Abstract
An investigation was made to clarify the effect of aspects on seedling establishment and forage production of temperate grasses at lowland hillside in southern part of Kyushu. The study sites were on north and south aspects of slopes which were both about 25°-30° angles, at about 400m of altitude in Miyazaki prefecture. A mixture of seeds composed of perennial ryegrass (Lolium perenne L.), tall fescue (Festuca arundinacea Schreb), kentucky bluegrass (Poa pretensis L.), redtop (Agrostis alba L.) and white clover (Trifolium repens L.) was seeded on September 11, 1979. Seedling establishment was observed and herbage was harvested about once a month during growing seasons in 1980 and 1981. Daily soil temperature at 5cm depth and soil moisture at 2-7cm depth were measured several times a year from Sept. in 1979 to Oct. in 1981. Results were as follows: 1. Seedling numbers of grass species and white clover measured at five weeks after seeding were far less on south than on north aspect, and seedling growth was depressed on south aspect. 2. Total forage yield was significantly lower on south aspect in both 1980 and 1981. Total forage yield of grasses on south aspect was about half that on north aspect. 3. South aspect showed more rapid deterioration of grass species, especially perennial ryegrass, and showed more rapid invation by weed species. 4. On south aspect, conbination of high soil temperature and low soil moisture during summer to early autumn appeared to limit germination and seedling growth, and to cause deteriolation of temperate grass species.
