A model using meteorological data was proposed for estimating the seasonal changes of the Normalized Difference Vegetation Index (NDVI) of meadow steppe in Inner Mongolia, China, which was obtained from the Advanced Very High Resolution Radiometer (AVHRR) onboard the National Oceanic and Atmospheric Administration (NOAA). The production of grassland is affected by seasonal changes in meteorological factors. Aboveground biomass changes should be reflected in seasonal NOAA/NDVI changes (⊿NDVI). So, we estimated the seasonal NOAA/NDVI changes of meadows in Inner Mongolia grassland using meteorological data from mid April (growth of plants starts) to mid August (post-maturity and before cutting). The model is based on simple and multiple regressions, and independent variables with ⊿NDVI in each 10-day period, dependent variables with a mean air temperature (T_α, ℃) and the sum of the precipitation (P_α,mm) in period α where α is followed by 6 different periods as if τis the same period as with ⊿NDVI measured ; 1=τ,2=(τ-1), 3=(τ-2), 4=τ+(τ-1), 5=(τ-1)+(τ-2), 6=τ+(τ-1)+(τ-2). In this case, τ is the same 10-day period of the estimated ⊿NDVI. Here, numbers in parenthesis is reflecting the number of 10-day periods measured ⊿NDVI. ⊿NDVl can be obtained by two simple regressions and one multiple regression which is divided into the following three phases : S_1) Initial growth phase (mid April to mid May), ⊿NDVI=0.001053+0.000118 T_5 (R^2=0.122, P<0.05) S_2) Flushing growth phase (late May to early July), ⊿NDVI=0.008358+0.000071P_5-0.000342T_5 (R^2=0.169, P<0.05) S_3) Maturity phase (mid July to mid August) ⊿NDVI=0.01918-0.000943T_6 (R^2=0.235, P<0.01) Using these results, seasonal NDVI changes were simulated by the following equation. NDVI=NDVI_0+Σ⊿NDVI×10 where, NDVI_0 is the initial value observed in early April. The results of calculations on seasonal NDVI revealed that the error between the observed NDVI and the estimated NDVI was 12.9% (R^2=0.912, P<0.001). In order to verify this model, we constructed models for 7 years, and tested them with the meteorological data of the excepted year. As a result, it was suggested that the present model can be used for the other years as well.

View full abstract

The effect of sowing date and competition with orchard-grass (Dactylis glomerata L.) on the seed emergence and growth of horsenettle (Solanum carolinense L.) was investigated. Horsenettle seeds were sown in plastic containers that were filled with soil and placed outdoors. The sowings were conducted at approximately monthly intervals from April through August in 1996 under conditions with (OG) and without (BARE) orchardgrass sown in April 1996. With the exception of July sowing, cumulative percentages of emergence for horsenettle approximately two months after sowing in BARE were 80% or higher for all sowings. In OG, the emergence percentages for April and May sowings were higher than 45%, while the percentages for the remainder were nearly zero. Most of the seedlings for April through June sowings in BARE overwintered and resorouted in May 1997. In OG, almost no re-sorouted shoots were observed in any of the sowings. It was found that the earlier the seeds were sown, the greater the horsenettle growth was in September 1996 and May 1997 .This trend was prominent in BARE. The horsenettle growth in OG was much less than that in BARE. The trend of horsenettle growth in September agreed well with that of the re-sorouted shoot number in May of the next year. From these findings, it was suggested that horsenettle seedlings rarely become established in pastures thick with orchardgrass.

View full abstract

New methodology was developed to investigate bite weight and bite force of sheep using simulated swards, hand-constructed from bunches of orchardgrass (Dactulis glomerata L.) leaves spaced 15cm apart. These leaves were attached to the 5 three-directional loadcells with 6mm iron bolts for a measurement of bite force. Three Suffolk wethers with a mean live weight of 35kg were used. Experimental variables in two studies were levels of applied nitrogen (nil, 100 and 200kg/ha) and leaf densitv (462 leaves/m^2 in Expt. 1 and 1026 leaves/m^2 in Expt. 2). Applied nitrogen increased width, thickness, DM weight per unit length and breaking force per leaf. Mean bite force per leaf was 9.8±0.80N in Expt. 1 and 6.8±0.53N in Expt. 2, compared with the higher mean of 15.4±0.75N of tensile strength of leaves. Bite number per min, and DM intake rate decreased with increasing nitrogen application, especially at high leaf density. DM intake per bite at high leaf density was approximately double that at low leaf density. DM intake per unit force was 2.5-4.1mg/N at high leaf density and 1.2-2.2mg/N at low leaf density.

View full abstract

The objectives of this study were to confirm the selective incidence of speciflc snow mold fungi by controlling other fungi with fungicides in the field and to evaluate genetic resources of meadow fescue (Festuca pratensis Huds.) in terms of resistance to typhula snow mold. Due to its simplicity and reliability, treatment of iminoctadinetriacetate would be useful for selecting varieties for resistance to typhula snow mold in meadow fescue. Some Russian varieties that showed high survival rates in the present study are considered promising as breeding materials for winter hardiness.

View full abstract

The generation of haploids in most grass species is relatively infrequent, but has continually been considered a potential tool for the development of fixed inbred lines, a method for cytoplasmic transfer, or polyploid genome manipulations. This study was originally undertaken to identify the frequency of successful hybridization following crosses between Poa arachnifera×P secunda. However, during the research, four androgenic haploids representing the polyploid P.secunda parent were obtained with varying chromosome numbers. Each of the haploids exhibited the fibrous root system characteristic of the P secunda parent. The generation of androgenic haploids offers an opportunity to observe P.secunda germplasm in a P arachnifera cytoplasm as well as an opportunity to utilize such materials in geneticbstudies of polyploid P.secunda.

View full abstract

Three cultivars, including one high-Mg and two commercial cultivars from each of Italian ryegrass, orchardgrass and tall fescue grown under solution culture condition were evaluated for minerals, viz., magnesium (Mg), calcium (Ca), and potassium (K) density by X-ray microanalysis. Three K treatments of 1.0, 5.0 and 25.0mM were superimposed on one-month aged seedlings for 10 days. Increasing solution K concentrations resulted an increase in shoot dry weight of the cultivars. All the high-Mg cultivars of three species showed higher Mg and Ca, and lower K density irrespective of K treatments. These high-Mg cultivars showed significantly higher Mg density in 5.0mM solution K level irrespective of species and experiments. Among the K treatments, cultivars of different species showed highest Mg density in 5.0mM solution K level. Increase or decrease in solution K levels from 5.0mM in the growing medium resulted a decrease in Mg density. There was no difference for Ca density between 1.0 and 5.0mM solution K levels while lowest Ca density was observed in 25.0mM solution K level. There was an increase in K density with increasing solution K concentrations. Consistent trend among the high-Mg cultivars of the three species for higher Mg density in 5.0mM solution K level within the species and experiments, suggests that while using X-ray microanalysis, 5.0mM level of K under solution culture condition is the best for screening plants with higher Mg density.

View full abstract

Energy dispersive X-ray microanalyzer (EDX) is efficient for individual selection of high-Mg plants by using ashed samples. Ashed sample preparation is time and labor intensive. This experiment was initiated for introducing X-ray microanalysis of fresh leaf tissues for individual selection and thus expedite the term necessary for sample preparation as well as individual selection. The approach was justified by using two tall fescue populations, HiMag and Kentucky 31 (Ky-31), having known differences in Mg contents. Plants were evaluated for mineral contents by energy reflectance X-ray fluorescence(ERF) analyzer and for relative densities of minerals in fresh leaf tissues (epidermis, fiber, mesophyll, phloem, vascular bundle sheath, xylem) by EDX analyzer. HiMag tall fescue showed higher Mg and Ca contents while lower K content than Ky-31 tall fescue. This trend was consistent for relative densities of minerals in different tissues of the cultivars. Among the tissues, mineral densities in xylem showed better correlations with whole plant mineral contents. Plants selected according to the higher Mg densities in xylem tissue had high Mg and Ca contents while low K contents, which indicates the high-Mg plants. This suggests the applicability of using relative density of minerals in xylem tissue for individual selection of high-Mg plants.

View full abstract

To generate expressed sequence tags (ESTs) in Italian ryegrass (Lolium multiflorum Lam.), we constructed seven directional cDNA libraries from mRNA prepared from various tissues (leaf, stem, inflorescence, and callus) and leaves under abiotic and biotic stresses such as heat-shock, cold-shock, and powdery-mildew (Blumeria graminis) infection. Clones were randomly selected from each library, and their 5 ends were sequenced to identify their putative functions. Out of 6751 sequences, 5922 (87.7%) were usable for database comparisons. Of these, 3244 clones (54.8%) showed sequence similarity with known genes from plants and other organisms. Analysis of the putative functions of these ESTs indicated that each of the seven cDNA libraries uniquely reflected the biological function and physiological status of their mRNA source. These results indicate that these ESTs will be useful resource for rapid gene identification and gene expression profiling in Italian ryegrass, and will facilitate genomics research of Italian ryegrass as well as other forage crops.

View full abstract

A collection of ten local populations of white clover (Trifolium repens L.), primarily from the old native grasslands of the northern Tohoku region, were transplanted as spaced plants along with three commercial cultivars Kent Wild, Huia and North White. Characteristic growth patterns and associations between plant characteristics and geographical factors were investigated for populations from the northern Tohoku region and compared with the commercial cultivars. Leaflet length, petiole length, internode length and stem thickness of the nine local populations with exception of KAMISODE-1 were smaller than those of the middle-leaved cultivar Huia. Principal component analysis was used to integrate these four morphological characteristics over two years of measurements, and the second principal component of the local populations demonstrated that the relative length of internode to the other three characteristics was shorter than for the three cultivars. In the nine small-leaved local populations, linear and quadratic relationships were investigated between all characteristics and three geographical factors (latitude, elevation and mean winter temperature). Winter survival showed significant fits with quadratic regression models against all three factors (p<0.05, p<0.01 and p<0.05, respectively). Moreover, winter survival is positively correlated to plant spreading (R^2=0.6329, p<0.05). SODEYAMA population collected from Iwate prefecture has the best winter survival and the largest plant spreading in the all small-leaved local populations.

View full abstract

Carbon dioxide (CO_2) is well known to be a "greenhouse gas" capable of causing significant climatic change. The optimum ranges of grass species are likely to shift as a result of climatic change. Accordingly, the optimum range for each species must be determined in order to select grass species that will grow in the new vegetation zones expected to result from climatic change. Changes in the cultivation limit and productivity of bahiagrass (Paspalum notatum Flugge) were estimated. The monthly dry matter productivity for each secondary grid square (approximately 10×10km) at the present time, 30 years and 100 years in the future was simulated by applying grid climatic data to the neural network model. The data were adjusted using the relationship between CO_2 concentration and net photosynthesis in order to evaluate the effects of rising temperature and increasing CO_2 concentration simultaneously. Then maps of suitable cultivation zone and productivity were drawn. These maps show that under present climatic conditions the cultivation zone of bahiagrass is limited to the south-western part of Japan, and dry matter productivity is about 0-3,000 g・m^<-2>・year^<-1>. In 100 years, the cultivation zone will extend northwards, and the dry matter productivity is predicted to increase to more than 3,000 g・m^<-2>・year^<-1> in most parts of the cultivation zone.

View full abstract

The relationships between various environmental factors and the appearance of Anthoxanthum odoratum and Carex albata in sown pasture were analyzed by discriminant analysis. Then correlations of coverages with soil pH, soil nitrogen concentration (soil N), and soil available phosphate concentration (soil P) were examined. Discriminant coefficients of soil moisture and slope degree against A. odoratum were positive, but the coefficient of soil hardness was negative. Coverage increased with decreases in soil N and P. On the other hand, in the case of C. albata, the discriminant coefficient of depth of humus layer was positive and the coefficient of soil pH was negative. C. albata coverage significantly increased with the decrease in soil pH. The results indicated that A. odoratum tends to grow well in conditions of low fertility such as on a steep slope but that it is susceptible to drought stress. Thus, enhancement of the competitiveness by fertilization would be an effective means to protect sown grasses against A. odoratum. On the other hand, the results indicated that C. albata prefers conditions of abundant nutrition and has a high level of tolerance to acid stress. Thus, modification of soil acidity, not fertilization, would be an effective mean to protect sown grasses against C. albata.

View full abstract

Recently, agricultural lands such as paddy fields, where cultivation was given up have been utilized as grassland for grazing or making hay. To manage such places skillfully, it is important to understand the area and how such fields are arranged. We therefore investigated arecently developed handheld GPS receiver (Garmin Corporation, eMap) to determine whether it could be used to survey the area and position of grasslands, and compared its use to the conventional glass fiber measurement tape. In the survey by GPS, the average errors which show a difference with a datum point were 1.18m and 0.63m, respectively at the time of a internal antenna and external antenna use. Moreover, the mean squared errors which show the variation in a survey value were 1.62m and 0.80m, respectively, based on the latitude and the longitude position coordinates. Thus, an external antenna raises the accuracy of a survey rather than an internal antenna. Although even in this case, the accuracy itself is not so high, the information about grassland shape, the area, and the perimeter distance were accquired with the same accuracy as measurements conducted using a tape measure. Furthermore, by using the GPS, we were able to obtain a survey map of the land where the target grasslands are widely dispersed from each other, in the same way as depicted by tracing aerial photographs. The hand held GPS receiver is also easy to handle and is a useful tool for acquiring rough information for practical grassland management.

View full abstract

We studied the effect of different levels of beet-pulp supplementation on nitrogen (N) intake, microbial N synthesis in the rumen, and duodenal flows of amino acids insteers grazing pasture. Three Holstein steers fitted with cannulas in the rumen and duodenum were grazed on orchardffrass (Dactylis glomerata L.) pasture and supplement with 0,15 or 30g/per metabolic body size of beet-pulp (BP0, BP15, BP30) in a 3×3 Latin square design. The pasture was divided into several paddocks, and the steers grazed each paddock for a day. The OM intake from pasture decreased with beet pulp supplementation but there was no difference in total OM intake among treatments. Total N and amino acid N intake decreased with beet-pulp supplementation (P<0.05). The ammonium N concentration in rumen fluid (mg/dL) was significantly lower in BP30 than in BP0 steers. Although duodenal non-ammonia N and amino acid N now did not differ among treatments, supplementing with beet-pulp decreased the N absorption from the rumen and increased the proportion of non-ammonia N and amino acid to duodenum.

View full abstract

Three hays of different cutting stage made from timothy were offered ad libitum to four Holstein cows in a 12 days changeover feeding experiments. In addition, 4.9kg of commercial formula feed was supplmented to each cow as dry basis. Three hays had TDN value of 59.5%(hay A), 55.8%(hay B) and 50.6%(hay C), respectively. The daily dry matter intake of hay varied from 8.5kg (hay C) to 10.3 kg (hay A). In this report, the ratio of the amounts in intake TDN with hay A treatment to hay B and hay C treatment was used as index for relative feed value estimation. The value of these index ware 85%(hay B) and 69%(hay C), respectively. The mean daily milk yields were 17.8kg in hay A, 16.4kg in hay B and 14.6kg in hay C treatment respectively. The milk protein and milk sugar (lactose) yields was significant higher (p<0.05) with hay A treatment than with hay C treatment, and this results was discussed that it may due to difference in the amounts of intake digestible carbohydrates between two hays.

View full abstract

Alfalfa weevil (Hypera postica Gyllenhal) is a serious pest of Chinese milk vetch, Astragalus sinicus L., which is a nectar source for the honeybee, in western Japan. Outbreaks of alfalfa weevil occurred in Saitama and Tochigi prefecture in 2002. The geographical distribution of alfalfa weevil was surveyed in the Kanto area excepting Kanagawa prefecture in the spring of 2003. Alfalfa weevil was found in the plains of Tokyo, Chiba, Saitama and Gunma prefecture, but not in the northern area of Ibaraki and of Tochigi prefecture. Alfalfa weevil larvae fed on common vetch, Vicia sepium, Chinese milk vetch, Astragalus sinicus L., red clover, Trifolium pratense L. and white clover, Trifolium repens L. Common vetch was the most popular host plant of the alfalfa weevil in the Kanto area. This weed grows on riverbanks, seacoasts, roadsides and vacant lands.

View full abstract

In order to examine the effect of different light quality on the germination of Echinochloa crus-galli (L.) Beauv. seeds and Digitaria adscendens (H.B.K.) Henr. seeds, the germination test was carried out under the conditions of green light, red light, far-red light, filtrated light through cheese cloth, full natural light, or dark. In addition, to examine whether phytochrome function is involved in the light effect on termination of both species, another germination test was carried out using seeds under the alternate radiation of red and far-red lights. In both species, the germination percentage was in the order of light≒filtrated light through cheese cloth≒redlight>green light>far-red light≒dark, there were significant differences among light qualities (p<0.05). In addition the promoting effect of red light on germination of both species was negated by far-red light. Oppositely the effect of far-red light on germination of both species was negated by red light. These results suggest that the promoting effect of lighton the germination of both species depends on red light. Also there is a strong possibility that phytochrome function is involved in the light germination of both species.

View full abstract

Ten cultivars of red clover (Trifolium pratense L.), including one foreign cultivar and nine Japanese cultivars or breeding lines, were tested for local adaptability at five different locations in Hokkaido from 1986 to 1989. Principal component analysis was applied to data on annual dry matter yields of the ten cultivars at the five locations during a period of four years. The locations were divided into two groups : one group of three locations in the northern or western part of Hokkaido and one group of two other locations in the eastern part of Hokkaido. The former group is in a snowy area, and the latter group is in a less-snowy, soil-freezing area. The ten cultivars were divided into two groups : one group consisting of six cultivars that showed good yield in the snowy area and one group consisting of four cultivars that showed good yield in the less-snowy soil-freezing area. The former group of cultivars showed relatively weak vigor at aftermath growing, while the latter group showed strong vigor. Red clover plants often suffer from clover rot in a snowy area but rarely suffer from clover rot in a soil-freezingarea. It could be concluded that the difference between the two groups of cultivars with respect to local adapatbility was due to the difference in their ability to resist clover rot caused by Sclerotinia trfoliorum.

View full abstract

We have developed a cutting round baler for the rice whole crop silage (five-row type,φ1,000mm) and have reported on its outline in a previous report. This report addresses a small round baler for the rice whole crop silage developed to miniaturize five-row type. This report examines its structure and performance. This small round baler also used the head-feeding combine as a base machine. Concretely, this small round baler is a self-propelled type using a rubber track and pretreatment equipment (divider, pick-up device, reciprocating knife, feed chain) of the head-feeding combine (operation width : 750mm). In addition, this small round baler is a direct-cut type which is attached with a bale chamber (fixed-chamber type : φ500mm) instead of a threshing device. For this small round baler, the number of bales was 80bales/10a., bale density was 90kgDM/m^3, and weight was 30kg when rice plants of 60% moisture content (yield : 3,300kg/10a) were baled. Harvesting and baling efficiency were 105min./10a. Bale density was low, but fermentation quality was excellent.

View full abstract

Ten local dairy farmers and 1,000 residents outside the area were sent questionnaires evaluating scenery in the northern Tochigi dairy zone ; seven farmers and 532 residents responded. Quantification II methods were applied to the responses. The element and category that serve as criteria for farmers and residents to evaluate the scenery as good or poor were similar. However, the ranking of elements for evaluating a scene and the weight applied to each category differed. Local dairy farmers strongly emphasized scene elements related to production activity or familiarity of life. For example, exposed livestock feces-and-urine compost, broken farm machinery and implements, and weeds clearly indicated a poor scene to farmers. In contrast, residents from outside the area selected evaluation criteria related to their images of the dairyzone. Scenes that were consistent with these images, such as a feeling of spaciousness, were rated as good.

View full abstract