Year-round Soil Water Quality Characteristics of an Apple Orchard in a Snowy and Cold Region Considering the Dormant Period

Abstract

The purpose of this study is to understand the behavior of macronutrients such as nitrogen, potassium and magnesium in apple orchards with gravelly brown forest soil in snowy and cold region. During from 2016 to 2020, including the period of snow cover and melting, which is the dormant period of apple trees, soil pore water was collected by porous cup and syringe from a depth of 10 to 70 cm in the apple orchard ones to three times per a month. pH, EC and the concentration of ion species of the sampled pore water overtime were measured. In May-September 2019, when the amount of precipitation was less than usual year, soil drying was remarkable, and reflecting the suppression (antagonistic effect) of magnesium uptake accompanying the promotion of potassium uptake in roots of apple tree, and the potassium-concentration of soil pore water was low. Therefore, the condition showing low concentration of potassium and high concentration of magnesium continued. The NO₃-N concentration in the soil pore water during the snowmelt period was higher than the after leaching by rainfall during the growing period. In addition, significant leaching of NO₃-N was observed due to the infiltration of snowmelt water at the end of the snowmelt period. However, it was revealed that the roots of apple tree are in a nutrient condition that enable to sufficiently uptake the NO₃-N remaining in the soil pore water after the dormancy breaking of apple tree. It was suggested that by continuing to understand the characteristics of year-round changes in soil pore water quality, it is possible to estimate the mode of nutrient uptake from apple tree roots.