Ling Da-Jiong, Zhang Jia-En, Ouyang Ying, Huang Qian-chun
Department of Resources and Environment, Agriculture College of Guangdong Ocean University, Zhanjiang City, Guangdong, China.
Arch Environ Contam Toxicol. 2007 Jan;52(1):16-21. doi: 10.1007/s00244-006-0004-8. Epub 2006 Nov 2.
Acid rain is a serious environmental problem in the world and is of a particular concern in southern China where most of the soils are acidic. This study investigated the dynamics of cations, phosphorus (P), and soil organic matter (SOM) in the Latosol (acidic red soil) from south China under the influences of simulated acid rain (SAR). Laboratory experiments were performed by leaching the soil columns with SAR at pH levels ranging from 2.5 to 7.0 over a 21-day experimental period. Results show that about 34, 46, 20, and 77% of the original exchangeable soil Ca(+2), Mg(+2), K(+), and Na(+), respectively, were leached out by the SAR at pH 2.5 after 21 days. Two distinct patterns of the available phosphorus (AP) concentrations were observed: one at pH< or =3.5 and the other at pH > or = 4.0. At pH< or =3.5, concentrations of the AP increased from the beginning of the experiments to day 5, then decreased from day 5 to 15, and finally increased from day 15 to the end of the experiments. At pH > or = 4.0, concentrations of the AP increased consecutively from the beginning of the experiments to day 10 and decreased from day 10 to the end of the experiments. Such a finding is useful for agricultural practices since soil P is one of the most important macronutrients for plant growth. In general, SOM content decreased with time as the Latosol was leached by the SAR at all pH levels. A maximum concentration of soil fulvic acid was found after 15 days of the experiments due to the degradation of the SOM. A multiple regression analysis showed that a very strong relationship was obtained between the soil AP and the other three parameters (i.e., pH, SOM, and sorption P).
酸雨是全球一个严重的环境问题，在中国南方尤其令人关注，那里大部分土壤呈酸性。本研究调查了模拟酸雨（SAR）影响下中国南方砖红壤（酸性红壤）中阳离子、磷（P）和土壤有机质（SOM）的动态变化。通过在21天的实验期内用pH值范围为2.5至7.0的SAR淋洗土柱进行实验室实验。结果表明，21天后，pH值为2.5的SAR分别淋洗出了约34%、46%、20%和77%的原始土壤可交换钙（Ca(+2)）、镁（Mg(+2)）、钾（K(+)）和钠（Na(+)）。观察到有效磷（AP）浓度有两种不同模式：一种在pH≤3.5时，另一种在pH≥4.0时。在pH≤3.5时，AP浓度从实验开始到第5天增加，然后从第5天到第15天下降，最后从第15天到实验结束时增加。在pH≥4.0时，AP浓度从实验开始到第10天连续增加，并从第10天到实验结束时下降。这一发现对农业实践很有用，因为土壤磷是植物生长最重要的大量营养素之一。总体而言, 随着砖红壤在所有pH水平下被SAR淋洗，SOM含量随时间下降。由于SOM的降解，在实验15天后发现了土壤富里酸的最大浓度。多元回归分析表明，土壤AP与其他三个参数（即pH、SOM和吸附磷）之间存在非常强的关系。
