Abstract:
This study was conducted to determine copper and zinc accumulation in lettuce
planted in sida soil amended with lignite bottom ash. The copper and zinc
accumulation in sida soil, bottom ash, sida soil added with bottom ash, lettuce root and
lettuce leaf were investigated. Nitrogen, phosphorus and potassium in sida soil, in
bottom ash and in sida soil added with bottom ash, and the lettuce yield were also
investigated. Lettuce seed were cultured and grown in five ratios of sida soil added
with bottom ash. Lettuce was planted and grown under laboratory conditions. The
collected data were analyzed using one-way ANOVA and the mean comparison was
conducted using LSD.
Results indicated that mixed sample ratio 0.6:0.4 had the highest copper and zinc
accumulation (26.13±2.30 and 137.74±4.13 mg/kg). Copper and zinc accumulation in
mixed sample ratio showed significant difference as bottom ash ratio increased
(p<0.05). The highest copper and zinc accumulation was found at ratio of 0.6:0.4 in
lettuce root (21.46±5.90 mg/kg and 113.47±4.13 mg/kg), followed by lettuce leaf
(8.18±1.20 mg/kg and 32.94±7.34 mg/kg). The accumulation in root and leaf of lettuce
was significantly different as bottom ash ratio increased (p<0.05). The highest lettuce
yield was found at both ratio of 0.8:0.2 and 0.6:0.4 with 1.43±0.06 and 1.43±0.03
gm/plant, respectively. A significant difference in lettuce yield with the increase of
bottom ash ratio was observed (p<0.05).
The results suggest that lettuce leaf at all ratios are not harmful for consumers.
The lettuce leaf at all mixed sample ratios did not exceed the heavy metal
contamination according to the Criteria of Food and Drug Administration. However,
leachate generated, cultured lettuce in vegetable garden, and use of other crop types
still requires additional study for future use.