过碳酰胺施用对中国南方六种土壤pH及活性铝短期变化的影响

为了研究施用过碳酰胺后中国南方6个酸性土壤pH值及活性Al的短期变化，进行了实验室模拟土培试验．结果表明：对6种酸性土壤施用不同浓度过碳酰胺，其pH值在短期内都随着施入过碳酰胺浓度的增大而急剧上升，交换性铝含量随着施用过碳酰胺浓度的增大而急剧下降；施用过碳酰胺后，土壤pH值上升的现象是短期的，pH值达到最大值后缓慢下降，而土壤中铝元素的有效性与土壤pH的变化趋势呈显著负相关；短期内，经过碳酰胺处理的玉米幼苗主根明显缩短，侧根生长受到抑制，并且其玉米铝毒明显重于不经过碳酰胺处理的玉米，被玉米吸收的铝主要分布在玉米的地下部分，只有较少的铝被转移到地上部分．

Effects of Applications of Percarbamide on Short-term Changes of Soils pH and Active Al in Six Soils in Southern China

Percarbamide is an important chemical product and a new fertilizer. It is widely used in foreign, but just beginning in China. Effects of applications of Percarbamide on short-term changes of Soils pH and active Al in six soils in southern China were studied with method of laboratory simulated soil cultivate tests. The results indicated that ： at 25℃, the changes of pH in acidic soils increased quickly, but soil exchangeable Al decreased, with the increasing concentrations of applied Percarbamide; The increase of soil pH was short-term, with a subsequently slow drop after reached their maximum, and there was a obviously negative relationship between soil exchangeable AI and soil pH; Mayor roots of maize were shorten obviously, and the growth of side roots were inhibited, moreover, the Al toxicity of maize with Percarbamide were more serious than that without Percarbamide, and majority of Al absorbed by maize were largely in roots, minority were in stems and in leaves.