RMSE | MAE | NS | r2 | |
mg NO3·kg−1 | mg NO3·kg−1 | |||
MLR | ||||
Nfert + DOY + Σrain + Σtemp + depth + %Clay | 101.21 | 79.25 | 0.33 | Reference |
MARS | ||||
Nfert | 110.64 | 88.63 | 0.20 | −0.19 |
DOY | 110.68 | 88.01 | 0.20 | −0.20 |
Σrain | 107.76 | 79.56 | 0.24 | −0.13 |
Σtemp | 108.87 | 86.35 | 0.22 | −0.16 |
% Clay | 123.61 | 101.64 | 0.00 | −0.49 |
Depth | 120.77 | 92.89 | 0.04 | −0.42 |
Σrain + DOY | 100.39 | 75.98 | 0.34 | 0.02 |
Σrain + DOY + Σtemp | 102.14 | 76.37 | 0.32 | −0.02 |
Σrain + DOY + Σtemp + Nfert | 83.89 | 60.91 | 0.54 | 0.31 |
Σrain + DOY + Σtemp +Nfert + depth | 83.89 | 60.91 | 0.54 | 0.31 |
Σrain + DOY + Σtemp + Nfert + %Clay | 83.89 | 60.91 | 0.54 | 0.31 |
Σrain + DOY + Σtemp + Nfert + %Clay + depth | 83.89 | 60.91 | 0.54 | 0.31 |
MLP | ||||
Nfert | 110.64 | 88.63 | 0.20 | −0.19 |
DOY | 110.74 | 87.71 | 0.20 | −0.20 |
Σrain | 107.64 | 80.11 | 0.24 | −0.13 |
Σtemp | 108.75 | 85.66 | 0.22 | −0.15 |
% Clay | 123.98 | 101.91 | −0.01 | −0.50 |
Depth | 120.77 | 92.89 | 0.04 | −0.42 |
Σrain + DOY | 103.61 | 76.98 | 0.30 | −0.05 |
Σrain + DOY + Σtemp | 100.03 | 74.37 | 0.34 | 0.02 |
Σrain + DOY + Σtemp + Nfert | 66.30 | 46.75 | 0.71 | 0.57 |
Σrain + DOY + Σtemp +Nfert + depth | 64.00 | 44.55 | 0.73 | 0.60 |
Σrain + DOY + Σtemp + Nfert + %Clay | 59.59 | 43.35 | 0.77 | 0.65 |
Σrain + DOY + Σtemp + Nfert + %Clay + depth | 58.10 | 41.62 | 0.78 | 0.67 |
LS-SVM | ||||
Nfert | 110.64 | 88.63 | 0.20 | −0.19 |
DOY | 110.42 | 87.57 | 0.20 | −0.19 |
Σrain | 109.98 | 81.13 | 0.21 | −0.18 |
Σtemp | 109.86 | 87.57 | 0.21 | −0.18 |
% Clay | 120.77 | 92.89 | 0.04 | −0.42 |
Depth | 105.47 | 82.58 | 0.13 | −0.30 |
Σrain + DOY | 100.76 | 74.59 | 0.33 | 0.01 |
Σrain + DOY + Σtemp | 98.13 | 73.36 | 0.37 | 0.06 |
Σrain + DOY + Σtemp + Nfert | 43.94 | 28.43 | 0.87 | 0.81 |
Σrain + DOY + Σtemp +Nfert + depth | 43.73 | 28.28 | 0.87 | 0.81 |
Σrain + DOY + Σtemp + Nfert + %Clay | 21.77 | 15.89 | 0.97 | 0.95 |
Σrain + DOY + Σtemp + Nfert + %Clay + depth | 21.70 | 15.93 | 0.97 | 0.95 |