Abstract
Investigations on the changes in yields and the decay in number of plants due to the summer depression of growth of some northern type grasses and legumes in Seto-uchi district were carried out in 1959〜62. Six kinds of grasses and legumes were tested; namely, ladino clover, red clover, alfalfa, orchard grass, Kentucky 31 fescue and reed canary-grass. Fertilizers were applied as shown in Table 1. The results were as follows: (1) As shown in Table 3 and Fig. 2, in most of the species, yields in the 3rd year declined to 50%〜70% of those in the 1st. (2) In the relative decay in number of plants due to the summer depression of growth, there were distinct differences among the crops as shown in Table 4. The number of plants in stands of alfalfa, Ky. 31 fescue and reed canarygrass was superior to that of all others and good stands remained throughout the period. (3) Heavy application of fertilizer exerted harmful influences upon the persistency of ladino clover, red clover and orchard grass which were sensitive to the summer depression of growth.
