Green panic seeds treated with soaking in running water and storing at temperature of 35℃ and differed in harvest date and volume weight were examined their emerging ability in soils with constant soil moisture 70, 55, 40% and varied soil moisture 35 (initial)-60 (later)%, respectively. Tests were made 5 times in 5 years after seed harvest. Results obtained were as follows ; 1. Emergence percentage was generally low in seeds 7 months after harvest, and increased a year after harvest in soils with 70% (pF2.5) and 55% (pF3.7) moisture. Emergence percentage in soil with 40% (pF4.2) moisture was lower than that in soils with higher moisture, but it increased gradually in the course of years. Exposure to low soil moisture (pF4.3) for 7 days from sowing markedly decreased emergence percentage untill a year after harvest, and this adverse effect continued for years. 2. Seeds stored at temperature of 35℃ showed remarkably higher emergence percentage and faster emergence than the seeds stored at room temperature, and this effect was considerable in soils with low moisture. Seed treatment, soaking seeds of 1.5 months after harvest in running water for 96 hours and then drying, fastened emergence and, in some cases, increased emergence percentage in soils with high moisture. 3. Emergence percentage of heavy seeds (volume weights were about 340mg/cc) was higher than that of light seeds (volume weights were about 270mg/cc), and the light seeds were affected more severely by low soil moisture (40% or inital 35%) than the heavy seeds. 4. Emergence percentage was lower at high temperature (25℃) than at low temperature (20℃) in soils with low moisture, while in soils with high moisture emergence percentages at both temperatures were equal. 5. In general, seed harvested in mid-September emerged better than seed harvested in late August.

View full abstract

Green panic seeds treated with soaking in running water and storing at temperature of 35℃ and differed in harvest date and volume weight were examined their germinating ability on filter paper moistened with water, KCl 0.03M and KCl 0.06M solutions. Tests were made 5 times in 3 years after seed harvest. Results obtained were as follows ; 1. At 8 months after harvest, seed stored at temperature of 35℃ since 1.5 months after harvest had already obtained the highest germination percentage in each solution. However, germination percentage of the seeds stored at room temperature was low even in water and poor in KCl solutions at this time. Germination percentage increased for one year after harvest, and then maintained nearly similar percentage in each solution for 1.5 years, untill the end of this experiment. 2. Seed stored at temperature of 35℃ showed higher germination percentage and faster germination rate than the seeds stored at room temperature, and the improvement of germination in KCl 0.06M solution was considerable. 3. Seed treatment, soaking seeds of 1.5 months after harvest in running water for 96 hours and then drying, gradually improved germination percentage in water for 2 years after the treatment. Thereafter, germination percentage of this treated seed was higher than that of not treated one. 4. Seed treatment, soaking seed of 1.5 months after harvest in running water for 3 hours and then drying, increased germination percentage in some degree at 7 months after the treatment, but afterwards it had no longer positive effect for germination. 5. Generally, heavy seeds (volume weights were about 340mg/cc) showed higher germination percentage than light seeds (volume weights were about 270mg/cc). 6. Germination behavior of seed harvested in mid-September was somewhat similar to that of the soaked seeds harvested in late August.

View full abstract

Studies were carried out with one-year-old orchard grass, fertilized yearly since planting, with the following seven treatments in the field: 0.8kg N/are, 1.5kg P_2O_5/are and 0.7kg K_2O/are (control), higher N level of 2.4kg N (3N), higher P level of 4.5kg P_2O_5 (3P), higher K level of 2.1kg K_2O (3K), no added N (-N), no added P (-P) and no added K (-K). The nutrients, except for each treatment element, were added at the same level as the control. The quantitative and qualitative variations of non-structural carbohydrates (NSC) in the leaf-sheath were investigated with time course sampling from September to December, 1970. The seasonal variation of NSC differed for grasses grown in different nutritional environments. The -N treated grass accumulated NSC of higher concentration and higher degree of polymerization than all other treatments at early autumn. The concentration of NSC of 3K treatment was not as high as the -N treatment, but the degree of polymerization increased more in the 3K than in the -N treatment at an early stage. The progression of the polymerization of the NSC in -K and 3N treatments occured more slowly than in the control. The concentration of NSC of both -P and 3P treatments were higher than the control and the composition of them were made from highly polymerized NSC from an early stage. As these above results show, the application of a high rate of N fertilizer delays the accumulation of NSC and formation of highly polymerized carbohydrates (fructosan) in the leaf-sheath of orchard grass. On the other hand, the application of K fertilizer accelerates the formation of highly polymerized carbohydrates. It was assumed that K was closely linked to not only the synthesis of starch granules but also to the formation of long chain fructosans.

View full abstract

This study was conducted to clarify the interspecific difference of the relationship between nitrogen content of leaf blade and leaf photosynthesis in sveral tropical and temperate grasses, and legumes. Experimental plants were grown in pots with various levels of nitrogen fertilizer. The apparent photosynthetic rate of the youngest fully expanded leaf was measured in assimilation chamber. Leaf nitrogen was analysed by the semimicro-Kjeldahl method and percentage of contents were determined on the dry weight basis. The results are summarized as follows: 1) Tropical grasses (Echinochloa utilis, Eleusine corocana, Chloris gayana, Panicum maximum), native grasses (Eragrostis ferruginea, Pennisetum alopecuroides) and weeds (Digitaria adscendens, Echinochloa Crus galli), which are all possessing C_4 cycle showed 1.5 to 2 times higher photosynthetic rates per unit leaf nitrogen content (PN) than those of the temperate grasses (phleum pratense, Festuca arundinacea, Dactylis glomerata, Lolium multiflorum) and about 2.5 times higher than those of the legumes (Medicago sativa, Trifolium repens). Temperate grasses were about 1.3 times higher PN values than those of legumes. Leaf nitrogen concentration for the optimum PN values varied among species ; 2 to 3% for the temperate grasses and about 5% for the legumes. On the other hand, those for C4 species were about 4.5% for weeds, about 1.7% for native grasses and 2.5% to 3.5% for tropical grasses in leaf nitrogen concentration, respectively. 2) In all species, a linear relationship was observed between leaf photosynthetic rate and leaf nitrogen percentage in lower level of leaf nitrogen concentration. However, as nitrogen concentration in leaf became higher, photosynthetic rates of most species were saturated, followed by decline according with further increment of nitrogen percentage. The values of leaf nitrogen concentration which brought the maximum photosynthetic rates were different among species ; 4 to 6% for temperate grasses, about 6% for legumes and 4 to 5.5% for C4 species, respectively. 3) Inclination of light-photosynthesis curves were different among species as well as among nitrogen levels of leaf. In the case of similar levels of nitrogen percentage in leaf, light-photosynthesis curves of C4 species were much steeper than those of C3 species. In both C3 and C4 species, at high light intensities, leaves with higher nitrogen percentage exhibited higher photosynthetic rates than those with lower nitrogen percentage. There were, however, little difference at low light intensities. When the leaves contained less than about 2% leaf nitrogen, light-photosynthesis curves leveled off at relatively low light intensity.

View full abstract

A sand culture green house experiment disclosed patterns of regrowth of plant top and root, nodule development, nitrogen fixation (C_2H_2 reduction), and total non-structural carbohydrate (TNC) concentration in Macroptilium atropurpureum cv. Siratro imposed with five clipping treatments, viz., [table] Plant top DM or root DM weight was much decreased with clipping all leaves on the stubble or with lower clipping height, showing important but different roles of leaves and stem in vegetative regrowth of Siratro. Different clipping treatments imposed different degrees of influence on the rates of nitrogen fixation by this legume: Nitrogen fixation did not drop with higher clipping heights with leaves on the stubble and some drops occurred for a short period after clipping in the other treatments. The periods required for the recvery of nitrogen fixation were shorter for higher clipping height and for greater leaf areas remained on the stubble when treatments were imposed. High root TNC concentration in Siratro seems to mitigate adverse effects of clipping treatments and accelerate vegetative regrowth of this legume. With the above results, higher clipping heights with longer clipping Intervals were recomended for the practical management of Siratro.

View full abstract

This experiment was carred out in order to clarify the effects of harvesting time of second growth and pre- or post-harvest application of nitrogen on the late autumnal regrowth of orchardgrass. In a pot trial, second growth of vegetatively propagated orchardgrass were cut on Aug.10th, 20th, 30th or Sept.9th and 2.71g of ammonium sulfate (12kg/10a as N) was given to each pot ten days before or ten days after each cutting time of second growth. They were grown in the glass house (mean max. temp. 30.5℃ and mean min. temp. 12.0℃) as a high temperature condition or in the net house (mean max. temp. 20.5℃ and mean min. temp. 9.1℃) as a normal temperature condition. Samples were collected from all pots on Oct.28th and then chemical composition and in vitro digestibility were determined. The results obtained were as follows. 1. Dry matter yields decreased markedly with delaying the cutting time of second growth in the combination with post-harvest application of nitrogen. On the contrary, in the combination with pre-harvest application, higher herbage yields were obtained from the delayed cutting as on Aug.30th or Sept.9th than the earlier cutting as on Aug.20th. Therefore, on Aug.30th or Sept.9th cutting treatment, the plants of pre-harvest application of nitrogen produced higher dry matter yields than those of post-harvest application. Orchard-grass produced higher yields under the high temperature condition than the normal temperature condition. 2. Contents of DCP and TDN, and in vitro digestibilities of dry matter and cellwall constituent increased with delaying the cutting time of second growth. But, nutritive ratios were lowered with delaying the cutting time of second growth. Nutrtive values and digestibilities were slightly decreased under the high temperature condition. Contents of DCP in plants were low in the pre-harvest application of nitrogen compared with those in the post-harvest application, althogh contents of TDN and in vitro digestibilities were almost the same under both treatments. So, the nutritive ratios of the plants in pre-harvest application of nitrogen were relatively higher levels than those in post-harvest application, i.e. applying nitrogen before harvesting second growth resulted in 'low protein but high energy contents' of the late autumnal regrowth. From the above results, it can be concluded that regrowths and nutritive values in late autumn are influenced more strongly by the applying time of nitrogen than cutting time of second growth. Furthermore, it is suggested that pre-harvest application of nitrogen to second growth may be an advisable method to save orchardgrass sward from late summer for late autumnal use.

View full abstract

This paper described the productivity of forage plants in the middle-aged Japanese red pine forest. 5 experimental plots differed in tree stand were established by thinning in autumn of 1975 ; ordinarily thinned plot (1578trees/ha), 25% more heavily thinned plot (1147trees/ha) and 50% more heavily thinned plot (779trees/ha) in the pine forest of age 20-25 years, ordinarily thinned plot (525trees/ha) in the pine forest of age 40-45 years and the control plot (open area). Table 1 presented the condition of forest after thinning. The forage plant species used were orchardgrass (Dactylis glomerata), perennial ryegrass (Lolium perenne), meadow fescue (Festuca elatior), Kentucky bluegrass (poa pratensis) and white clover (Trifolium repens). A great difference in herbage yield was recognized among experimental plots. The mean yields of herbage for 4 years were 825.4, 1192.3, 1644.2 and 1499.7kg/10a in ordinarily thinned plot, 25% more heavily thinned plot, 50% more heavily thinned plot of age 20-25 years and ordinarily thinned plot of age 40-45 years respectively (Table 4). The difference in herbage yield among the plots was probably related to the relative intensity of solar radiation on forest floor resulting from the difference of tree stand structure (Table 2). Also, the herbage yields in all forest plots decreased with years after 1977. It was the reason that the relative intensity of solar radiation reduced with the growth crown coverage (Table 5). The seasonal pattern of herbage yield was different between the control plot and the forest plots definitely (Table 6). The spring flush did not appear evidently in the forest plots because of the insufficient solar radiation. The number of heading plant was correlated positively to the relative intensity of of solar radiation (r=0.94, p<0.001). The botanical composition changed considerably with the relative intensity of solar radiation on the forest floor ; for instance, orchardgrass was the dominant species in the control plot while perennial ryegrass and Kentucky bluegrass were the dominant species in the forest plots (Table 7). The tiller's number of orchardgrass was correlated positively to the relative intensity of solar radiation (r=0.90, p<0.001). Also, The grass height and tiller density in the forest plots were lower than those in the control plot.

View full abstract

Autecological studies were carried out on seed population and germination characteristics of Zoysia japonica seed in cattle dung deposited on the Zoysia type grassland. The cattle dung were collected from the grassland at Sugadaira, Nagano prefercture in early spring of the following year of dung deposition. The number of species and the total number of seed grains contained in the dung sampled were 13 species and 6648 seed grains per 100 DM. g dung. The number of seed grains of Zoysia japonica, Veronica Onoei, Carex nervata and Potentilla Freyniana were 6229, 232, 86 and 27 per 100 DM. g dung, respectively. Subsequently, some germination experiments were performed to compare germina haracteristic of Zoysia japonica seeds hand-collected to that contained in the dung. The results are as follows. 1. Neither hand-collected seeds nor seeds contained in fresh dung showed any germination in late August. 2. After chilling at 1-5℃ for 120 days, the per・cent of germiation after 10 days of the seeds in dung was 35%, while that of hand-collected seeds was only 14%. 3. In natural condition, the seeds remained in the dung seemed to have been exposed to natural chilling during winter. When the seeds taken out from the dung were exposed to chilling in the laboratory during the corresponding period, the per・cent of germination of seeds was almost similar to that of naturally chilling seeds. 4. The per・cent of germination of the hand-collected seeds buried in the dung and chilled was similar to that of the seeds supplied with water and chilled in the Pe・tri dishes. 5. The seeds from two sources were collected in early spring, one was the seeds contained in the dung and another was collected from the ear in the preceding year. Both seeds were exposed under natural chilling by passing the winter on the grassland. The per・cent of germination of the seeds in the dung was 84% at 30/10℃ (day/night temperature regime) and 34% at 20/10℃. On the other hand, that of the seeds from the ear were 34% at 30/10℃ and only 4% at 20/10℃. From these results, we can recognize that morphological structures and physiological character such as fruit ripening and seed dormancy, of Zoysia japonica seed are considered to relate with grazing of livestock. The results also suggest that we can improve undesirable vegetation to Zoysia japonica vegetation by spreading the cattle dung contained seeds.

View full abstract

In order to clear study the characteristic of seedling growth of Zoysia japonica as compared with Dactylis glomerata, the pot experiment was conducted under day/night temperature regimes of 34/29, 29/24, 24/19 and 19/14℃, respectively. 1. The rate of leaf appearance of Zoysia japonica was the highest at 34/29℃ plot and that of Dactylis glomerata was the highest at 29/24℃ plot. Comparing the growths of both grasses under these temperatures, the results obtained were shown as below. 1) The leaf appearance on main stem of Zoysia japonica was later than that of Dactylis glomerata untill the 3rd leaf of main stem appeared. After the 4th leaf appeared, the rate of leaf appearance was more rapid in tae. former. 2) The first tiller of Zoysia japonica appeared from the second leaf axil at 35 days after germination when 6 leaves expanded on main stem. On the other hand, that of Dactylis glomerata appeared from the first leaf axil at 25 days after germination when 4 leaves expanded on main stem. 3) C/F ratio of Zoysia japonica indicated 2.5 times as much as that of Dactyils glomerata. 2. Comparing the growths of Zoysia japonica among the temperature treatments, the results obtained were shown as below. 1) With a lowering the temperature from 34/29℃ to 19/14℃, the first tiller appeared more slowly and tiller numbers per plant decreased remarkably. 2) In 34/29℃ plot, the first elongated internode was observed in the 6th internode on the main stem at 49 days after germination, but appearance of the first elongated internode was markedly late with a decreasing temperature. The number of compound nodes and length of the stolon per plant were the most at 29/24℃ plot, however, they were markedly reduced at 24/19℃ plot. 3) The dry weights of leaf, stem and root were the heighest at 29/24℃ plot respectively, but all of them decreased with a decreasing temperature. Especially, the root weight was reduced, markedly. 3. Based on these results, we have discussed about the advisable method to make the seedling establish, survive and expand for the improvement of Zoysia type grassland.

View full abstract

A series of field experiments was undertaken to assess changes in some structures of a pasture ecosystem due to cessation of grazing. This report deals with the changes of the numbers of microorganisms in 0-10cm soil layer of the following three experimental plots; Control plot: managed by rotational grazing; Ca-exclosure plot: no gazing from 1976 to 1980, with CaCO_3 (2ton/ha) application at the beginning of the period; Exclosure plot: no grazing without application of CaCO_3. Furthermore the properties of soil microorganisms in each plot were compared with that in the forest soil which was sampled from the adjacent deciduous broadleaved forest dominated by Quercus serrata in 1980. The experimental results obtained were as follows. 1. The number of bacteria in control plot showed the positive correlation with soil moisture, and the number increased gradually from spring and reached maximum in autumn. In both exclosure plot, however, such correlation and seasonal change as seen in control plot were found slightly in the second year of the period, but not at all in the fifth year. 2. There was no correlation between the changes in the numbers of actinomycetes and fungi and those of soil moisture in the all plots examined. 3. No significant differences in the numbers of soil microorganisms were observed among the all plots, except that the number of fungi in Ca-exclosure plot decreased in the fifth year as compared with that in control plot. 4. There was no relationship between the numbers of microorganisms and moisture in the forest soil. Such a property of microorganisms in the forest soil was like that in both exclosure plots at the fifth year. These results were discussed in relation to applying fertilizer and grazing of cattle.

View full abstract

A series of field experiments was undertaken to assess changes in some structures of a pasture ecosystem due to cessation of grazing. This report deals with the changes of total C, total N and exchangeable Ca contents in 0-20 cm soil layer of the following three experimental plots ; Control plot: managed by rotational grazing; Ca-exclosure plot: no grazing from 1976 to 1980, with CaCO_3 (2ton/ha) application at the beginning of the period; Exclosure plot: no grazing without application of CaCO_3. Furthermore the chemical characterristics of the soil in each plot were compared with those of the forest soil which was sampled from the adjacent deciduous broadleaved forest dominated by Quercus serrata in 1980. The experimental results obtained were as follows: 1. Total C and total N contents in 0-20cm soil layer increased slowly with the rest period of grazing, and the rate of the increment of total N content was relatively greater than that of total C content. Concequently, C/N ratio in 0-20cm soil layer decreased in both exclosure plots as compared with that in control plot.2. Exchangeable Ca contents in 0-15cm soil layer of both exclosure plots were much higher than that of control plot at the, fifth year, but there were no differences in exchangeable Ca contents of 15-20cm soil layer in the all plots. 3. Total C, total N and exchangeable Ca contents in 0-20cm soil layer of the forest were higher and C/N ratio was lower than each of control plot. Such soil chemical characteristics of the forest were approximate to those of both exclosure plots at the fifth year. From the results in the present and previous reports, it was assumed that each structure of permanent pasture soil might revert to the structures of the forest soil in their peculiar processes, if human activities such as fertilizer application and cattle grazing, which had had maintained the steady-state of the pasture ecosystem, were left off.

View full abstract

This experiment was carried out to find the effect of different levels of nitrogen and potassium fertilization on pasture on mineral contents in grass and grazing sheep serum. Orchardgrass sward was divided into four blocks, following to the amount of nitrogen and potassium fertilizers: N 100kg and K_2O 100kg (per ha) in block I, N 100kg and K_2O 600kg in block II, N 400kg and K_2O 100kg in block III and N 400kg and K_2O 600kg in block IV, respectively. Each block was sub-divided into four paddocks for rotational grazing. Each paddock was grazed five times for about 7 days in each time by 3 wethers. The dressing amount of each time was one-fifth for yearly amount. The mineral contents in herbage were as follows: on the average throughout the grazing period, 2.68, 2.61, 3.67 and 3.42% for nitrogen, 0.45, 0.44, 0.37 and 0.35% for phospho rus, 3.36, 4.22, 3.82 and 4.53% for potassium, 0.25, 0.23, 0.27 and 0.22% for calcium and 0.19, 0.181 0.22 and 0.19% for magnesium in block I, II, III and IV, respectively. Seasonal change was observed in mineral contents of herbage. In early spring, nitrogen content in herbage was higher, but calcium and magnesium contents were lower than these in the other period. Calcium and magnesium contents in herbage increased with season advanced. Phosphorus content in herbage of block I and II was higher in summer than that in spring, while this content in block III and IV was reversely lower in summer. Seasonal change of potassium content in herbage was not observed clearly. The concentration of urea-nitrogen and minerals in blood serum were as follows: on the average throughout the grazing period, 26.4, 25.4, 31.0 and 29.0mg/dl for urea-nitrogen, 5.40, 5.89, 6.43 and 5.60mg/dl for inorganic phosphorus, 21.9, 21.9, 20.9 and 20.9 mg/ dl for potassium, 10.6, 10.2, 10.3 and 10.3mg/dl for calcium and 2.39, 2.23, 2.29 and 2.29 mg/dl for magnesium in block I, II, III and IV, respectively. The concentration of urea-nitrogen in serum was higher in block III or IV than that in I or II, but the effect of different levels of nitrogen and potassium fertilizers was not observed clearly in those of other elements. The concentration in some of these elements in serum was changed rapidly after pasturing: namely, urea-nitrogen concentration increased on one day after pasturing in all blocks, and calcium, inorganic phosphorus and potassium concentrations depressed on 2 or 3 days after pasturing. But, depression of magnesium concentration in serum after pasturing was not found clearly in this experiment.

View full abstract

Effects of the amounts of nitrate of the ensiled material on silage quality were investigated with bag silos (50kg capacity). In two blocks (A and B), in which orchardgrass previously treated with four levels of N fertilizer (0, 5, 10 and 20kg/10a) were used as materials, the addition of potassium nitrate at the rate of 0, 0.15 and 0.30% of ensiled grass were compared. The silages made with nitrate addition at ensiling were always of good quality with no butyric acid, high lactic acid and low pH and NH_3-N. Also, increasing nitrate content of the ensiled grass by the level of higher N fertilizer resulted in good quality silages. The amounts of gaseous loss were decreased by nitrate addition, whereas those of top spoilage loss were increased. The counts of yeasts and clostridia were reduced by nitrate addition. It is concluded that, therefore, high nitrate content in material contribute to improve silage quality.

View full abstract

The two varieties of corn, HEIGENWASE and HOKUYU were harvested at late dent stage with a corn harvester at two theoretical cuts of 5 and 10mm and ensiled in stacks, and the digestibilities and nutritve values for dairy cows were compared between 5 and 10mm cut silages. The actual cutting size was about twice as long as the theoretical value on an average, and in 5mm cut silages the ratios of over 7mm-sized ones to the total were below 50%, where-as, the ratios were 58〜65 % in 10mm cut silages. The fermentative quality of silage was better for 5mm cut silages than for 10mm cut ones. The digestibilities of starch were significantly higher for 5mm cut silages than for 10mm cut silages. There were no significant differences in the digestibilities of dry matter, organic matter and crude protein, and in the contents of DCP, TDN and DE between 5 and 10mm cut silages.

View full abstract