碳酸钙和硼对棕红壤油菜锰毒缓解作用

对已酸化的棕红壤进行的油菜锰毒缓解研究表明， 施用碳酸钙在提高土壤ｐ Ｈ 和降低土壤交换性锰的基础上， 改善了土壤营养状况， 其中施用０ ． ５ ％ 碳酸钙处理的效果最好， 在这一碳酸钙水平下，土壤硼处于较高的活性， 土壤速效磷钾被油菜幼苗充分利用， 油菜幼苗对营养元素具有最大吸收量，使植株生物学产量达到最大值。酸化的棕红壤只需施用０ ． ５ ％ 的碳酸钙， 其土壤酸碱度便可恢复到正常水平， 如施用更多的碳酸钙， 会造成土壤营养再度失调， 油菜幼苗的生物学产量下降。在施用碳酸钙基础上配施硼素， 可使油菜生物学产量进一步提高， 相应的土壤环境得到更好的改善， 施硼可以降低锰毒植株磷的浓缩效应和提高营养元素的利用效率。因此， 碳酸钙－ 硼配施是缓解棕红壤油菜锰毒的一项重要措施。

The Detoxification ofCalcium Carbonate and Boron to Manganese Toxicity of Rape Crop in Acid Brown Red Soil.

The study on the detoxification to manganese toxicity of rape crop grown on an acid brown soil has been conducted. The application of calcium carbonate could raise pH of the tested soil and decrease its exchangeable Mn. Hence,this practice improved the nutrition condition of the soil. Among the treatments of applying CaCO 3,0.5% CaCO 3 had the best effect,for example,availability of soil boron was high and soil available phosphorous or potassium were used more. It made a maximum absorption of nutrients by the crop,the biological weight of rape seedling was the highest. In the application of 0.5% CaCO 3 to the brown red soil,its acidity would return to normal,but when it was added more CaCO 3 than 0.5% level,its nutrition dislocated and the biological yield of rape seedling decreased again. The application of CaCO 3 with boron improved the nutrient environment more effectively,and made the seedling yield of rape enhance further. Boron would decrease the enriched effect of nutrient in rape plant in the soil of excessive manganese and improve the utilization ratio of nutrient elements. Therefore, the application of CaCO 3 with B is an important role in the detoxification of manganese toxicity of rape crop in the brown red soil.