Effect of Lime Materials Application on Reducing Injury of Simulated Acid Rain in Soybean

콩의 산성비 피해경감을 위한 석회물질의 시용효과

This experiment was conducted to find out the effects of lime materials application on reducing injury of simulated acid rain(SAR) in soybean grown in pot contained with sandy loam. Six treatments including control, slaked lime(SL), 1% and 2% lime water(LW) and composite treatments with SL+LW were applied. Slaked lime was applied to soil in pot before planting, and lime water was applied to leaves a day prior to the spray of SAR(pH 2.7) and normal rain(pH 6.0), and these were sprayed at 2-day intervals. Growth, yield and yield components, foliar injury rate, chrolophyll content and photosynthetic activity in leaves, content of mineral nutrients in plant and soil chemical properties were analyzed and investigated. These results obtained are summarized as follows : Seed yield of all lime treatment was reduced by SAR compared with control. But seed yield of all lime treatment was increased with treatment of lime material in soil and on leaves. After 15 and 45 times spray of SAR, all lime treatments were effective in injury reducing visible injury of leaves compared with none treatment. Chlorophyll content in leaves was highest in plants treated with slaked lime+ 1% lime water and photosynthetic activity was highest with treatment of slaked lime. Concentration of total nitrogen, phosphate, and sulfur in soybean plant were increased by the spray of SAR. Concentration of total nitrogen, potassium and calcium in soybean plant were increased with treatment of slaked lime into soil. By treatments of SAR, soil pH was decreased, and total nitrogen and sulfur concentration in soil were increased. However, available phosphate and exchangeable cations in soil such as calcium, magnesium and potassium were reduced. Soil pH, calcium and silicate concentration were increased with treatment of slaked lime into soil.

산성비에 의한 작물의 피해경감방안을 구명하고자 pot시험으로 사양토에 콩(단엽콩)을 공시작물로하여 석회물질을 토양(소석회), 엽면(석회유 1%, 석회유 2%), 토양 및 엽면(소석회+석회유 1%, 소석회+석회유 2%)에 처리하고, 인공산성비(pH 2.7)를 10mm씩 2일간격으로 50회 살포한 후 콩의 생육, 수량 및 수량구성요소, 가시적 엽피해율, 엽록소 함량, 광합성 능력, 식물체중 무기성분 함량, 시험후 토양의 이화학적 특성 등을 분석조사한 결과는 다음과 같다. 1. 인공산성비 45회 살포후 경장은 석회유 2%구에서, 엽수는 소석회+석회유 1%구에서 가장 컸으며, 엽폭, 경경, 개체당 분지수는 처리간에 유의성없이 비슷하였다. 인공산성비 살포에 의하여 전처리구에서 종실 수량이 감소하였으나, 석회물질의 처리구에서 종실 수량이 증가하였으나, 특히 소석회+석회유 1%구가 가장 좋았다. 2. 인공산성비 15 및 45회 살포후 엽피해율 경감효과는 석회물질의 시용이 효과적이었다. 3. 인공산성비 45회 살포후 엽록소 함량은 소석회+석회유 1%구에서 가장 높았으며, 인공산성비 30회 살포후 광합성 능력은 소석회구에서 가장 좋았다. 4. 인공산성비 살포로 식물체중 질소, 인산, 황 등의 함량이 증가되었으며, 소석회를 토양에 처리함으로써 식물체중 질소, 카리, 석회 등의 함량이 증가하는 경향이었다. 5. 인공산성비 살포로 토양의 pH는 낮아졌으나, 질소 및 황 함량은 증가되는 경향이었고, 인산, 석회, 카리, 고토등의 함량은 감소되는 경향이었다.