Burrowing of cave-dwelling small mammals in grasslands disturbs soil and vegetation, and is also affected by soil and vegetation in grasslands. In this study, we examined the relationships between soil - vegetational characteristics and burrowing of small mammals in a mountainous grassland in the Tohoku region. We established a 200 m line in the pasture and measured the presence or absence of burrow openings, slope angle, dominant plant species, mean sward height, plant coverage, litter thickness, soil moisture content and soil hardness at 100 locations along the line by setting a quadrat (50 cm×50 cm). Using these measurements, logistic regression analysis was conducted with the presence or absence of burrow openings as the objective variable. Independent variables selected by the analysis were litter thickness, plant coverage, mean plant community height, and dominant plant species, where only the litter thickness was significant (P < 0.05). These variables have a function to conceal burrow openings, suggesting that small mammals used to burrow in pasture soils which are suitable for avoiding predators by the conditions.

Wheat (Triticum aestivum) dwarf bunt disease by Tilletia controversa, widely spread throughout Hokkaido, has grievously damaged wheat production in Hokkaido, where wheat is widely cultivated mainly in upland dairy-field areas. In these areas, temperate grasses and forage crops such as rye are cultivated in neighbouring dairy fields. Therefore, these plants can transmit T. controversa and can influence the dwarf bunt occurrence in wheat. This study elucidated T. controversa pathogenicity for four temperate grasses (Lolium perenne, Dactylis glomerata, Phalaris arundinacea, and Phleum pratense), rye (Secale cereale), and triticale (a wheat-rye hybrid) by inoculating fields with T. controversa chlamydospores from an infected field in Hokkaido. Results show that T. controversa had no pathogenicity for the tested four temperate grasses and only slight pathogenicity for rye and triticale. However, the percentages of bunted heads for rye and triticale were much lower than for the two wheat cultivars. We could conclude that the four temperate grasses are unlikely to transmit T. controversa, which suggests no need limiting the cultivation of these grasses for fear to mitigate the disease, while further risk assessments are needed for rye and triticale.

In southern Kyushu, forage corn varieties were tested for grain production in spring seeding. This research was carried out in 2018 and 2019. Herein, 28 varieties from relative maturity (RM) 105 to 129 were evaluated for root rot rate, lodging rate, and stalk breakage rate at the yellow- and full-ripe stages, as well as grain yield at the full-ripe stage. Tukey test classified 15 varieties in the highest grain yield group in two years. And the top eight varieties with the highest average grain yield over two years produced more than 900 kg/10 a. Furthermore, four varieties were chosen as suitable varieties for spring seeding in southern Kyushu due to their high grain yields and strong resistance to lodging, stalk breakage, and root rot. Additionally, grain yields at full-ripe stage were correlated to ear yields at yellow-ripe stage. Therefore, varieties with high ear yields at the yellow-ripe stage from a result of the past results of performance test were assumed to have high grain yields at the full-ripe stage.

Crude protein in grasses is an essential nutrient that affects the growth of dairy cattle and the quality of milk produced by the cattle. Moreover, there has been demand for non-destructive measurement technology for measuring grass crude protein content. In this study, we investigated the relationship between the crude protein content and vegetation index of Rhodes grass (Chloris gayana Kunth.). A fertilization experiment was conducted using chemical fertilizers at six levels of nitrogen input in 2018. We used an indoor spectrophotometer to measure the reflection spectrum of Rhodes grass fresh leaves and calculated the two types of vegetation indices, normalized difference vegetation index (NDVI) and green normalized difference vegetation index (GNDVI). The nitrogen content was measured using the Dumas method, with the instrument of a total nitrogen analyzer and total carbon analyzer. We clarified the relationships among the fertilization date, nitrogen input level, and harvesting date. The crude protein content varied from 5.8% to 22.1%. The coefficients of determination of GNDVI and NDVI were 0.88 and 0.73, respectively, and the root mean squared errors of GNDVI and NDVI were 1.7 and 2.6, respectively. Therefore, we demonstrated the potential of estimating crude protein content in Rhodes grass by spectral reflectance.