温州ミカン園土壌の経年変化について

抄録

In this paper, the author deals with the successive changes of some soil properties caused by the cultivation of citrus trees. The data are obtained, from the soil survey in the important area of the citrus production in Nagasaki Prefecture during 1960-61. The orchard soils in the area are derived from the similar parent materials (weathering product of the andesite) on the steep slope, and cover different stages of development, from younger to older, in citrus cultivation. The results are summarized as follows: 1) According to the morphological characteristics of the soil profiles, these orchard soils could be divided into the following three stages of development which are represented by their horizon sequences: i) A/B (young soils), ii) A_1/A_2/B (most of orchard soils), and iii) A_1/A_2/B_1/B_2 (well drained orchard soils). It seems that A horizon becomes to differentiate into A_1 and A_2 subhorizons by tillage.