坡耕地反坡水平阶对土壤水N、P垂直再分配的影响

 采用野外监测和室内实验分析相结合的方法,对昆明市松华坝水库水源区坡耕地反坡水平阶土壤水N、P垂直再分配进行研究,结果表明:1)土壤水总氮TN、氨态氮NH+4+-N、硝态氮NO3--N和总磷TP在20～40cm土层自然坡面和反坡水平阶2种处理差异性均显著,40～60 cm土层TN和NH+4+-N浓度和土壤TN质量分数相关系数为0.94(P<0.05)和0.97(P<0.01),土壤水TP浓度分别和土壤TP、AP质量分数相关系数为0.90(P<0.05)和0.98(P<0.01);40～60cm土层土壤水TN浓度和土壤TN质量分数相关系数为0.92(P<0.05),土壤水TP浓度和土壤AP质量分数相关系数为0.96(P<0.01);60～80cm土层土壤水NO3--N浓度分别和土壤TN、AN质量分数相关系数为0.90(P<0.05)和0.92(P<0.05),土壤水TP浓度和土壤AP质量分数相关系数为0.93(P<0.05);80～100cm土层土壤水NO3--N浓度和土壤AN质量分数相关系数为0.94(P<0.05);在0～100cm土层,反坡水平阶处理能有效地将坡耕地地表径流转化为土内径流,造成土壤水N、P质量分数不同程度的增高趋势;土壤水N、P在土壤剖面的运动是引起土壤N、P累积的动力。

Effect of horizontal stage on vertical redistribution of the soil water N and P Oil the sloping land

Combined field observation and laboratory experiment,the Nitrogen and Phosphorus in the soil water of horizontal stage in water source area of Songhuaba reservoir in Kunming were analyzed.The results indicated that TN,NH＋4-N,NO-3-N and TP had significant difference in the soil water of two treatments in soil layer from 20 cm to 40 cm,TN and NH＋4-N had significant difference from 40 cm to 60 cm.The four nutrient mentioned of soil water hadn＇t significant difference in two treatments,but hadn＇t significant difference from 60 cm to 100 cm.In soil layer from 20 cm to 40 cm,the correlation coefficients of TN,NH＋4-N concentration of soil water and TN content of soil were 0.94（P0.05） and 0.97（P0.01）,and the correlation coefficients of TP concentration of soil water and TP,AP content of soil were 0.90（P0.05） and 0.98（P0.01）.The correlation coefficient of TN concentration of soil water and TN content of soil was 0.92（P0.05）,and the correlation coefficient of TP concentration of soil water and AP content of soil was 0.96（P0.01） in soil layer from 40 cm to 60 cm.The correlation coefficients of NO-3-N concentration of soil water and TN,AN content of soil were 0.90（P0.05） and 0.92（P0.05）,and the correlation coefficient of TP concentration of soil water and AP content of soil was 0.93（P0.05） in soil layer from 60 cm to 80 cm.The correlation coefficient of NO-3-N concentration of soil water and AN content of soil was 0.94（P0.05） in soil layer from 80 cm to 100 cm.Results show that runoff of the sloping land could change effectively into subsurface flow by reverse-slope terrace,N and P concentration of soil water tended to increase in varying degrees in soil layer from 20 cm to 100 cm.Accumulation of N and P of soil were caused by the movement of N and P in soil layers.