Effects of the physical and chemical properties of soils derived from different matrices on the growth of Satsuma orange trees. I

Abstract

1. In order to investigate the effect of the physical and chemical properties of soils derived from different matrices on the growth of Satsuma orange trees, the pot experiment was carried on with 2-year-old Miyagawa wase oranges for 4 years of 1957_??_1961. Soils examined were collected from the uncultivated lands of main citrus raising area in Ehime Prefecture. The kinds of soils and their matrices were as follows: (i) Idai soil; Granodiorite, (ii) Tobe soil; Crystalline schist (graphitic), (iii) Sekizen soil; Paleozoic graywacke and lime stone, (iv) Yoshida soil; Mesozoic sand stone, (v) Ono soil Diluvial, and (vi) Ono volcanic ash soil; Volcanic ash.2. The shoot growth, fruit yield and enlargement of trunk circumference were all the greatest in Satsuma orange trees planted in Sekizen soil throughout the experimental term. In the second vear, no significant differences of the shoot growth was found among the five soils except Sekizen soil. In the third year, Yoshida soil, Ono soil and Ono volcanic ash soil were all superior in the shoot growth to Idai soil and Tobe soil, while the formers were inferior in the fruit yield to the tatters. In the fourth year, the shoot growth, trunk circumference and yield were all better in Yoshida soil, Ono soil and Ono volcanic ash soil than in Idai soil and Tobe soil.3. The best growth in Sekizen soil might be attributed to the chemical properties of the soil which was slightly acidic or alkaline, and rich in exchangeable cations, nitrogen applied being very effective. In the five soils except Sekizen, the chemical properties of soil such as cation exchange capacity, soil reaction, and contents of organic carbon, total nitrogen, exchangeable cations and phosphorus (water soluble, 0.002N-H2SO4 soluble and total) had no direct connection with the tree growth. Yoshida soil was strongly acidic, and Ono volcanic ash soil was extremely low in cation saturation. Nevertheless, the tree growth in both of them was not very bad, probably due to the high effectiveness of nitrogen applied under such a pot culture. Idai soil contained abundantly fine or small gravels, and Tobe soil was rich in large gravels. So, the poor growth of the trees planted in them might be a result of the marked leaching of nitrogen from them.Finally, it will be concluded that the growth of Satsuma orange trees planted in soils of different matrices may be mainly affected on one occasion by their physical properties and on other occasion by their chemical properties.