Abstract
In the community of grass sward, individual plants are competiting with one another and inferior plants gradually fade away in the progress of competition. Thus the status of distribution of stubbles in grass swards seem to be changed by the extent of competitive pressure among individuals.In this research, the relation between stubble size and the distance among stubbles and the disposals of different size of stubbles were investigated in fall of 1971, in order to know the status of distribution of stubbles in orchardgrass sward. The swards investigated in this study have passed for three years after sowing, and the vegetational structure (density, basal coverage and the distribution of stubbles etc.) have been changed by the different amounts of fertilizer application. The results were summarized as follows ; 1) In this study, the diameter of stubble was adopted in order to indicate the stubble size. High correlation was shown between the diameter of stubble and the number of tillers in a stubble (Fig.2) 2) About same size of two stubbles being adjacent each other, the relation of the distance between stubbles and the diameter of stubbles were examined. There were high correlation between the distance and the diameter of stubbles, and following regression was obtained ; D=1.177R^<1.111> γ=0.949 (D…distance between stubbles, R…diameter of stubbles) 3) In swards which various size of stubbles were distributed, it has an inclination that large stubbles situated in the distance with one another and small stubbles situated near or among large stubbles (Fig.4 and 5). 4) From the results described above, it was discussed that density and basal coverage in grass sward should be described not only the number and the degree of coverage in unit area, but also relationship between the stubbles size and the distance between stubbles.
