This study aimed to investigate the effects of soil amendment (heat-expanded clay and active carbon) and planting of Dendranthema zawadskii var. latilobum on the remediation of salt-affected soil and the plant growth under high calcium chloride (CaCl2) concentration. The experimental group comprised treatments including Non treatment (Cont.), heat-expanded clay (H), active carbon (AC), planting (P), heat-expanded clay+planting (H+P), active carbon+planting (AC+P). A 200 mL solution of CaCl2 at a concentration of 10 g·L-1 was applied as irrigation once every 2 weeks. Compared to the Cont., the incorporation of the ‘heat-expanded clay’ amendment decreased electrical conductivity of the soil leachate and cation exchange capacity, whereas the growth of Dendranthema zawadskii var. latilobum was relatively increased. These results suggest that the combination of ‘heat-expanded clay’ amendment and planting will mitigate negative effect of de-icing salts and improve plant growth in salt-contaminated roadside soils.

This study was conducted to investigate the growth of Dendranthema zawadskii in damaged soils when they are treated with improvement agents. The treatments consisted of a control (unamended field soil) and the application of a loess ball of 1 cm to the field soil. According to the degree of damage the de-icing agent had caused, the soils were divided into 3 areas (based on the yellowing of Pinus densiflora for. multicaulis in soil surveys): H (high saline), M (medium saline), and L (low saline). A total of six treatments were performed: D. zawadskiia plant without soil amendment (H; high saline soil, M; medium saline soil, L; low saline soil), and a D. zawadskiia plant with loess ball on the soil surface (H.L; high saline soil with loess ball, M.L; medium saline soil with loess ball, L.L; low saline soil with loess ball). The results showed that D. zawadskiia growth went from highest to lowest in the order: M.L > L.L > M > L > H.L > H. Plant growth results showed that soils treated with soil amendments (loess ball) were better for D. zawadskii growth than untreated soils.

화산회토양 감자 연작지 토양 pH 수준별로 고토석회, 유황, 황산칼륨, 패화석, 규산질비료, 석회질소, 유안비료를 이용하여 감자 더뎅이병 발생을 경감시키고 토양건전성을 유지하는데 적절한 대체농자재를 선발하고자 수행하였다. 토양 pH가 낮은 황산칼륨 처리구(24 kg/10a)에서는 더뎅이병 발병률이 84.4%, 발병도가 28.4%로 가장 낮았다. 방제효과는 12.3%, 상품율은 93.2%로 다른 처리구와 비교할 때 가장 높게 나타났다. 석회질소 처리구(60 kg/10a)가 발병도 38.3%로 낮았고 방제효과 23.8%, 상품율 66.3%로 높았다. 토양 pH가 높은 시험구 중 더뎅이병 발병률은 석회질소 처리구(60 kg/10a)가 38.3%로 가장 낮았고 유안 처리구(48 kg/10a)는 62.6%로 높았다. 더뎅이병 방제효과는 석회질소 처리구(60 kg/10a)에서 23.8%로 유황 처리구의 6.1% 보다 4배 이상, 상품률은 66.3%로 가장 높게 나타났다. 감자 더뎅이병 병원균 Streptomyces acidiscabies과 Streptomyces scabiei를 석회질소 2.5, 5 g/L, 10 g/L에 접종시 생장량은 다른 토양개량제 보다 상대적으로 억제되었다. 결론적으로 감자 파종 전에 토양 pH가 5 이하이면 황산칼륨을, 6 이상이면 석회질소를 시비하면 더뎅이병 발생을 경감시킬 수 있을 것으로 보인다.

Difference in immobilization effect of heavy metal-contaminated soil between two different amendment methods was evaluated; 1) both of steel slag (i.e., consisted in solid phase) and soluble phosphate (i.e., consisted in liquid phase) were simultaneously applied to contaminated soil (i.e., simultaneous amendment methods) and 2) soluble phosphate and steel slag was applied sequentially to the contaminated soil (i.e., sequentially amendment methods). The application rate of stabilizers to soils was determinated based on weight/weight ratio of 5% for steel slag and PO4/Pb molar ratio of 2.0 for phosphates, respectively. To identify difference of immobilization effect to test soil, three different soluble phosphates, such as Na2HPO4·12H2O, Ca(H2PO4)2·H2O and (NH4)2HPO4 were used. The sequential amendment was 6 ~ 27% more effective than the simultaneous amendment in terms of the immobilization efficiency for Pb, Cu, and Cd in the contaminated soil. There was little difference in case of Zn. Among the three phosphates tested, (NH4)2HPO4 was clearly the most effective. Residual form of heavy metals concentration in sequentially methods is higher than those in simultaneously methods. At the same time, more exchangeable and carbonate-bound forms of heavy metals in simultaneously methods were observed than in sequentially case. These result implies that the sequential amendment method was more effective than the simultaneous amendment method in terms of heavy metal immobilization in the contaminated soil.