Samples NC PC Inflow outflow
NC        
PC 0.01 * *      
inflow 0.01 * * 0.88 *    
outflow 1 * 0.02 * * 0.01 * *  
Table 3: Comparison of root length among controls (NC–negative controls, PC– positive controls) and effluents samples (two by two tables-Fisher΄s Exact Test which gives the p value property between pairs of data.); * p>0.05 samples is not characterized as being statistically significant; * *p<0.05 samples is characterized as statistically significant.