Soil properties are important environmental conditions affecting fruit quality and yield in new cultivars of Actinidia arguta. The yield of three A. arguta cultivars (cv. Autumn Sense, cv. Chungsan, and cv. Greenball) from Wonju city, South Korea was investigated from 2017 to 2019 and the relationships to soil properties are discussed. The yield of cv. Autumn Sense, cv. Chungsan, and cv. Greenball fruits ranged from 6.8 to 24.5, 14.0 to 29.0, and 10.5 to 38.5 kg/vine. cv. Autumn Sense had the highest soil organic matter content and soil C/N ratio over the three-year period. The yield of A. arguta fruits was positively correlated with soil C/N ratio and could be described by a power model (y = axb), suggesting that soil C/N ratio plays an important role in limiting the bioavailability and bioaccumulation of organic matter in A. arguta fruits. In addition, C/N ratio in the soil was influenced by the soil available phosphate. However, the threshold of the C/N ratio for A. arguta fruit differed according to cultivar, and especially the lowest threshold was observed in cv. Chungsan. Therefore, the application of an appropriate C/N ratio depending on the cultivar is required for improved fruit yield. Our results present the soil properties required to increase the yield of the new A. arguta cultivars in South Korea.

The road slopes have various problems such as the risk of landslides and soil erosion, and research on stabilizing road slopes using plant greening has attracted the most attention. The overall objective of this research was to evaluate the effects of woody biomass based growing media on plant germination in a slope area. Moreover, we tried to find out what physicochemical properties of growing media affect plant germination on a slope. For experiment, we tested soil, soil mixed with growing media (1:1, w/w), and growing media by itself. Physical and chemical properties were evaluated after a month from the date of treatment application to the experimental slope site. Plant germination of Lespedeza cyrtobotrya was measured for plant growth evaluation. Physicochemical properties were altered by mixing the soil with growing media. Particularly, moisture content, organic matter and C/N ratio were significantly changed in soils mixed with growing media compared to soil alone. We confirmed that plant germination was high when growing media was mixed with the soil. There was a significant linear relationship between particle density and pH of all media tested and plant germination. In addition, in the same trend, the principal component analysis confirmed that the particle density and pH was positive component for plant germination rate, and the C/N ratio was found to be the negative component for plant germination. In conclusion, the particle density, pH and C/N ratio of the soil mixed with growing media was considered effective for plant germination in the experimental slope site, and this wood-based growing media provides a means to improve the harmony between the slope and the surrounding environment.

Light is an important factor for cordycepin production in Cordyceps militaris. We investigated the effects of different light-emitting diode (LED) conditions including various LED wavelengths and their combinations on cordycepin production in Cordyceps militaris cultivated in submerged culture. The results of our study showed that the combinations of LED wavelengths were more beneficial than single LED sources for cordycepin production. Among the three tested wavelength combinations, the greatest effects for cordycepin production were observed for the red:blue light combination at the wavelength ratio of 5:5 or 3:7. The optimal culture conditions were 19.2278 h/day of illumination time; 9.19497 g/50 mL of glucose content in the media; and 53.112 h of cultivation time. Our model predicted a maximum yield of 2860.01 μg/mL cordycepin. Finally, to verify the calculated maximum, we performed experiments in the culture media representing the obtained optimum combination and the cordycepin yield of 2412.5 μg/mL.