May be you know that the soil produce chemical reaction and in this reactions is generate electrical energy or electrolits, also it can to stock electrical energy but... How much?
Potentially negligible amounts. Even though the soil particles possess some amount of electrical charges, the energy required to harness it will be much higher. Hence, the concept will be -ve.
Thanks for your help. Evidently I consider that a fertile soil produces more energy than a soil that is not fertile. The doubt arose to me since in measuring differential of voltage I noticed that some soils had loads of 100 mV and others simply gave 0 mV. My measurements are in mV range and maybe this will affect a bit.