Effects of cumulative fertilization pattern on growth and nutrient concentrations of Chamaecyparis obtusa seedlings

摘要

The objective of this study was to investigate plant growth and nutrient uptake of Chamaecyparis obtusa seedlings with heavy fertilization treatment depending on previous fertilization experience. In a previous year, one-year-old Chamaecyparis obtusa seedlings were planted at a nursery with two levels of fertilization: the first group was fertilized with a mixed nitrogen–phosphorus (N-P) fertilizer of N 41.4?g m~(?2), P 18.3?g m~(?2) and the second group was unfertilized as a control. After one year, seedlings of similar height and root diameter were planted into 30-l pots and underwent two treatments: no fertilization for control and heavy fertilization with Basacote? 80?g pot~(?1). In the control, the plants’ growth exhibited no differences according to previous fertilization experience; in the case of heavily fertilized plants, seedlings which had experienced previous fertilization showed a 29% increase in height and a 63% increase in above-ground biomass production than did seedlings with no fertilization in the previous year. The biomass allocation to below-ground was low for the heavily fertilized seedlings regardless of previous treatments. N and P concentrations of the seedlings, measured at the leaf and root, were irrelevant to previous fertilization, but were higher in the heavily fertilized plants. This study suggests that previous fertilization experience at the nursery stage may reduce the stress induced by initial heavy fertilization during out-planting.