Community structure of a semi-natural grassland and an abandoned, forested grassland in central Japan (36°55'N, 139°58'E) was compared in terms of dominant species, species diversity, biomass and spatial heterogeneity of vegetation. The two study sites had been maintained as a Miscanthus sinensis grassland by regular cuttings until early 1970's. Then, the area of one site has been continuously maintained as a semi-natural grassland for approximately 30 years, using fire, cutting and grazing. The area of the other site has been experimentally abandoned, resulting in a gradual succession to a Pinus densiflora forest until the study time. (1) The semi-natural grassland was dominated by plants that are strongly resistant to treading and defoliation, such as Zoysia japonica, Liriope minor and Andropogon virginicus, while the P. densiflora forest floor was dominated by shade-tolerant plants such as Lonicera japonica, Carex lanceolata and Oplismenus undulatifolius. (2) On the P. densiflora forest floor, the species richness and species diversity were lower in small sampling areas, but higher in large sampling areas than the semi-natural grassland. (3) The biomass per quadrat in the semi-natural grassland was markedly higher than that on the P. densiflora forest floor. Spatial heterogeneity of biomass in the P. densiflora forest floor was high. (4) The P. densiflora forest floor showed a more heterogeneous spatial pattern in biomass than the semi-natural grassland, which may be caused by the patchiness of light intensity in the understory. Species with large biomass in the semi-natural grassland or the P. densiflora forest floor showed low spatial heterogeneity.

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Weeding measures are an important issue for forage sorghum because it is inferior to corn in early growth and there are not many different kinds of herbicides applicable to sorghum. Since the concern about organic animal products and environmental problem is increasing, cultivation without herbicide application is needed. Therefore, research was conducted on seeding rate for cultural weed control in the broadcasting and dense sowing of forage sorghum. Test samples were "Hazuki" for sorghum and "HSK-1" for sudangrass. Seeding rate was 2kg, 5kg, and 8kg per 10a for sorghum and 4kg per 10a for sudangrass. Hazuki grew shorter in plant length, smaller in culm diameter, and more in the number of tillers in both weeded and non-weeded plots as seeding rate increased. The amount of weed at the harvest time in without herbicide application was large when the number of sorghum tillers was few but decreased with increase in the number of tillers. Dry matter yield gradually increased as the number of tillers increased. The optimum number of tillers (the number of individual plants) was determined to be about 200m^<-2> from the amount of weed and the dry matter yield of sorghum. From the above, forage sorghum cultivation without herbicide application was judged possible by securing the number of tillers at the seeding rate of 8kg 10a^<-1> in broadcasting regardless of sowing time.

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Under rotational grazing by dairy cows, effect of stocking rate on soil animal, soil microorganism, inorganic nitrogen contents in soil, herbage production and nitrogen intake were evaluated using five perennial ryegrassdominant pastures. Each pasture was grazed at once every fifteen days from early July to early October. The stocking rate of each pasture was 10, 20, 30, 40 and 50cow-hr/ha/day, respectively. In stocking rate 10-40 cow-hr/ha/day, the number of soil animals and herbage regrowth tended to increase with increasing the stocking rate, and consequently, herbage production and nitrogen intake increased, although soil microorganisms and inorganic nitrogen contents in soil had little differences. However, in stocking rate 50cow-hr/ha/day, herbage production and nitrogen intake were lower than in stocking rate 40cow-hr/ha/day, because herbage regrowth was lower than stocking rate 40 cow-hr/ha/day, and the number of soil animals and inorganic nitrogen contents in soil were the lowest in all stocking rate-treatment.

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This study was conducted to compare the plant number and their species geminating from dung of sheep or goats. These animals were grazed on a pasture with mixed, and on another pasture only sheep were grazed. Both pastures were considerably invaded by various wild plants. The dung and the upper layer soils collected from the mixed grazing pasture were incubated in a growth cabinet for 30 days. Obvious differences were observed in the number of germinations and their species between animals or pastures and among seasons. The number of germination from sheep dung on mixed grazing pasture was more than that from goat dung during three grazing seasons. The maximum germination from sheep dung was observed in mid-July, whereas that from goat dung was in early-October. The main plant species geminating from sheep dung were Poa pratensis L. in mid-July, and those were Fesuca ovina L., Agrostis alba L. and Trifolium repence L. in early-October. On the other hand, those from goat dung were Poa pratensis L. and Anthoxanthum odratum L. in mid-July, and those were mainly forbs (dicotyledones) such as Elsholtzia ciliata (Thunb.) Hylander in early-October. Those results reveal that the number and plants species germinating from dung may be affected by vegetation of pasture, grazing season and particularly herbage selection of grazing animal.

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When hay is contaminated by many seeds of Echinochloa crus-galli (L.) Beauv. and Digitaria adscendens (H.B.K.) Henr., it is possible that these seeds disseminate over cultivation fields through the feces of cattle eating this hay. The purpose of this study is to estimate the number of seeds of both weeds in hay (Exp. 1), and to clarify which digestive organ affects the germination of the awakened and dormant seeds in vitro and in vivo (Exp. 2). The number of seeds of both weeds in hay increased as the coverage of both weeds increased. It was estimated that 10,000 seeds of both weeds were included in 1 kg of the hay from a meadow dominated by both weeds. Artificial rumen fluid alone did not affect the germination of both weeds, while acid-pepsin fluid depressed the germination largely. Awakened seeds of both weeds collected from cattle's feces showed slight germination. However, dormant seeds of D. adscendens germinated more than 20%, and those of E. crus-galli germinated to the same percentage as before being fed to the cattle. From the above-mentioned results, it appears that a large number of germinable seeds were excreted into cattle's feces, especially in the case of dormant seeds.

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Near infrared reflectance spectroscopy (NIRS) was used to predict chemical composition of forage paddy rice samples (n=191). A hundred and sixteen samples were selected for calibration development, and remaining samples were used for equation validation. NIRS accurately predicted the crude protein (CP), dry matter (DM), Organic matter (OM), organic cellular contents (OCC), organic cell wall (OCW), and low digestible fiber (Ob) content of these samples, but prediction of high digestible fiber (Oa) was markedly less accurate. The coefficients of determination and standard errors of calibration for CP, DM, OM, OCW, OCC and Ob were as follows : 0.98 and 0.33, 0.98 and 0.27, 0.95 and 0.54, 0.93 and 2.47, 0.94 and 2.64, 0.94 and 2.08. The present result in this study indicated that CP, DM, OM, OCW and Ob contents in forage paddy rice can be predicted by using NIRS techniques with an acceptable accuracy.

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We compared strength of unhulled grain for ten kinds of rice silage by using a milling machine. In these milling tests, the grain was used after drying at 55℃ for 48h. Hulling ratio and ratio of unmilled grain (milling ratio) were examined as indices of strength for the husk and for the inner part of the grain (brown rice), respectively. After storage, strength of the husk and the brown rice tended to decrease. Addition of water in ensiling process lowered strength of these parts after storage. Strength of the husk and the brown rice after storage were also different from cultivar to cultivar. In case of ensiling rice at a later ripening stage, milling ratio remained higher than in case of ensiling at an earlier ripening stage, which suggests that such high strength of the brown rice at the later ripening stage should lower digestibility of the grain.

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Effects of variety, harvest stage, chopping length were-examined for the fermentation quality of whole crop rice silage. Three varieties of forage paddy rice, 'Akichikara', 'Hosoomote' and 'Inahikari' were grown and harvested in the crop field of the Nagano Agricultural Experimental station. The crops were harvested at dough-ripe and yellow-ripe stages and ensiled into 75L container silos, with three different chopping lengths; 10, 15, and 150mm. The ensiling density of DM of whole crop rice was increased with decreasing chopping length, while it was increased with lowered moisture contents, that was associated with harvest stage. The greater improvement of fermentation quality, such as higher concentration of lactic acid and lower concentration of butyric and acetic acids, was obtained with the finely chopped silage. The results in this study suggest that the smaller chopping length can minimize effects of variety and harvest time on the silage fermentation of whole rice crop silage.

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We conducted the examination of the difference of the length of each root system from the lateral root development by using nitrate nitrogen and ammonium nitrogen to alfalfa seedling grown by water culture. The results showed that the dry weight, total root length, lateral root count, and length per one of lateral root of the seedlings in the NH_4 treated plot were greater than those in the NO_3 treated plot. The difference in total root length between the two plots was attributable to differences in lateral root number and length per one of lateral root. However, there was no marked difference in the dry weight of individual lateral roots between the NH_4 and NO_3 treated plots.

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