For these reasons, spreadsheets such as Microsoft Excel are widely suggested to make nonlinear parameter estimation (Harris 1998 Smith et al. In addition, spreadsheets have the merits of wide accessibility and powerful computation in terms of fitting nonlinear models. However, spreadsheet techniques are easier to learn than other specialized mathematical programs for nonlinear parameter estimation, because no programming skills are needed in spreadsheets to develop their own parameter estimation routines (Wraith and Or 1998). As a result, there are many software packages (such as SAS and MathCAD) that implement nonlinear parameter estimation. Nonlinear relationships are common in natural and environmental sciences (Wraith and Or 1998 Luo et al.