One-dimensional equilibrium soil-column experiment models with source (sink) reaction terms are discussed in this paper. In the case of occurring high-order chemical reactions, the zero production term in traditional models should be modified to a nonlinear term related with time (or space) and solute concentration, and then a mathematical model with nonlinear terms is put forward. Furthermore, an actual soil-column experiment in Zhangdian, Zibo is investigated. By applying an optimal perturbation algorithm, the source coefficient in the model is determined both in the cases of accurate data and inaccurate data. The inversion results show that for such inverse source coefficient problems with limited additional data, some optimal methods could be more efficient than regularization strategies, and for some real equilibrium soil-column experiments, the process of source (sink) reactions could be a key factor in the solute transportation.