施用石灰與堆肥對水稻及青梗白菜中銅和鋅相互作用之影響

Abstract

化學固定法可用於整治銅鋅汙染土壤，進而降低作物體中銅和鋅的含量。然而，前人研究多著重於尋找有效改良劑以降低作物體中銅和鋅的濃度，並未探討施用改良劑後，作物體中銅和鋅之相互作用。本研究目的為瞭解施用石灰與堆肥後，作物體與土壤中銅和鋅之相互作用，並以三種萃取劑預測作物體中銅和鋅的濃度。本研究選用水稻臺南 11 號（Oryza sativa L. Tainan 11）及青梗白菜Brassica chinensis L. cv. Ching-Geeng）兩種作物，種植於國立臺灣大學人工氣候實驗室。土壤添加三種銅濃度分別為 0、75 與 150 mg/kg，添加三種鋅濃度分別為 0、200 與 400 mg/kg，添加三種改良劑分別為未施用、施用石灰（調整 pH 至 6.8）與施用堆肥（60 ton/ha ），所有處理均施用化學肥料，並進行四重複。 研究結果顯示，未施用改良劑與施用石灰下，銅和鋅的相互作用對穀粒產量無影響。然而施用堆肥下，銅和鋅的相互作用對穀粒產量有顯著影響，且混合添加銅和鋅會使穀粒產量下降。銅和鋅的相互作用影響水稻各部位中銅和鋅的程度為：糙米 > 地上部 ≧ 稻根。不管有無施用石灰或堆肥，添加銅濃度 75 或 150 mg/kg 的土壤，再添加鋅 400 mg/kg，會促進糙米吸收銅。添加鋅濃度 200或 400 mg/kg的土壤，再添加銅 75 或 150 mg/kg，大致上不會促進糙米吸收鋅。所以添加鋅對糙米吸收銅的影響較大，添加銅對糙米吸收鋅的影響較小。 未施用改良劑下，銅和鋅的相互作用會影響青梗白菜的重量，混合添加銅和鋅會使青梗白菜重量降低。施用石灰與堆肥後，添加銅或鋅則對青梗白菜重量無影響。未施用改良劑下，添加銅濃度 75 mg/kg或 150 mg/kg 的土壤，再添加鋅200 或 400 mg/kg，會抑制青梗白菜吸收銅。不管有無施用石灰或堆肥，添加鋅濃度0、200 或 400 mg/kg 的土壤，再添加銅 75 或 150 mg/kg，不會促進青梗白菜吸收鋅。所以添加鋅會抑制青梗白菜吸收銅，添加銅不會影響青梗白菜吸收鋅。 大致上，不管有無施用改良劑，添加銅並不會促進或抑制 0.05 M EDTA 與 0.005 M DTPA 可萃取鋅濃度，反之亦然。未施用改良劑下，添加鋅會促進 0.01 M CaCl2 可萃取銅濃度，添加銅也會促進 0.01 M CaCl2 可萃取鋅濃度。施用石灰與堆肥後，添加鋅或銅則不會促進 0.01 M CaCl2可萃取銅或鋅濃度。 不管有無施用改良劑，0.05 M EDTA 及 0.005 M DTPA可萃取銅濃度可預測糙米及青梗白菜中銅的濃度。未施用改良劑下，0.05 M EDTA、0.005 M DTPA 及 0.01 M CaCl2 可萃取鋅濃度可預測糙米中鋅的濃度。不管有無施用改良劑，0.05 M EDTA、0.005 M DTPA 及 0.01 M CaCl2 可萃取鋅可預測梗白菜中鋅的濃度。

Chemical stabilization have been used to remediate copper (Cu) and zinc (Zn) contaminated soil for the purpose of reducing the Cu and Zn concentration of crops. However, previous studies emphasized on finding efficient amendments to reduce Cu and Zn concentration of crops, few of them investigated Cu-Zn interaction of crops and soil after applying lime or compost. The objective of this research aims to understand the Cu-Zn interaction of crops and soil after applying lime or compost, as well as predicting Cu and Zn concentration of crops by using three extractants. Rice (Oryza sativa L. Tainan 11) and Bok Coy (Brassica chinensis L. cv. Ching-Geeng) were chosen. Three spiked Cu concentration are 0 mg/kg, 75 mg/kg, and 150 mg/kg; three spiked Zn concentration are 0 mg/kg, 200 mg/kg, and 400 mg/kg; three amendments are no amendment (NA), lime, and compost. Chemical fertilizer was applied to every treatment, and conducted in four replicates. Results indicated that in NA and lime treatment, grain yield was not affected by Cu-Zn interaction. While under compost treatment, grain yield was significantly affected by Cu-Zn interaction, and grain yield was reduced markedly when soil was mixed with the combination of Cu and Zn. The effect of Cu-Zn interaction on Cu and Zn concentration in different parts of rice are as follows: brown rice > shoot ≒ root. Whether amendments were applied or not, adding Zn 400 mg/kg to soil spiked with Cu 75 or 150 mg/kg may stimulate brown rice to uptake Cu. Application of Cu 75 or 150 mg/kg to soil spiked with Zn 200 or 400 mg/kg doesn’t stimulate brown rice to uptake Zn. Therefore, the effect of Zn addition on brown rice to uptake Cu is stronger than Cu addition on brown rice to uptake Zn. In NA treatment, the weight of Bok Coy was affected by Cu-Zn interaction, and its weight was decreased after using combined Cu and Zn treatment. After applying lime or compost, Zn addition or Cu addition had no effect on Bok Coy’s weight. In NA treatment, adding Zn 200 mg/kg or 400 mg/kg to soil spiked with Cu 75 mg/kg or 150 mg/kg inhibited Bok Coy to uptake Cu, while the situation didn’t occur after applying lime or compost. With or without applying lime or compost, adding Cu 75 mg/kg or 150 mg/kg to soil spiked with Zn 0 mg/kg, Zn 200 mg/kg or Zn 400 mg/kg didn’t stimulate Bok Coy to uptake Zn. To sum up, Zn addition can inhibit Bok Coy to uptake Cu; Cu addition can’t affect Bok Coy to uptake Zn. In general, whether amendments were applied or not, 0.05 M EDTA and 0.005 M DTPA extractable Zn concentration wasn’t stimulated or inhibited by Cu addition, and vice versa. In NA treatment, Zn addition stimulates 0.01 M CaCl2 extractable Cu concentration, and vice versa. After applying lime and compost, Zn addition or Cu addition doesn’t stimulate 0.01 M CaCl2 extractable Cu and Zn concentration. Whether amendments were applied or not, 0.05 M EDTA, 0.005 M DTPA and 0.01 M CaCl2 extractable Cu concentration can be used to predict Cu concentration of brown rice and Bok Coy. In NA treatment, 0.05 M EDTA, 0.005 M DTPA and 0.01 M CaCl2 extractable Zn concentration can be used to predict Zn concentration of Brown rice. Whether amendments were applied or not, 0.05 M EDTA, 0.005 M DTPA and 0.01 M CaCl2 extractable Cu concentration can be used to predict Cu concentration of brown rice and Bok Coy. In NA treatment, 0.05 M EDTA, 0.005 M DTPA and 0.01 M CaCl2 extractable Zn concentration can be used to predict Zn concentration of Brown rice. Whether amendments were applied or not, 0.05 M EDTA, 0.005 M DTPA and 0.01 M CaCl2 extractable Zn concentration can be used to predict Zn concentration of Bok Coy.