Effects of phosphogypsum (PG) applied in topsoil on amelioration of subsoil acidity of nonallophanic Andosols were studied comparing with that of calcium carbonate (lime). Both barley (Hordeum Vulgare L.) and alfalfa (Medicago sativa L.) were grown on Katwatabi (thick high humic) and Kitakami (light colored) nonallophanic Andosols treated by different amounts of PG. 1. After 1012 mm of rain, 82% of Ca applied as lime to topsoil still remained in topsoil, whereas about 75% of Ca applied as PG moved toward subsoil reflecting their relatively high solubility. 2. Both pH (H_2O), intensity factor of soil acidity and exchangeable acidity y^1, capacity factor of it, were extremely lowered in Kitakami Andosol with phosphogypsum (10g/kg soil) application, but not in Kawatabi Andosol attributing to high buffering and chelating ability of humus contained. 3. Root growth of both barley and alfalfa in Kitakami Andosol were extremely amended when increasing the application rate of phosphogypsum. 4. Possibility of ameliration of subsoil acidity by PG application to topsoil were strongly suggested in nonallphanic Andosols, especially in light colored nonallphanic Andosols.

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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 dry matter intake (X_<DMI> : g/kg^<0.75>) : Y_<DDMI> = a+bX_<DMI> and the curvilinearity of the relationshipe between dry matter digestibility (Y_<DMD> : %) and 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 supreme dry matter digestibility (=b) and excretion of delayed residues flow through gastrointestinal tract (=a). The both regression equations are obteined samely in crude protein, cell contents and cell wall The fill of dry matter in the gut (DMF ; g/kg^<0.75>) would equal the dry matter intake added to (a). The rate of passage (Kp) can be represented by Kp = dry matter excretion / DMF The rate of digestion (Kd) can be represented by Kd = digestible dry matter intake / DMF Kp and Kd cell contents, cell wall and crude protein were estimated samely these of dry matter. For the first cut of orchardgrass and alfalfa in the spring, Kp of dry matter, cell contents, cell wall and crude protein increased and Kd of these composition decreased with the progression of the growth stage. For the regrowth of orchardgrass in the summer and autumn, the value of Kp and Kd changed samely for the first cut, But there were not difference in the change of regrowth among alfalfa. There was significant positive correlation between voluntary dry matter intake and Kd of dry matter among orchardgrass. But there was not significant correlation between them among alfalfa. Estimated average values of total amount of dry matter present in the gut (fill), Kp and Kd are shown below : orchardgrass : fill = 73.5g/kg^<0.75>, Kp = 0.30, Kd = 0.51 alfalfa : fill = 92.4g/kg^<0.75>, Kp = 0.32, Kd = 0.54

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The association of Z. japonica and D.glomerata is useful as a low-input and stable pasture for beef cattle grazing in the mountaneous area of Japan. The methods of establishment and management of association were studied from an ecological view point. Seeds of Z. japonica and D. glomerata were oversown without tillage after clearing of deciduous broad-leaved forest in Sep., 1980. The three different amounts of chemical fertilizers were applied to the treatment plots were grazed by beef cattle for 5 years. The effect of fertilization on changes in shoot densities and weights of Z. japonica and D. glomerata under the grazing condition were examined in this report. 1) Shoot density of D.glomerata was approximately 500 shoots/m^2 during 5 years after start of grazing in the non fertilized plot, although it was the lowest among all plots. 2) Shoot density of Z. japonica in the non fertilized plot was 284 shoots/m^2 in the first year after start of grazing. It increased year by year and surpassed that of D. glomerata after the third year. The density of Z. japonica in the low fertilized plot increased slightly year by year (12-64 shoots/m^2), but was relatively low level until the last year. However, seedlings of Z. japonica disappeared in the second year in the high fertilized plot. 3) Standing crop in the non fertilized plot was very few (38.7g DM/m^2) in the first year. However, it increased at 110.2g DM/m^2 in the second year due to active regrowth of D. glomerata. From the fourth year regrowth of D. glomerata reduced, and Z. japonica expanded as an alternative. Therefore, standing crop in the non fertilized plot increased continuously as a whole and reached at 273.3g DM/m^2 in the fifth year, the amount of which was similar to that in the low fertilized plot. 4) The amount of available forage for grazing cattle in the non fertilized plot was estimated to be a quarter of in the high fertilized plot, although there was an exception of low amount in the first year. 5) Vertical distribution of underground parts in the non fertilized plot indicated that D. glomerata which dominated in the first year would be gradeually replaced by Z.japonica. 6) From these results no fertilization was indispensable for the establishing Z. japonica-D. glomerata association after clearing of deciduous broad-leaved forest. However, once the stand was established, small amount of fertilization (about 20-30 kgN/ha/year) should be applied to keep vegetational equilibrium between both species.

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Microflora, specifically lactic acid bacteria (LAB) on different species, organs and regrowth stages of forage crops and grasses (FG) were investigated in 350 samples obtained from 33 species and varieties. The regional difference in the microflora of FG were also studied between Ehime and Tochigi prefectures. One hundred and thirty seven strains of LAB were isolated from FG, lacto-cocci and lactobacilli were classified by their morphological characters, the fermentation type and optical form of lactic acid were also examined. The results are summarized as follows : 1) Aerobic bacteria, mold and yeast, lacto-cocci and lactobacilli were higher in the decreasing oreder of corn, sorghum, legumes, soiling crops, tropical grasses, temperate grasses and other crops. Aerobic bacteria, mold and yeast gave higher plate counts than LAB in all the samples collected. 2) Higher numbers of microorganisms were abtained from FG which were growing at Ehime Prefecture than those from Tochigi Prefecture. 3) On the organs of FG, the numbers of microorganisms were higher on flowers and spiklet than on stem and leaf. 4) At the stage of regrowth, the numbers of microorganisms were : vegetative<internode<elongation<heading<flowering<milk ripe<full ripe. During regrowth of FG, LAB, specifically lactobacilli was consistently present in lower levels than aerobic bacteria, mold and yeast. 5) The ratio of lactobacilli and lacto-cocci to total LAB isolated was from 20 to 30% and from 70 to 80%, respectively. The homefoermentative LAB occupied from 53 to 83% of total LAB. 6) With regards to the optical isomers of lactic acid produced, the ratio of LAB producing DL racemic mixture was 62-80%, and the ratio of LAB producing exclusively the L (+) and D (-) isomers were 8-20% and 6-24%, respectively. The above results clearly shows that the microflora on FG vary with different FG species, organs, stages of regrowth and region, and the LAB produced exclusively L (+) lactic acid indicating relatively a low productive ratio of lactic isomer.

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It is desirable for timothy (TY) meadows in Konsen district, Hokkaido, to produce forages with more than 65% in total digestible nutrients (TDN). This research was to investigate the effects of cutting time, -interval and -frequency on dry matter yield, TDN and weed invasion. Pure sward of TY variety "Nossapu (early muturing)" was established in 1985. Seven cutting treatments were conducted by combining the times of 1st and 2nd cutting and the annual cutting frequency. Experiment was continued for 3 years from 1987 to 1989. Results were summarized as follows: a. All treatments were under the dominance of TY in 1987 and 1988. However, white clover and rhizomatous type grasses (RG) invaded all treatments in 1989. Composition ratios of both species increased in accordance with the progress of harvest. Especially, the ratio of RG was higher in the early harvest (EH) than the other treatments. 2.In the number of tillers of TY, seasonal change did not show a constant tendency and the difference was not observed among the years or treatments. 3. Annual dry matter yields were less in EH treatments than in control treatment (twice cuts a year, sith the 1st growth and the regrowth at the heading time). This could attribute to smaller weight per tiller in EH treatments. 4. TDN contents were higher in EH treatments (62-69%) than in control treatment (62-63%). Especially, TDN contents of all harvest were highed (66-69%) in the 3 times cut treatments, with the 1st growth at booting-initial heading time, the 2nd cutting in about 40days after 1st cutting and the regrowth. However, TDN yields in those of the treatment were less than control treatment. 5.From the above results, the adequate cutting management to obtain forages with more than 65% in TDN was the 3 times cut with the 1st cutting at booting-initial heading time, the 2nd cutting in about 40 days after 1st cutting and the 3rd cutting at the beginning of October. Also, it was pointed out that attention should be paied to the change of botanical composition, especially invasion of weed including RG.

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Three rumen cannulated goats were used to investigate the effect of NaOH and NH_3 treatment (2.74% DM) at ensiling on digestion, nitrogen utilization and in situ protein degradation of low moisture alfalfa silage. Wilted alfalfa was sprayed with water (control), NaOH or NH_3 solution, and fed to goats after 6 months storage in 3×3 Latin square design. Both alkali treatments increased the pH value, NH_3-N and butyric acid of the silage, but NH_3-treated silage preserved as much amino acids as control silage. The two alkali treatments could not improve digestibilities of fibrous components (NDF, ADF and cellulose), and NaOH addition significantly reduced the digestibility of crude protein. The NaOH treatment decreased the rate of N degradation in the rumen, while solubility and potential degradability was not affected by the treatment. The NH_3 addition increased ruminal soluble nitrogen in the silage, but rate of N degradation was similar to that of control silage. These results suggest that NaOH treatment would make protein less susceptible to microbial degradation in the rumen despite of deteriorating the fermentation quality of the silage.

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This Study investigated sod-pulling by beef cattle grazing two paddocks of a bahiagrass pasture on sandy soil. The sod-pulling was often observed during the grazing season. The number of sod materials pulled per day was in the ranges of 0.54-9.23 materials/m^2 and 181-1961 materials/head. Bahiagrass accounted for 13.3-96.8% of the number. The weight per sod-pulled material was in the ranges of 159-493 mg DM in bahiagrass and 53-248 mg DM in other species. The aboveground parts accounted for 52.9-68.1% and 64.6-91.7% of the weight per material in bahiagrass and other species, respectively. There were positive linear relationships between the weights of plant parts in bahiagrass. The weight of sod materials pulled per day was in the ranges of 0.06-1.40g EM/m^2 and 22-298g DM/head for the aboveground parts, 0.02-0.88g DM/m^2 and 4-188g DM/head for the total plant parts. Bahiagrass accounted for 11.9-99.2%, 33.3-99.4% and 15.3-99.2% of the weights of aboveground parts, belowground parts and total plant parts, respectively. In bahiagrass, the aboveground weight pulled per m^2 per day was positively and linearly related to the herbage mass above the ground level. The slope of the line was greater in the smaller paddock. Based on data obtained, the factors affecting the sod-pulling were discussed, and the plant losses due to the pulling were estimated.

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There are few reports available on the dynamics of pasture plant roots, because such root investigations are very time-consuming and require considerable labor. Therefore, the authors devised a method using a fiberscope by which elongation and turnover of pasture plant roots could be recorded photographically. We applied this method to a grazing pasture and collected information from which we could estimate elongation rates, death rates and turnover rates of roots. The glass tube (8cmφ×50cm) was buried in the soil in November 1984. At one or two week intervals from February 1985 to January 1988, we inserted a fiberscope (OLYMPUS IF-11D3-10) into the glass tube and took nine pictures at different depths (2.5cm-22.5cm). The root lengths in each picture were measured with a curvimeter. The results were as follows: (1) The total lengths of all roots at one view, called "present root length", increased rapidly from end of March through May 1985 at each depth. After this rapid increase, the increment of "present root length" was small and kept, more or less, constant. As "present root length" was apparently constant, it was assumed that the newly appearing roots took the place of dead roots. Therefore, the length of newly appearing roots at each observation were measured and summed. This summed root length is called accumulated length of newly appearing roots. The difference between the accumulated length of newly appearing roots and the "present root length" indicated the accumulated length of dead roots. (2) Root elongation rates, estimated from the accumulated length of newly appearing roots, at the nine different depths, tended to be high during April to May and November to December each year. But seasonal changes in root death rates, estimated from the accumulated length of dead roots, were unclear. (3) Average turnover rates of roots at the nine different depths, estimated from the mean "present root length", annual length of newly appearing roots and dead roots, was calculated as 1.05/year in 1986, 0.88/year in 1987.

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This paper, using the previously-shown energy and nitrogen flows in the dung-free, dung-deposited and dung-surrounding places in a bahiagrass pasture grazed by dairy heifers, examined the relationships between the energy and nitrogen flows. The energy flows investigated were net primary production (P_E), energy grazed by the animals (G_E), energy transferred to the litter (L_E) and energy stored in the plants (S_E). The nitrogen flows investigated were nitrogen uptake (U_N), nitrogen grazed by the animals (G_N), nitrogen transferred to the litter (L_N) and nitrogen stored in the plants (S_N). There were significant positive linear relationships between P_E and U_N, G_E and G_N,L_E and L_N, and S_E and S_N, shen all the data were pooled. These overall relationships, owing to the meanings of the parameters of the regression equations, were considered to give us the information which is useful for predicting the energy and nitrogen flows in the system and for characterizing the system. The P_E/U_N relationship was influenced by the dung resulting in an acceleration of U_N, though the degree of influence varied with the time after the dung deposition, the distance from the dung and the time of the dung deposition. In contrast, the G_E/G_N relationship was hardly affected by the dung. These facts indicated little contribution of the dung-induced stimulation in the U_N to the nitrogen content of grazed herbage. The results emphasized a need to investigate the dung-affected nitrogen uptake in the whole plant parts and in relation to the soil chemical status.

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Tall fescue (Festuca arundinacea Schreb.) plant has been often reported to reproduce by its rhizomes, although it has been generally considered as a bunch-type grass. We studied the clone structure of an 8-yr-old pasture population of F. arundinacea cv. Hokuryo using starch gel and polyacrylamide electrophoresis to examine the extent and patterns of clonal spread. Preliminary experiment on intra-cultivar variation in zymograms of five enzyme systems (ACP, EST, GOT, 6PGD and PGI) confirmed the usefulness of these methods for clone identification in combination with mapping of the relative positions ramets within the sward. Two 1×1m^2 quadrats were sampled from the sward and determined for the phenotypes of all stands by five enzyme systems. Of 54 genets identified over two quadrats, fourteen ones contained two or more ramets that were distributed closely each other. This result suggested that this F. arundinacea population may be maintained partly by rhizomes. This electrophoretic method distinguishing the clones will be useful in detecting more persistence genotypes of F. arundinacea in grazed swards.

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We examined tue usefulness of isozumes for the clone identification of Trifolium repens to enable to determine the extent and pattern of its clonal spread in fields. Twenty-one enzyme systems were examined using starch gel electrophoresis for the nine buffer systems (ranging from pH 5.5-8.6) to select appropriate ones. Of these enzymes, three ones (aconitase (ACO), esterase (EST), and phosphoglucoisomerase (PGI)) showed high resolution and were highly polymorphic. The examination of the extent of intra-cultivar (cv. Grasslands Huia) variation in these enzymes strongly indicated the usefulness of the isoaymes for the clone identification. Using this method, we analysed the clone structure of a T. repens mini-sward population, distinguishing well genets intermingled each other. A practical procedure for the clone identification in fields will be also proposed.

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