メロンの養分吸収に関する研究 (第9報)

1. To clarify the suitable amounts of soils with different properties for muskmelon cultivation, ten plots which consisted of factorial combinations of five levels of soil weight (10, 15, 20, 25 and 30kg per plant), and two kinds of soil property (sandy soil and clayey soil) were established, and effects of these treatments on the growth, fruit weight and quality, and accumulations of the five elements in the whole plant were investigated.<br>2. With increasing soil weight from 10 to 30kg per plant, the growth of plant as measured by the dry weight of the whole plant, fruit weight, and accumulations of the five elements in the whole plant increased. On the contrary the pH, electrical conductivity, NO₃-N concentration, available phosphorus, exchangeable potassium and calcium of the soil decreased. Using the clayey soil, the growth of the plant and the accumulations of the five elements in the whole plant increased and the fruit showed favourable external appearance On. the contrary the pH, NO₃-N concentration, and electrical conductivity lowered in the cleyey soil.<br>3. The growth of the plants, the weight and quality of the fruits in the plots of S-10, S-15 and C-10 were slightly inferior to those in the other plots. These results seemed to be highly correlated with the electrical conductivity of the soil. Judging from these results, the suitable amounts of sandy soil and clayey soil for muskmelon cultivation under the fertilization management previously described seemed to be more than 20kg and 15kg per plant, respectively.<br>4. To clarify the suitable amounts of soil under the different spacings between plants for muskmelon cultivation, nine plots which consisted of factorial combinations of three levels each of soil weight (15, 20 and 25kg per plant), and spacing (44. 5, 41.5 and 38.5cm between plants) were established using the sandy soil, and effects of these treatments on the growth, fruit weight and quality, and accumulations of the five elements in the whole plant were investigated.<br>5. Though the growth of the plant as measured by the dry weight of the whole plant, fruit weight and accumulations of the four elements in the whole plant were slightly greater in 20 and 25kg soil weight per plant than those in 15kg soil weight, the differences of those in 20 and 25kg soil weight were not significant.<br>6. Though the growth of the plant, fruit weight, and accumulations of the four elements in the whole plant were slightly smaller in 41.5 and 38.5cm spacing than those in 44.5cm spacing, the differences of these in 41.5 and 38.5cm spacings were not significant.<br>7. With decreasing soil weight from 25 to 15kg per plant, the electrical conductivity and NO₃-N concentration of the soil increased. This increased electrical conductivity seemed to be highly correlated with the slightly depressed growth, and the light brownish roots, which were observed in the plots of 15kg soil weight.<br>Judging from these results, the suitable amounts of sandy soil for muskmelon cultivation seemed to be 20kg per plant under the 38.5cm spacing between plants.