Relationship between concentration of salt
and EC can be described as a quadratic
By using this concept, we first derived
general equations to describe the
relationship between the EC as the input and
the Nitrogen (N), the Phosphorus (P) and the
Potassium (K) values as the outputs.
Then we constructed experiments in Bao
fields with various combinations of N, P, K
and measured the EC values to calibrate the
Finally, the equations of N, P, K were
generated as below.
fN(x) = 63.2526x2+14.2132x +0.1797