摘要
•We study the reclamation process of a sodic soil by irrigation with water amended with calcium cations.•We frame this as an optimal control problem, where the amendment rate is the control and the total time is to be minimized.•The optimal solution consists in discontinuously switching the amendment rate off, from a maximum value to zero.•The solution enables a 50% reduction in remediation time, compared with the continuous use of good-quality irrigation water.•The novelty in our modeling approach is being able to search the entire strategy space for optimal time-dependent protocols.