| 长期施肥对旱地红壤及作物中砷累积的影响 |
| 摘要点击 2363 全文点击 971 投稿时间：2017-07-05 修订日期：2017-09-15 |
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| 中文关键词 砷累积 同步辐射 土壤 长期定位施肥试验 矿物 有机肥 |
| 英文关键词 As accumulation synchrotron radiation techniques soil long-term fertilization experiment minerals organic fertilizers |
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| 中文摘要 |
| 以湖南祁阳农田生态系统国家野外试验站的土壤为研究对象，分析了长期施肥措施对砷在土壤及作物籽粒和秸秆中累积的影响.供试土壤选择了4个不同施肥处理：不施肥（CK）、单施化肥（NPK）、单施有机肥（M）和化肥有机肥配施（NPKM）.结果表明，与不施肥相比，长期（26 a）施肥措施（NPK、M和NPKM）均显著增加了红壤中总砷（As）和有效态砷含量，其中，NPK处理的红壤中砷含量超过国家标准值（40 mg·kg-1）.长期施肥处理对非专性吸附态As影响最大，其次为残渣态As，晶型氧化物结合态As，但对专性吸附态As和无定型铁铝氧化物结合态As的影响较小.与CK、NPK、M处理相比，NPKM处理能显著降低土壤中As（Ⅲ）和As（Ⅴ）含量.此外，施用有机肥（猪粪）会导致玉米籽粒和秸秆中As的累积，而不会导致小麦籽粒和秸秆中的As累积.同步辐射红外显微成像和微束X射线荧光谱图显示了红壤样品中As、黏土矿物和有机官能团在微空间尺度上的高度异质性特征，表明As的有效性主要受铁氧化物和羟基碳的影响. |
| 英文摘要 |
| To investigate the effects of different long-term fertilization treatments on arsenic (As) accumulation in upland red earth and the crops growing on it, different fertilization treatments, including no fertilization (CK), fertilization with chemical fertilizers containing nitrogen, phosphorus and potassium (NPK), fertilization with swine manure (M), and fertilization with chemical fertilizers plus manure (NPKM), in a long-term fertilization site located in Qiyang County, Hunan Province, were selected.. The results showed that after 26 years of fertilization, both the total and available As concentrations in the soils were significantly improved in the fertilized soils (i.e., NPK, M, and NPKM) when compared to the CK soil. Meanwhile, NPK treatment had the highest As concentration (44.68 mg·kg-1), which was higher than the national standard value (40 mg·kg-1) in acidic soils. Fertilization practices had the biggest impacts on the non-specifically-absorbed As, followed by the residual As, and the well-crystallized hydrous oxides of Fe and Al absorbed As, but minor impacts on the amorphous and poorly-crystalline hydrous oxides of Fe and Al-absorbed As, and the specifically absorbed As. Furthermore, NPKM treatment significantly decreased the concentrations of As(Ⅲ) and As(Ⅴ) in the soils, when compared to the other treatments. Also, M treatment could cause the accumulation of As in the grains and straws in corn. In contrast, M treatment could not cause the accumulation of As in the grains and straws in wheat. Furthermore, correlative synchrotron-radiation-based FTIR and micro X-ray fluorescence spectromicroscopic analysis showed that As had a similar distribution pattern with clay -OH and C-OH. |
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