施用稻草对酸性红壤活性铝的动态影响  

Dynamic Effects of Rice Straw on Different Forms of Active Aluminum in Acidic Red Soil

作　　者：吕焕哲[1,2] 王凯荣[1] 谢小立[1] 陈安磊[1] 

机构地区：[1]中国科学院亚热带农业生态研究所,湖南长沙410125 [2]中国科学院研究生院,北京100039

出　　处：《土壤通报》2008年第2期321-324,共4页Chinese Journal of Soil Science

基　　金：CERN野外台站研究基金;中国科学院知识创新项目(KZCX3-SW-441)联合资助项目

摘　　要：酸性红壤区土壤活性铝含量的变化,对作物生长有重要影响。通过室内培养试验研究了施用不等量稻草对酸性红壤水溶性有机碳、pH值和土壤交换性铝和有机络合态铝的动态变化。结果表明,土壤水溶性有机碳在第一天达到最大值,之后开始下降直至趋于平衡。土壤pH值在前10天内快速提高,添加的稻草量越大,提高的幅度也越大,之后缓慢下降至第30天渐趋平衡;土壤交换性铝则是先降低,10天后逐渐增加至稳定状态。有机络合态铝在可溶性有机碳和有机酸等小分子化合物的联合作用下,先增加而后降低。在稻草分解的前10天,土壤水溶性碳、小分子化合物和土壤pH值对铝形态的影响均较大,而到实验后期,土壤pH值发挥着主导作用。Aluminum makes up 7% of the earth＇s crust and occurs in a number of forms in soil. It is harmless as oxides and aluminosilicates However Nevertheless, if the soil pH in 40% of the arable lands in the world is 〈5, Al will be solubilised into toxic forms, generally referred to Al^3＋, which is a primary factor limiting plant growth. A possible alternative to ameliorate Al toxicity is the application of rice straw. Hence, laboratory incubation studies were conducted to determine the dynamics effects of rice straw on different Al forms. The results revealed that Al forms, soil pH, and soluble carbon changed rapidly in 30 days, and the change correlated with the amount of rice straw addition. Soil pH increased rapidly in the first 10 days, and then decreased until the 30th day. The total soluble carbon was the highest on the first day after straw application, and then slightly decreased. As we all know soil pH negatively correlates with soil exchangeable Al, so exchangeable Al decreased in the first 10 days with the pH increasing, and then became stable. The curve of organically complexed Al increased to its peak on the 10th day, and then reached a balance level. Soil dissolved carbon, low- molecular-weight aliphatic carboxylic acids, and pH were responsible for the changes of aluminum forms in the first ten days, and then pH played more and more important role.

关 键 词：水溶性有机碳 土壤PH 土壤交换性铝 有机络合态铝 

分 类 号：S158.4[农业科学—土壤学]