【摘要】 以中国科学院红壤生态实验站林草生态试验区阔叶林红壤为对象,通过土壤淋溶试验,模拟研究了不同氮输入量对南方红壤阳离子(Ca2+、Mg2+、K+、Na+、H+和A l3+)淋溶的影响。结果表明,无氮(0mgN/月.柱)、低氮(7.8 mg N/月.柱)、中氮(26 mgN/月.柱)和高氮(52 mg N/月.柱)输入处理下,土壤交换态盐基淋溶总量分别占土壤交换性盐基总量的13.6%,18.4%,27.7%,48.1%。不同的盐基离子对氮输入的反应不同,Ca2+和Mg2+淋溶量随氮输入量的增加而增加,对Na+和K+则无明显影响。土壤交换态离子中随淋洗液输出最多的为Ca2+(无氮、低氮、中氮和高氮输入处理的土壤交换态输出量占土壤交换态的比例分别为22.6%,31.4%46.7%,82.5%),其次为Na+(其比例分别为16.0%,10.7%,17.6%,26.3%),最少的为Mg2+(其比例分别为5.0%,6.9%,11.1%,16.9%),无土壤交换性K+输出。随氮输入的增加,土壤致酸离子H+和Al3+的淋溶量增加。大气氮沉降的增加,将加速南方红壤的养分淋失和相邻水体的酸化。更多还原

【Abstract】 In this study,a soil column leaching experiment was conducted to investigate the effects of simulated N deposition on cation(Ca2+,Mg2+,K+,Na+,H+ and Al3+)leaching from a broadleaf forest soil at the Red Soil Ecological Experiment Station,Jiangxi Province.Results showed that the percentages of total exchangeable base cations leached from the soil to total exchangeable base cations increased from 13.6% in the control treatment to 18.4%,27.7% and 48.1% in the 7.8,26 and 52 mg N/(mo·col) treatments respectively.Exchangeable base cations responded differently to N deposition.Ca2+ and Mg2+ leaching losses increased as N deposition increased,but N deposition rates had no effect on the leaching of K+ and Na+.The percentage of exchangeable Ca2+ leached from the columns increased from 22.6% in the control treatment to 31.4%,46.7% and 82.5% in the 7.8,26 and 52 mg N/(mo·col) treatments.Similarly the percentage of exchangeable Mg2+ leached from the columns increased from 5.0% in the control treatment to 16.9% in the 52 mg N/(mo·col) treatment.In contrast,the percentage of exchangeable Na+ leached from the four treatments was 16.0%,10.7%,17.6% and 26.3% in the 0,7.8,26 and 52mg N/(mo·col) treatments respectively.No exchangeable K+ was observed in the leachate of any treatment.The leaching of acidic ion of H+ and Al3+ increased as N inputs increased.The results from this study indicated that increased N deposition rates will increase soil nutrient losses and the acidity of neighboring water body in the red soil region of southern China.更多还原