施用除草劑達有龍、理有龍及愛速隆對土壤釋放溫室氣體之影響
Effect of application of herbicides diuron, liuron and isouron on the release of greenhouse gases from soil
顏瑞泓、林建彰、王一雄
國立台灣大學農業化學系
Abstract
The Effect of application the herbicides diuron, liuron and isouron on the release of carbon dioxide, methane and nitrous oxide in the soil under different temperatures and moisture content was performed with Miao-Li loam. Different concentrations of herbicide were spiked to the soil individually for incubating in two temperatures (20 and 30℃) and two moisture contents (field capacity and flooded). Gas chromatography was used to detect the release of these three gases from soil after different incubation times. Concentration seemed no significant effect on the release of carbon dioxide and nitrous oxide. But higher concentration of herbicide showed higher release of methane from soil. The higher the temperature treated, the more the carbon dioxide release, but in the opposite hand, the higher the temperature treated, the less the nitrous oxide release. There is no significant effect between temperature and release of methane. No methane release from soil was found at the moisture content of field capacity.
Key words: Carbon dioxide, Diuron, Isouron, Linuron, Methane, Nitrous oxide
摘要
本文在探討三種尿素系除草劑達有龍 (Diuron)、理有龍 (Linuron) 及愛速隆 (Isouron) 的施用對土壤釋放二氧化碳 (CO2)、甲烷 (CH4) 和氧化亞氮 (N2O) 三種氣體之影響。實驗土壤為採自苗栗造橋番子坡系之水田土壤，分別以0、1、10、 100 ��g/g soil 四種不同施藥濃度，在20及30℃二種溫度條件，田間容水量 (-1/3 bar) 及浸水狀況 (水/土壤=2/1(v/w)) 二種水分狀況下進行培育。在不同的培育時間下採樣並分析三種氣體的釋放量，以了解三種尿素系除草劑之施用對土壤釋放溫室效應氣體之影響。實驗結果顯示：三種除草劑的種類及施用量多寡對二氧化碳及氧化亞氮釋放量並無顯著影響，但是除草劑施用量增加則對甲烷的釋放有促進的效果。在較高的實驗溫度下二氧化碳的釋放量有增加趨勢，但氧化亞氮則反而減少，而甲烷則較不受溫度的影響。而土壤中水分含量則對甲烷的釋放有較大的影響，在田間容水量下甲烷幾乎不產生。由上述結果發現三種除草劑對土壤釋放溫室效應氣體之影響，不如水分和溫度這二種環境因子。
關鍵詞: 二氧化碳、甲烷、理有龍、氧化亞氮、達有龍、愛速隆