Effects of Simulated Acid Rain on Growth and Physiological Characteristics of Ginkgo biloba L. Seedlings and on Chemical Properties of the Tested Soil -III. Effects on Chemical Properties of the Tested Soil-

인공산성우(人工酸性雨)가 은행(銀杏)나무 Ginkgo biloba L. 유묘(幼苗)의 생장(生長), 생리적(生理的) 특성(特性) 및 토양(土壤)의 화학적(化學的) 성질(性質)에 미치는 영향(影響) -III. 토양(土壤)의 화학적(化學的) 성질(性質)에 미치는 영향(影響)-

One-year-old seedlings of Ginkgo biloba were treated with various simulated acid rains(pH 2.0, pH 3.0, pH 9.0 and pH 5.0) to examine the effects of simulated acid rain on the chemical properties of the tested soil. The seedlings were grown in a pot($4500cm^3$)containing one of three different soils(nursery soil, mixed soil and sandy soil). Simulated acid rain was made by diluting sulfuric and nitric acid solution($H^1SO^4$ : $HNO^3$ =3 : 1, V/V) with tap water and tap water(pH 6.4), and treated by 5mm each time for three minutes during the growing seasons(April to October 1985). Acid rain treatments were done three times per week to potted seedlings by spraying the solutions. The chemical properties of potting media were compared among three soil types as well as among the various pH levels. The results obtained in this study were as follows : 1. Exchangeable calcium and magnesium contents and base saturation of the soil decreased with decreasing pH levels of acid rain, and their decreasing rates were as follows : sandy soil was the highest, followed by mixed and nursery soils, However, exchangeable aluminum content rather increased as the pH levels decreased. 2. Available phosphate in the soil decreased as the pH levels of acid rain decreased. Its content increased in nursery soil, compared with those before acid gain treatment, Gut decreased in mined and sandy soils. 3. Soil sulfate and nitrate contents increased remarkably as the pH levels decreased, and the only significant difference in the sulfate was found among the pH levels. Soil sulfate content was the highest in nursery soil, followed by mixed and sandy soils.

인공산성우(人工酸性雨)가 토양(土壤)의 주요(主要) 화학적(化學的) 성질(性質)에 미치는 영향(影響)을 구명(究明)하기 위하여, 천연강우(天然降雨)를 차단(遮斷)하고 묘포토양(苗圃土壤), 혼합토양(混合土壤) 및 사질토양(砂質土壤)에 각각 분식(盆植)된 은행(銀杏)나무 유묘(幼苗)(1-0, half-sib)에 인공산성우(人工酸性雨)(황산(黃酸)과 질산(窒酸)을 3: 1, v/v로 혼합(混合)하여 수도물로 희석한 pH 2.0, 3.0, 4.0 및 5.0) 와 수돗물 (pH 6.4)을 생육기간중(生育期間中)(1985년(年) 4월(月) 28일(日)~10월(月) 19일(日))에 주(週) 3회(回), 매회(每回) 5mm씩 처리(處理)하여 얻어진 결과(結果)는 다음과 같다. 1. 토양(土壤)의 치환성(置換性) Ca 및 Mg 함량(含量)과 염기포화도(鹽基飽和度)는 pH 값이 낮을수록 감소(減少)하였고, 감소율(減少率)은 사질토양(砂質土壤), 혼합토양(混合土壤) 및 묘포토양(苗圃土壤)의 순(順)으로 크게 나타났으며, 치환성(置換性) K와 Na 함량(含量)은 산성우처리(酸性雨處理)에 의해 크게 영향받지 않았다. 치환성(置換性) Al 함량(含量)은 처리산성우(處理酸性雨)의 pH 값이 낮을수록 현저히 증가(增加)하였다. 2. 토양(土壤)의 유효인산함량(有效燐酸含量)은 처리산성우(處理酸性雨)의 pH 값이 낮을수록 감소(減少)했으며, 처리전(處理前)에 비하여 묘포토양(苗圃土壤)에서는 증가(增加)한 반면 혼합토양(混合土壤)과 사질토양(砂質土壤)은 감소(減少)하였다. 3. 토양(土壤) sulfate 및 nitrate 함량(含量)은 pH 값이 낮을수록 높아졌으며, sulfate 함량(含量)만이 pH 간에 유의성(有意性)이 인정(認定)되었으며, 그 함량(含量)은 묘포토양(苗圃土壤), 혼합토양(混合土壤) 및 사질토양(砂質土壤)의 순(順)으로 증가(增加)하였다.