Abstract
It seems to be very important for the good managemhnt of sown grassland to diagnose its current condition and to estimate tne trend of changes to come. In this experiment the changes in the conditions and the trend on orchardgrass sward were studied under different cutting frequencies (3, 4 and 5 times of cutting for a year) and the different levels of fertilizer application (1, 2 and 4kg/a of NPK were applied for a year) from 1968 to 1969. The results were summarized as follows ; 1) In the plots with 3 times of cutting and 4kg/a application the number of stubbles and the basal coverage decreased gradually but the diameter of stubbles increased comparing with the other treatments and grass type became more erect comparatively. 2) In the plots with 5 times of cutting and light fertilizer application (1k/a) the number of stubbles and basal coverage were maintained but the subbles were comparatively small in size, and prostrate plants became dominant. 3) As above mentioned, by the difference of cutting frequency and the amount of fertilizers, the condition of orchardgrass sward changed into various states in a short time of two years. Number of stubbles, diameter of stubbles, basal coverage and grass type changed remarkably corresponding to the yield level of sward and the management to grassland. 4) Plant height and length of leaf blade showed high correlations with weight of standing crops, but number of tillers did'nt.
