2020 Volume 91 Issue 3 Pages 137-146
In this study, the effects of agricultural management, such as nutrient management practices and tillage, on the accumulation and consumption of some elements in the arable Andosols of Tokachi district, Hokkaido, were investigated. The researchers collected soil samples from soil profiles of Low-humic Andosols (Typic Hapludands) and Cumlic Andosols (Pachic Melanudands) and compared the vertical distribution of the total elements in uncultivated virgin soil and cultivated upland soil. The net accumulation or consumption of each element in the arable soil was calculated, while the bulk densities and the differences in the thickness of the layers between the cultivated and adjacent virgin soil were also accounted for. In the virgin soil, the amount of each element on the basis of soil mass was attributed to soil formation processes and parent materials in the virgin soil, while cultivated soil was strongly affected by physical disturbances in the plow layer and elemental inputs from fertilizers. The vertical distribution of each element indicated that the amounts of C, N, P, Ca, and Cd were large in surface soil, while the amounts of K, Mg, and Zn were large in subsoils. The net consumption of C and N in the cultivated Andosols was observed; remarkably, the consumption of C in the plow layer of the Cumulic Andosols was 124 Mg ha−1. The net accumulation of P and Cd in the plow layer of cultivated soil was 3.5–4.6 Mg ha−1 and 350–569 g ha−1, respectively, which was remarkably large; this suggests that most of the Cd may have accumulated through heavy phosphate fertilization. The accumulation and/or consumption of K, Mg, and Ca were also observed in the cultivated Andosols, which implies that appropriate plant nutrient management is critical to avoid the exhaustion of these elements that are essential for plants.
