摘要
对两种不同耕作年限红壤的磷吸附解吸特性及环境效应进行了研究,结果表明:两种不同耕作年限的红壤对磷的吸附量均随磷液浓度的增加而增加,且新开垦地土壤对磷的吸附速度高于多年耕作地土壤;土壤磷的解吸受土壤吸附磷量的制约,在土壤磷液浓度相等的条件下,土壤磷的吸附量越大则磷解吸量相应增加,而土壤磷最大吸附量越高,则磷的解吸量反而越少。Langmuir方程可以很好地拟合磷吸附过程。多年耕作地土壤磷吸附饱和度比环境敏感临界指标(25%)小1.5个百分点,表明经长期耕作的农田土壤磷已经接近流失的临界值,施磷肥要量出而入;而新开垦的耕地磷吸附饱和度仅为9.6%,为了达到高产目的仍需要多施磷肥。
The characteristics of phosphorus （P） sorption-desorption and its environmental impact were investigated in red soils （field with tillage practices for a long time and field with tillage practices for 2-3 years）. The results indicated that the two soils had strong capacity to adsorb phosphorus.This capacity with the concentration of phosphorus increased, field with tillage practices for a long time released more phosphorus than that of tillage practices for 2-3 years.The content of phosphorus desorption of two soils was enhanced with the increasing of phosphorus adsorption, in other words, release of phosphorus depended on phosphorus saturation degree. Phosphorus adsorption curves could be well described by Langmuir equation. Field with tillage practices for a long time had phosphorus saturation degree lower 1.5% than 25%, an environmentally sensitive threshold.field with tillage practices for a long time should be applied in accordance with the expected demand for phosphate fertilizer, field with tillage practices for 2-3 years had phosphorus saturation only 9.6%. In order to achieve high-yield,soil use more phosphorus fertilizer.
出处
《广东农业科学》
CAS
CSCD
2007年第11期85-87,共3页
Guangdong Agricultural Sciences
基金
江西省自然科学基金项目(0630103)
江西省教育厅项目([2007]346号)
关键词
红壤
磷吸附
磷解吸
磷饱和度
环境效应
red soil
phosphorus sorption
phosphorus desorption
phosphorus saturation
environmental impact
