the experimental period, SN ; supplied N nutrients added solution for the first one week and then N-free nutrients solution until the end of experiment, TN ; supplied N nutrients added solution through the experimental period. All the treatments were conducted in respective pure cultures and 1 : 1 mixed culture. The dry matter yield of sorghum was highest at TN, on the other hand, that of soybean showed the highest value at SN both in pure and mixed culture. The relative yields for dry matter of sorghum and soybean in the mixed culture were over about 0. 5 respectively and the highest values were 0.64 at TN for sorghum and 0.79 at ON for soybean. Relative yield total was higher than 1.0 at each treatment, and its value was higher at ON than at SN and TN. Nodule formation and nodule activity (acetylene reduction activity) of soybean were stimulated at SN, and remarkably depressed at TN in both pure and mixed culture. Nodule formation and nodule activity in mixed culture increased at ON and SN than in pure culture, but this trend to increase in mixed culture was not obvious at TN. Nitrogen content of sorghum showed the highest value at TN, and that of soybean was the highest at SN in both pure and mixed culture. Nitrogen contents of sorghum and soybean in mixed culture showed a little higher value than in pure culture. The higher relative yield total for nitrogen than that for dry matter suggested that the mixed culture utilized nitrogen in'fixed, soil and fertilizer efficiently comparing to the respective pure cultures.

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Some observations were made on the excreting behavior of Holstein heifers on bahiagrass (Paspalum notatum Flugge) pasture in relation to nutrient recycling, at Miyazaki Animal Industry Experiment Station, Takaharu, Miyazaki. A resting place (about 60m^2) with shading trees was provided in adjacent area to the bahiagrass pasture (1760m^2) to shelter the herd (21-24 heads) in hot days. The pasture was grazed eight times in 1983 and the numbers of defecations and urinations on the pasture and on the resting place were counted separetely through 24 hrs for 5th (26-29, JuD, 7th (23-25, Sep.) and 8th (26-28, Oct.) grazings. The results obtained are summarized as follows : 1) The air temperature in the 5th grazing exceeded 27℃ through almost all of the daytime, and that in the 7th grazing exceeded 27℃ for 5 hours (10 to 15 h). But, the air temperature in the 8th grazing did not exceed 23. 5℃ even at maximum. 2) The numbers of defecations (No./head/day) were 6.5, 8.3 and 7.7 for 5th, 7th and 8th grazings, respectively. The number of urinations (No./head/day) varied with seasons, showing 18.3, 16.8 and 10.7 for the 5th, 7th and 8th grazings, respectively. 3) Percentages of defecations on the pasture (number of defecations on the pasture/total number of defecations) in the 5th and 7th grazings were 74 and 71%, while that in the 8th grazing was 89%. 4) Percentages of urinations on the pasture were only about 50% in the 5th and 7th grazings, though 89% was recorded in the 8th grazing. 5) About 68-76% of defecations and 80% of urinations occurred in the daytime (from sunrise to sunset). 6) The results suggest that existence of a resting place tends to disturb the nutrient recycling by decreasing the excreta deposited on the pasture, especially during the periods of high air temperature in the daytime.

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In well-managed pastures, grasses produce their seeds mainly in the dung patches. Seed production and its efficiency of timothy were examined in the dung patches of the timothy dominant pasture, which was located in Alpine Region Branch of National Grassland Research Institute at 1,000-1,260 m in Central Japan. Twenty-one dung patches were examined. The numbers of panicles and seeds per patch were few, 8 and 160 in average, respectively, with seed productive efficiency of 7.4% in average at panicle level. The considerable variations in the number of panicles and the number of seeds were observed among the patches. The frequency distributions of seed number and seed production efficiency were L-shaped at panicle level. Micro-scale spatial variations of seed production and its efficiency were examined in the quadrat (5×5m) set up in the pasture. Seeds produced occurred extremely locally, and its efficiency was rather high in the areas with higher panicle density of the neighbours. These results revealed that seed production and its efficiency of timothy were low in the dung patches, and suggested that most of seeds produced were originated from the mating events among the neighbours.

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To evaluate the potential of the tropical pasture legumes for increasing pasture productivity in the Northen parts of South-Western Islands of Japan, dry matter yields of nine tropical legumes were compared in relation to the prevailing temperature and rainfall conditions under forty days clipping interval for the last two years of the four year's experimental periods. Also N yields and N concentrations of the tops in pures or in mixtures with Rhodesgrass were compared each other or with pure Rhodes grass applied with four levels of N fertilizer. The legume species used in the experiment were ; Desmodium intortum cv. Greenleaf, D. uncinatum cv. Silverleaf, Neonotonia wightii cvs. Cooper and Tinaroo, Trifolium semipirosum cv. Safari, Macroptilium atropurpureum cv. Siratro, Centorosema pubescens, and Stylosathes guianensis cvs. Schofield and Endeavour. Annual dry matter yield of each legume was as follows ; Greenleaf 1141 kg, Siratro 895 kg, Tinaroo 844kg, Cooper 807kg, Silverleaf 638kg, Safari clover 462kg/10a in pures and Siratro 1271kg, Cooper 1223kg, Greenleaf 1173kg, Tinaroo 1084kg, Silverleaf 1021kg, Centoro 1017kg, Safari clover 960kg/10a in mixtures. These results with higher percent legume in the mixtures suggested that Greenleaf, Cooper, Tinaroo and Siratro were promising for growing in the northern parts of South-Western Islands of Japan. The reasons for the increased dry matter yield of Siratro seemed to be in its wide range of optimal growing temperature and higher drought tolerance, resulting in higher growth rate both in cool and hot/dry seasons. Siratro has shown either higher nitrogen concentorations in the plant tops or enhanced mixture effects for increasing N yields, amounting to 33kg/10a per annum. N yield of Greenleaf was higher in pure than in mixture mainly due to the increased dry matter yield. Those yields were higher than those of Tinaroo and Cooper which dry matter production decreased during hot and dry seasons.

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Most of the legume crops need adequate fertilization to maintain high herbage yields. 'Whey' a by-product in alfalfa leaf protein production pilot plant was utilized as a fertilizer in irrigation. The effect on seed germination, plant growth and root nodule development in legume crops like cowpea (Vigna sinensis L.), green gram (Phaseolus aureus Roxb.) and groundnut (Arachis hypogea L.) were studied in laboratory and glasshouse conditions. In laboratory, seed germination and root length were decreased as the concentration of whey increased. However, a slight increase in shoot length was observed at 10% concn. (diluted 10 times) of whey. Inhibitory effects at higher concentrations of whey were also confirmed in glasshouse. Cowpea and groundnut were not so affected by being whey supplied at 20%, but green gram was damaged. It is observed that, higher concentrations of whey caused growth retardation, plant damage or death. Probably 10% or below concentration of whey and less number of applications would be useful as a fertilizer in irrigation.

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Digestion trials using wethers were conducted for three silages (C : Untreated, G : 3%-glucose added, W : Wilted) and hay made from Italian ryegrass at heading stage. Dry matter concentration in each sample fed to wethers was determined by the six methods of gas chromatography (GC), freeze dry (FD), toluene distillation (TD), corrected toluene distillation by DEWAR and McDONALD method (CTD), oven dry at 70℃ (LOD) and oven dry at 105℃ (HOD). Dry matter digestibilities of the silages and hay based on the individual methods were calculated from the results of the digestion trials and dry matter determinations. Furthermore, DCP and TDN of these samples estimated by wethers were corrected for the dry matter levels determined by the different determination methods, respectively. The values of dry matter content and dry matter digestibility in the silages evaluated by GC method were significantly higher than those by the other methods, whereas the tendencies were not detected in the hay. No significant differences were found among these values evaluated by FD, TD and CTD methods. In addition, the values in the silages evaluated by LOD and HOD methods were significantly lower than those by the other methods. On the other hand, it was indicated that the estimated nutritive value of silage was influenced considerably by the methods for determining dry matter.

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An experiment measuring chemical composition, in vitro dry matter digestibility and digestible energy of harvested and unharvested parts of herbage was carried out to study selective grazing of goats on Siratro (Macroptilium atropurpureum) and Rhodes grass (Chloris gay ana) pastures at 23 and 63 days of regrowth using two oesophageal fistulated male goats. Proportion of leaf and stem of herbage cut at similar harvesting height by the goats grazing Siratro and Rhodes grass and of extrusa from oesophageal fistulae of the goats was also measured. Additionally dry matter intake per bite (DMI/TB), digestible dry matter intake per bite (DDMI/TB) and digestible energy intake per bite (DEI/TB) by the goats were estimated. The results obtained were as follows : 1. Oesophageal fistulated goats selected the part with higher crude protein content, in vitro dry matter digestibility and digestible energy, and lower cell wall constituents of Siratro and Rhodes grass at 23 and 63 days of regrowth. 2. Leaf percentage of extrusa from oesophageal fistulae of goats grazing Siratro and Rhodes grass was higher than that of herbage cut at similar harvesting height by the goats at 23 and 63 days of regrowth. 3. Goats grazing Siratro at 63 days of regrowth had larger DMI/TB, DDMI/TB and DEI/TB than when grazing at 23 days of regrowth. However the animals grazing Rhodes grass at 63 days of regrowth had smaller figures of above mentioned items than when grazing at 23 days of regrowth. The largest DMI/TB, DDMI/TB and DEI/TB were shown at 63 days of regrowth of Siratro and their figures were 0.078g, 0.050g and 0.211 kcal respectively. From the results of this experiment, goats tended to show selective grazing on Siratro and Rhodes grass pastures and they had larger DMI/TB, DDMI/TB and DEI/TB on mature Siratro, though the dry matter yield of Siratro was smaller than that of Rhodes grass at their mature stages.

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It was studied on three straight subdivisional fence lines to grasp the effects of props. These lines are situated from the north to the south on the slope in the public pasture of highland, Tohoku district, and are located at about right angle to the contour line. All of the line posts, ragardless of existence of props, were tipped toward to the slope at maximum angle of 9 degrees and were fallen to the leeward during wintertime at maximum angle of 6 degrees. It seems that the load of snow on the slope acted mainly on the line posts and the barbed wire directly. After acting the horizontal load of 20 kgf, not occoured a strain in the barbed wire, on the top of line posts, the deplacement of posts without props was larger rather than them with props. But its deplacement without props was merely 5.5 cm at maximum and it was not troublesome for the fences. From these surveys, it is suggested that there is no necessity for the subdivisional fences to fix props on the slope at about right angle to the contour line. If need be from the view point of the slope and the soil bearing capacity, it had better to drop the bigger line posts instead of props.

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Chromosome numbers were determined from pollen mother cells (PMCs) in 13 strains belonging to four species and two varieties of the genus panicum. Meiosis was also studied from PMCs in six strains representing three species and two varieties of this genus. 'Morocco' of P. antidotale Retz. and 'South Africa' of P. laevifolium Hack, were diploids (2n=18). Three strains, 'N 780', 'cv. Bambatsi' and 'cv. Burnett', of P. coloratum var. makarikariense Goossens were all tetraploids (2n=36). P. coloratum L. exhibited two ploidy levels ; 'CPI 16794' and 'CPI 17446' were tetraploids (2n=36), and 'cv. Solai' and 'PI 319485' were hexapoloids (2n=54). 'Morocco' and 'cv. Gatton' of P. maximum Jacq., and 'cv. Petrie' and 'N 561' of P. maximum var. trichoglume Eyles were tetraploids (2n=32). Meiotic chromosome behavior was regular in 'South Africa' of P. laevifolium, 'CPI 17446' of P. coloratum and 'cv. Bambatsi' of P. coloratum var. makarikariense. 'Cv. Solai' of P. coloratum showed a slightly irregular chromosome behavior in meiosis with a quadrivalents at metaphase I. Meiotic chromosome behavior was irregular in 'cv. Gatton' of P. maximum and 'N 561' of P. maximum var. trichoglume with frequent quadrivalents at metaphase I and two lagging chromosomes in several cells at anaphase I. Self- and open-pollinated seed sets were studied in eight strains belonging to three species and two varieties of the genus Panicum. In the strains of P. coloratum and P. coloratum var. makarikariense seed sets ranged from 2.0 to 7.1% under self-pollinated conditions and 50.8 to 64.0% under open-pollinated dondition. On the other hand, in the strains of P. laevifolium, P. maximum and P. maximum var. trichoglume seed sets ranged from 28.9 to 52.9% under self-pollinated conditions and 53.6 to 86.9% under open-pollinated conditions. These results indicate that the strains of P. coloratum and P. coloratum var. makarikariense are sexual and self-incompatible, and those of P. maximum and P. maximum var. trichoglume are probably reproduced by apomixis.

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Comparison of cell wall composition between C_4 (tropical) and C_3 (temperate) grasses attracts an interest by both animal nutritionists and plant taxonomists. OJIMA and ISAWA concluded that the hemicellulose of tropical grasses was characterized by higher content of glucose and lower content of xylose than those of temperate grasses, based on the result of paper chromatographic analysis. In recent years, hemicellulose chemistry has made a remarkable progress. Much of the progress can be attributed to more accurate methods of determining the component sugars. Especially, derivatization of sugars to their corresponding alditol acetates has made it possible to analyze carbohydrates quantitatively using gas chromatography. We also attempted to use this method to determine monosaccharide composition of hemicellulose in some tropical and temperate grasses.

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