A glasshouse experiment was conducted at Campo Grande, the Mato Grosso do Sul State, Brazil to compare growth response of Brachiaria decumbens (following BD) and B. brizantha (following BB) to different quantities of phosphorus (following P) supply. Seedlings of the two species were transplanted in pots filled with an Oxisol applied with 0, 25, 50 and 200 kg/ha of P. The plants were harvested after 33, 62, 103 and 132 days of growth. Then dry weight of stem, leaf and root, leaf area, P contents of shoot and root, and P content of residual pot soil were measured. Crop growth rate (CGR), net assimilation rate (NAR), efficiency of applied P, acquisition rate of applied P, P use efficiency (g of forage production per g of P uptake), and P acquisition efficiency (g of P uptake per g of root weight) were calculated. P supply increased dry weight and CGR mainly through enlargement of leaf area. The effect of P supply on NAR was less than that on leaf area. NAR of BB was higher than that of BD at all P rates in early growth period. However, BB decreased its CGR and NAR rapidly at the later growth period. Therefore, it was suggested that the forage of BB should be utilized at the earlier stage than BD to avoid forage losses. Moreover, the drop of CGR and NAR of BB also suggests the necessity of a maintenance fertilizer other than P for this species. BB also showed higher efficiency of applied P and P use efficiency at a low P supply, which might have relevance to the high responsiveness of BB to fertilizer application. On the other hand, BD showed higher acquisition rate and higher P acquisition efficiency per unit root weight than BB at all rates of P supply, and it seems that those characteristics permit BD to adapt to low fertile soils. The relationship between P acquisition efficiency and root morphology of both species is also discussed.

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The purpose of this study is to compare the root biomass among five tropical grasses, which affects the level of organic matter supply into soil and mineral nutrients acquisition. Experimental pastures of Brachiaria decumbens cv. Basilisk (BD), B. brizantha cv. Marandu (BB), Panicurn maximum CV. Tanzania (TA), P. maximum cv. Tobiata (TO) and Andropogon gayanus cv. Baeti (AN) were established with two different levels of phosphorus and potassium. These pastures were grazed for three years, and then root biomass was measured in 0-10, 10-20 and 20-40 cm of soil layers. Measured root biomass represented 53-76% of total biomass of the five grasses. Among the five grasses, root biomass level per square meter was in the order of BB>BD>TA>TO>AN, with the root biomass of BB significantly higher than those of the other grasses. Root biomass in the high fertilized soil was greater than those with low fertilizer levels. Root biomass decreased quickly with the increase of soil depth, whereas the percentage of root biomass to dry soil of BB was highest among the five grasses in all of the soil layers. It is concluded that BB is the best option to be introduced in crop-pasture rotation for soil quality improvement, in terms of quantity and distribution of root biomass. The relationship between root biomass and growth response of the examined species to soil fertility is also discussed.

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Amount of intake, digestibility and nutritive value of sasa (Sasa nipponica) foliage in Hokkaido native horses were determined on woodland by the double-indicator method and compared among seasons, i.e. summer, non-snowy periods in winter and snowy periods in winter. The total number of mares and fillies used for experiment were 9 and 3 in summer, 4 and 9 during non-snowy periods in winter and 4 and 6 during snowy periods in winter. The dry matter intake of Sasa nipponica foliage was significantly higher in summer and during non-snowy periods in winter than that during snowy periods in winter (P<0.05). The apparent digestibility of NDF in winter was lower than that in summer (P<0.05). The contents of DCP and DE were 9.2% DM and 1.73Mcal/kg DM in winter, and were similar to those in summer. The DCP intake of mares and fillies were more than the maintenance requirements (NRC, 1989) of the horses in all seasons. The DE intake of mares was found to be less than the maintenance requirement of the horses during snowy periods in winter, resulting into their body weight losses during this experimental periods. The DE intake of fillies were more than maintenance requirement in all seasons, while their body weight increased in summer and during non-snowy periods in winter, and maintained during snowy periods in winter.

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The effects of three cellulase preparations as silage additives on the degradation of cell walls and sugar production for different materials were investigated. The degradation rates of cell walls were considerably different among materials or cellulase preparations. The degradation rates of cell walls were in the order of bahia grass (Paspalum noraturn Fluegge), Italian ryegrass (Lolium multiflorum L.)>naked barley straw (Hordeum vulgare L. emand Lam.)>rice straw (Oryza sativa L.) for Acremonium cellulase (AC), Italian ryegrass > bahia grass > naked barley straw > rice straw for Meicelase (MC), and Italian ryegrass > naked barley straw > bahia grass > rice straw for Onozuka cellulase (OC). Most of sugars released by cellulase preparations was glucose and there were also small amounts of xylose, arabinose and galactose, which varied with the sources of the materials or types of cellulase preparations. On the whole, the degrading capacity of cellulase preparations to cell walls was AC>MC>OC, suggesting that AC would be a more efficient additive to silage.

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Nitrogen absorption and nitrate-N content in napiergrass were investigated together with their variations among tillers by applying chemical fertilizer under more frequent and heavier amount of applications than the ordinarily normal applications. Plants were grown by transplanting the overwintered rooted tillers under the density of four plants/m^2 in early May. The fertilizer application was the combination of two levels of amount (900kgN/ha/year, H-plot and 600kgN/ha/year, M-plot) and three regimes of interval (every 4 weeks, 2 weeks and 1 week). The variations in dry matter weight, total nitrogen (TN) content and nitrate-N concentration among tillers tended to decrease with time. In the whole plant, TN concentration, TN yield and nitrate-N concentration were higher in H-plot than in M-plot in the most cases, if compared at the same application interval, and they tended to be higher with shortening the application interval before late August. It was also suggested as the prompt application method for suppressing the deterioration in forage quality that the amount of fertilizer applied in chemicals should be increased after late August, due to the lesser increase in the nitrate-N concentration compared with the case applied before August. These findings for the chemical fertilizer application were discussed with the case of cattle manure application for the slow-released effect.

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For the purpose of clarifying the desirable plant characteristics under heavy fertilization, dry matter productivities of napiergrass (Pennisetum purpureum Schumach) at the first year were compared between two varieties (cv. Wruk Wona and CV. Merkeron) under three levels of chemical fertilizer input at the rates of 1200, 600 and 120kgN/ha during the growing season from middle May to middle November. The dry matter weight of whole plant (TDMW) in Wruk Wona steadily increased with the increase in fertilizer input, while that in Merkeron showed a saturated response to fertilizer input from the medium to the highest level. These variations of TDMW were similar to the variation of leaf area index (LAI), and the latter was due to the variations in the producing rate of new leaves. The increase of fertilizer input under the medium to the highest level did not cause the increase of total expanded leaf numbers per shoot in Merkeron, but did in Wruk Wona. Thus, the increase of leaf number in response to the increase of fertilizer input level and the decrease of light extinction coefficient concurring with the increase of LAI were inferred to be the plant factors that brought about the productivity increase under high input level of fertilizer such as Wruk Wona.

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Forage maize and two-rowed barley were cultivated by a rotation system continued for 9 successive years in the four plots to which barnyard manure (BM), chemical fertilizer of N, P_2O_5 and K2_O (CF), both BM and CF (BMCF) or neither BM nor CF (NO) was applied. The yearly changes in the yields of both crops were analyzed based on the moving average and yearly deviation from the average. Dry matter yield and harvest index of forage maize were stable and high in BM and BMCF, but those in CF and NO gradually decreased year by year. The yearly dry matter yield of two-rowed barley was stable and high in BMCF, while dry matter yield and harvest index (ratio of economic yield to biological yield) in CF decreased yearly and varied widely with the year. Disease was frequently observed in both crops from the 3rd year in CF but not in BM and BMCF. Total nitrogen and carbon in soil were clearly high at the 2nd and 5th year, respectively, than other years in BM and BMCF, but were constant in NO and CF. The value of K/(Ca+Mg) highly correlated with the occurrence of grass tetany was as high as 3-4 in forage maize at the 6th year in CF and BMCF. Crop rotation of forage maize and two-rowed barley in the field only with chemical fertilizer application became difficult within 3 years, and the improvement of mineral balance and soil physical property by applying barnyard manure or inorganic soil amendments became necessary. Chemical fertilizer (N, P, K) application together with barnyard manure application of 11 kgm^<-2>y^<-1> affected mineral composition of feedstuff.

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The maintenance of botanical composition is extremely important for management of pasture. The study of vegetation under various management conditions is very useful for understanding the relationships between species diversity and stability of community. We compared the botanical composition of pastures between two dairy farms seeded same seeds of pasture species on 12 years ago. Botanical composition and species diversity were different between two farms by different grazing managements. The pasture of A farm was dominated by short grass such as Poa pratensis through continuous high stocking rate. The botanical composition of pasture of B farm changed little for 12 years by delicate grazing arrangement. The species diversity of pasture of B farm was significantly higher than these of A farm. These differences between two farms might be reflected by the differences of farm management.

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Twelve multiparous Holstein cows (average weight, 640 kg; average milk yield, 9,574kg) in early lactation were investigated in the switch-back experiment with three periods to evaluate effects of feeding level of corn silage on DM intake, milk production, and feeding cost. Cows were fed either 1 kg of timothy hay and corn silage ad libitum (CS) or 5 kg of corn silage (dry matter basis) and timothy-red clover silage ad libitum (CG), with supplemental concentrate to meet the nutrient requirements of NRC. Concentrates and forages were offered separately. Corn silage contained 7.3% of CP and 66.5% of TDN, and timothy-red clover silage contained 12.1% of CP and 63.9% of TDN. DM intake and the ratio of forages to concentrates of CS treatment were similar to CG treatment. There were no effects of feeding level of corn silage on milk yield and composition. Feeding costs of forages for CS treatment (390 yen/day) as calculated according to the assessment of the local production cost (corn silage=27.6yen/kgDM, timothy-red clover silage-22.6 yen/kgDM, timothy hay=33.4 yen/ kgDM) was higher than for the CG treatment (348 yen/day). Total cost of feeding in the CS (27yen/4% FCMkg) was higher than the CG (24 yen/4%FCMkg), whereas the the CS treatment was estimated to more income (milk production per ha) 1.34 times higher than the CG treatment. These results suggested that corn silage is profitable for high producing cows to increase benefit because of higher crop yield per ha.

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Forty-seven commercial varieties of sorghum (Sorghum bicolor Moench) and 8 commercial varieties of sudangrass (Sorghum sudanense (Piper) Stapf) were investigated to determine variability in feed composition and growth characteristics, as conventionally grouped in Japan to the five types of varieties including grain- (G), dual purpose(D), sorgo- (S), sorghum-sudangrass hybrid-type (SS) and sudangrass (SG). As 7 variables of crude protein (CP), organic cellular contents (OCC), neutral detergent fiber (NDF), acid detergent lignin (ADL), nitrogen cell wall free extracts (NCWFE), in vitro dry matter degradability (DMD) and in vitro cell wall degradability (CWD), were analyzed by the principal component analysis, the 1st and 2nd principal component were proportion of cellular contents to fiber elements and constituents of cellular contents, respectively. The cumulative proportion of these two principal components accounted for 82% of the variation. Four types of the G, D, SS and SG in sorghum and sudangrass were shown individually to have the high similarity of feed composition, while that of the S type widely varied. As the S type of sorghum was semi-divided into 3 groups including molasses- (M), normal- (N) and extremely late maturing-type (L), their characterization of both feed composition and growth was much more certain. The DMD of sorghum varieties was significantly inversely related to NDF content and acid detergent fiber (ADF) content(r= -0.98, P< 0.001, both), the nutritive value suggesting the order of G ≒ D >M>N>SS>L. The higher CWD of the SG compared with those of sorghum varieties, although the SG had higher NDF content than the sorghum, might also indicate the heterogeneity of the SG from the other sorghum varieties examined. It was concluded in the present study that the classification of varieties of sorghum and sudangrass into 7 types was informative for their cultivation and utilization in the farm.

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Changes in the dry matter yield and rumen digestibility of forage sorghum by bird injury were investigated on two types of sorghum incruding the grain type of variety, GS 401 (commercial release), and the dual-purpose type of two inbred lines (3 : 42-3-1 and 3 : 45-1-1) developed at Nagano Animal Industrey Experiment Station, Japan. Forage sorghums tested, characterrized of early maturation and high susceptibility to bird attack, were grown in experimental crop field with (covered plot) or without bird protection net (uncovered plot) and sampled to determine the effects of bird injury on the dry matter yield and rumen digestibility at dough stage. Grains of the three sorghums in the uncovered plot were not almost yielded, whereas dry matter yield and watersoluble content of follage in those sorghums were much higher than those of the covered plot. Consequently, loss of whole dry matter yield of the sorghums in the uncovered plot was compensated by increase of foliage parts, the values showing around 78.2 to 91.6% against each of the sorghum cultivars in the covered plot. Dry matter disapperance in the rumen of foliage in the uncovered plot was also increased by the average value of 12.2% unit as compared to those of the sorghums grown in the covered plot. However, the yield of the indigestible matter and digestible structural matter in foliage were similar in the covered and uncovered plot. It would be assosiated with grater translocation of photosynthate in leaves and culms after bird picking of young grains, because the increase in the yield and digestibility of the foliage in the uncovered plot was mainly caused by the excess storage of watersoluble matter. It was thus suggested in this study that grain type and dual-purpose type of sorghums injured by bird attack even can yield the digestible matter similar to sorgo type of sorghums.

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A Windows 95 program was written to support decision making in the planning of recreational facilities in pastureland. It has enhanced subroutines, accuracy, and image quality that were gained by adding functions to evaluate landscape diversity using data for a 50 × 50 m grid and landscape simulation software. A digital elevation model and land use map covering a 2049 × 2049 grid square, where each grid represents 15 × 15 m, was designed for this system so that it can evaluate a 31 × 31 km area. This system provides an overview of a large area and can extract closer views of areas of grassland at short or middle distances. The evaluation map not only indicates areas of grassland, but also calculates landscape diversity from changes in land use and visibility. When one point on the distribution map is selected that contains grassland, the land use and geographical diversity in the landscape, the visible grassland area from this point are displayed in separate windows. The use of windows for different functions enables any process to be performed at anytime; so that the validity of proposed plans can be examined and confirmed easily. Moreover, since the operating system and reference frame for this system use the same software as a landscape simulation program, which allows short 'walks' through an animated image, both programs can be used at the same time. This system makes it easier to evaluate a landscape beforehand, while planning recreational facilities and roads in pastureland.

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To evaluate the landscape of semi-natural grassland in the area of Mt. Sanbe economically, we applied dichotomous choice contingent valuation method (CVM). Some questionnaires were conducted to the tourists visiting Mt. Sanbe, in Shimane Prefecture, western Japan, where designated as national park in 1963 because of the beautifulness of grassland landscape. Main questionnaire was about the willingness of tourists how much to pay (WTP) if the grassland had been missing and a kind of funds to conserve the grassland would be established. The median and the mean of individual WTP worked out from the result of the questionnaires were 3,674 yen and 6,497 yen, respectively. By multiplying these values to the official number of annual visitors to Mt. Sanbe from April to November, 627,500, the amount of the economic value of the semi-natural grassland landscape in this area per year can be calculated. The higher-priced one calculated with the mean WTP came up to be about four billion and seventy million yen, and the lower one with the median WTP was about two billion and three thousand million yen.

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