Effects of copper concentration on methane emission from rice soils

详细信息    查看全文

• 作者：Jiao ; Yan ; Huang ; Yao ; Zong ; Lianggang ; Zheng ; Xunhua ; Sass ; Ronald L.
• 关键词：CH₄ emission ; Copper concentration ; Organic matter ; Pot experiment ; Soil DOC
• 刊名：Chemosphere
• 出版年：2005
• 出版时间：January, 2005
• 年：2005
• 卷：58
• 期：2
• 页码：185-193
• 全文大小：286 K

文摘

Outdoor pot experiments with various paddy soils representing five soil types were conducted at Nanjing Agricultural University during the 2000 and 2001 rice-growing seasons. Eighteen soils and ten out of the eighteen soils were involved in the 2000 and the 2001 experiment, respectively. Two treatments were designed as mineral fertilization (MF) and mineral fertilizer+wheat straw incorporation (MF+WS) for the 2001 experiment. Seasonal average rate of CH₄ emission from different soils ranged from 1.96 to 11.06 mgm⁻²h⁻¹ in the 2000 experiment, and from 0.89 to 5.92 mgm⁻²h⁻¹ for the MF treatment in the 2001 experiment, respectively. Incorporation of wheat straw enhanced considerably CH₄ emission with an average increment of 7.09 mgm⁻²h⁻¹. CH₄ emissions from the two-year experiment were negatively correlated to soil available and total copper concentration. A further investigation showed that CH₄ emission from the MF treatment was positively related to the dissolved organic carbon (DOC) in the soil (r=0.904, p<0.001), and that the DOC was negatively correlated to the concentrations of available copper (r=−0.844, p<0.01) and total copper (r=−0.833, p<0.01), respectively. Nevertheless, the incorporation of wheat straw did not enhance the soil DOC, and the relationship between CH₄ emission and soil DOC was not statistically significant (r=0.470, p<0.20). It was concluded that higher concentration of copper in the soils resulted in lower soil DOC and thus reduced CH₄ emission when there was no additional organic matter input. Incorporation of wheat straw did not affect soil DOC and available copper concentration but enhanced CH₄ emission.