Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/27678
標題: 質材的施用對強酸性土壤剖面陽離子及鋅污染之改善研究
Research of amendment application on the amelioration of profile cations and zinc pollution in a strongly acidic soil
作者: 林勇偉
Lin, Yong-wei
關鍵字: 連續萃取法;sequential extraction;有效性;陰離子;availability;anion
出版社: 土壤環境科學系
摘要: 
Strong acid soil (pH < 5.5) is one of the major arable soils in Taiwan. Due to aluminium phytotoxic and calcium deficiency, the growth of the crop root is limited, and the quality and the yield of crops are often influenced in the acid soils. Potassium chloride is the most frequently used potassium fertilizier, however, it might cause the release of soil exchangeable aluminium and an increase in aluminium concentration in soil solution. In the other case, when is soil was polluted by heavy metals, it may cause not only an unfavorable influence to crop, but also give a detrimental effect to human health. Limed the pollued soils with various anions, the adsorption and mobility of heavy metal in the soil profile may be influenced which may result in a decrease in the performance of the limings. This study includes two tests, the first test is to investigate the influences of amendment addition on the acidity, the availabilities of cations, and particularly the changes of exchangeable Al in a KCl treated soil. Our purpose is to establish a suitable practice for both the amelioration of soil acidity and the management of K fertilizer. The second test is to evaluate the effects of Ca amendment on the mobility cation and the amelioration of zinc polluted profile soil.
In the study, Huan-Si strong acid soil was selected to conduct a column leaching experiment. The column was packed in a way similar to the Huan-Si soil profile soil. In the test one, 200 mg K kg-1 potassium chloride was mixed with the top 10 cm soil in each column and incubated for 7 days, then different amendments were mixed with 0 ~ 20 cm soil, the treatments including lime, gypsum, and animal compost. A total of 2500 mm deionized water, which equals the amount of one-year rainfall in Taiwan, were added for 120 days. After the leaching experiment and standing for 7 days, some properties of the soil were determined, including pH, exchangeable Ca, Mg, Na, and Al, solution K, exchangeable K, and non- exchangeable K. In the test two, 650 mg Kg-1 ZnCl2 was mixed with the top 5 cm soil in each column, and was incubated under drying-wetting cycles for three weeks. Then, different amendments were added with mixing, the treatments including lime, gypsum, and calcium citrate. A total of 1250 mm deionized water, which equals the amount of half-year rainfall in Taiwan, were added for 60 days. After the leaching experiment, a portion of soil properties were determined, including pH, exchangeable Ca, Mg, K, Na, and Al, HCl -extraction Zn, total Zn, and the forms of Zn were determined by the sequential extraction method.
The results of test one showed that an increase in the content of exchangeable Al in the subsoil and a decrease in soil pH were observed while soil was treated with KCl. The results indicate that KCl may lead to some detrimental effects for KCl treated soils such as Al toxicity. The lime addition reduced the content of exchangeable Al down to 40 cm depth and increased the content of exchangeable Ca down to the 60 cm depth of the soil profile. Aminal compost treatment also reduced the contents of exchangeable Al down to the 70 cm depth of the soil profile, especially in the soil profile of 0 ~ 30 cm. The results of test two showed that the application of lime and calcium citrate could increase significantly soil pH. Besides, this application could reduce mobility and availability of zinc in soil. Gypsum and calcium citrate could barely elevate soil pH which may keep zinc mobile in the soil and may be easily leached out of the top soil by added Ca. Treatment with Ca nitrate increased significantly in the mobility of znic in soil profile. However, this treatment may simultaneously decrease the exchangeable Mg in the soil profile. As a result, the crop growth could be inhibited due to the lack of Mg.

強酸性土壤(pH<5.5)為台灣主要耕地土壤之一,惟其剖面土壤鋁毒害及鈣缺乏,常常限制作物根系的生長,進而影響作物品質及產量。氯化鉀為最常用之鉀肥,惟可能導致土壤交換性鋁之釋出而增加土壤溶液中的鋁濃度。另土壤受重金屬污染,不但對作物生長產生不利之影響,且可能危害人體健康。於污染土壤施用含不同陰離子之石灰質材,對土壤剖面重金屬的吸附和移動性可能不同,進而影響改良的效果。本研究分成兩個試驗,試驗一之目的乃在探討改良質材的施用對施用氯化鉀之強酸性土壤剖面酸性及陽離子有效性,尤其是交換性鋁的消長,以作為研擬改良土壤酸度及鉀肥管理的參考依據。試驗二之目的乃在評估不同含鈣質材之施用,對於鋅污染土壤剖面中陽離子的運移及鋅污染改良的效應。
本研究係以管柱分層方式分別模擬強酸性之關西土壤剖面。試驗一乃先於表土0 ~ 10 cm中添加200 mg kg-1的氯化鉀,待培育7天後再分別於土壤0 ~ 20cm施用石灰、石膏及禽畜糞堆肥,並模擬台灣年雨量約2500 mm,以去離子水淋洗120天,期間測定淋洗液之pH、EC、鈣、鎂、鉀及鈉濃度。待淋洗完成後並靜置7天後,將土壤分層取出,測定各處理各土層土壤之pH、交換性鈣、鎂、鈉、鋁及各型態鉀。試驗二之鋅污染改良試驗中,先將表土0 ~ 5 cm土壤添加650 mg kg-1的氯化鋅,乾濕培育三週後再分別施用石灰、石膏、硝酸鈣及檸檬酸鈣等質材,再以去離子水模擬降雨淋洗土柱,期間測定淋洗液之pH、EC、鈣、鎂、鉀、鈉及鋅濃度,待淋洗完成後,取出各處理各土層土壤,測定土壤pH、交換性鈣、鎂、鉀、鈉、鋁、鹽酸萃出性鋅及總鋅量,並以專一萃取劑連續萃取法測定各型態鋅的含量。
試驗一之結果顯示,於強酸性土壤施用氯化鉀將增加底層土壤之交換性鋁含量,並降低其剖面土壤pH,而加重剖面酸性及交換性鋁含量潛在問題。石灰之施用可降低0 ~ 40公分土壤之交換性鋁含量,並增進0 ~ 60 公分土層土壤之交換性鈣含量。石膏之施用對土壤pH的提昇效應不彰,但能顯著降低整個剖面土壤交換性鋁含量及增進交換性鈣含量。石灰和石膏之處理會降低交換性鎂及鉀之含量,故欲施用此兩種質材來改善強酸性土壤時,宜顧及鎂肥及鉀肥之補充。禽畜糞堆肥處理亦可降低整個剖面土壤之交換性鋁含量,尤其以30公分內土壤最為顯著。由於禽畜糞堆肥本身亦含有鈣、鎂、鉀及鈉,施用禽畜糞堆肥故能增進整個剖面土壤之交換性鈣、鎂、鉀及鈉含量。
試驗二之結果顯示,關西土壤遭受鋅之污染,由於土壤pH低,使關西土壤吸附鋅的能力不高,然而若被土壤吸附後,鋅則難以由土壤中移出。關西鋅污染有較大比例的交換態,而此型態為植物可直接利用之部份,故可能有危害作物生長之顧慮。石灰及檸檬酸鈣之施用,可顯著提昇土壤pH,並可減少土壤中交換態之比例,而轉換成作物較難易用的鐵、錳氧化物型態。石膏及硝酸鈣之施用,對土壤pH提昇效果不彰,但表層土壤存留的鋅,以殘留態佔大部分。在整體土壤剖面pH提昇及交換性鋁含量的降低,以石灰和檸檬酸鈣之處理較顯著,但土壤pH提昇使鋅被固持於表層土壤,無法移至較下層土壤而達到降低表土鋅過量的期望。另石灰和檸檬酸鈣的施用易造成表土交換性鎂的下降,欲使用石灰或檸檬酸鈣來改良強酸性土壤剖面酸性時,宜有適當的鎂之補充,以避免因鎂之缺乏而抑制作物之生長。石膏和硝酸鈣對強酸性土壤pH之提昇效果不彰,故能有效移除表層土壤鋅之累積,尤其又以硝酸鈣處理,在影響鋅運移效果的評比中為最佳,唯硝酸鈣處理會使整層剖面土壤交換性鎂含量降低,易造成鎂之缺乏而抑制作物之生長。
URI: http://hdl.handle.net/11455/27678
Appears in Collections:土壤環境科學系

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